.place-value-stage{--place-value-ink:#172554;--place-value-muted:#475569;width:100%;min-width:0;max-width:100%;color:var(--place-value-ink);background:linear-gradient(145deg,#f8fdff,#eff6ff);border:1px solid #bae6fd;border-radius:1.5rem;justify-items:center;gap:1rem;padding:clamp(1rem,4vw,1.7rem);display:grid;overflow:hidden}.place-value-stage>*{min-width:0;max-width:100%}.place-value-heading{text-align:center;justify-items:center;gap:.35rem;width:min(100%,42rem);display:grid}.place-value-heading h3{overflow-wrap:anywhere;margin:0;font-size:clamp(1.35rem,5vw,1.9rem);line-height:1.16}.place-value-heading p:last-child{color:var(--place-value-muted);overflow-wrap:anywhere;margin:0;font-weight:700;line-height:1.55}.place-value-piece{color:inherit;justify-items:center;gap:.25rem;display:inline-grid}.place-value-piece.is-one>i,.place-value-exchange-one .place-value-piece>i{aspect-ratio:1;background:linear-gradient(145deg,#dbeafe,#60a5fa);border:2px solid #1d4ed8;border-radius:.45rem;width:2.15rem;display:block;box-shadow:inset .18rem .18rem #fff9,0 .18rem .28rem #1e40af33}.place-value-ten-segments{background:#fed7aa;border:2px solid #7c2d12;border-radius:.48rem;grid-template-columns:repeat(10,minmax(0,1fr));width:min(100%,11.5rem);min-width:8.5rem;height:2.15rem;display:grid;overflow:hidden;box-shadow:inset .18rem .18rem #ffffff8c,0 .18rem .28rem #7c2d122e}.place-value-ten-segments i{background:linear-gradient(145deg,#ffedd5,#fb923c);border-right:1px solid #c2410c;min-width:0}.place-value-ten-segments i:last-child{border-right:0}.place-value-piece strong{color:var(--place-value-muted);font-size:.72rem;line-height:1.2}.place-value-sort-workspace,.place-value-build-workspace,.place-value-picture-workspace,.place-value-exchange-workspace,.place-value-compare-workspace,.place-value-partition-workspace,.place-value-reason-workspace,.place-value-readiness-model{background:#fff;border:1px solid #93c5fd;border-radius:1.35rem;justify-items:center;gap:.85rem;width:min(100%,46rem);padding:clamp(.75rem,3vw,1.15rem);display:grid;box-shadow:inset 0 0 0 1px #eff6ff,0 .45rem 1rem #1e40af14}.place-value-placement-area{width:100%;min-height:8.5rem;color:var(--place-value-ink);cursor:default;background:#f8fafc;border:2px dashed #93c5fd;border-radius:1.1rem;align-content:start;gap:.6rem;padding:.75rem;display:grid}.place-value-placement-area.is-bank{background:#f8fafc;border-color:#cbd5e1;min-height:7.4rem}.place-value-placement-area.is-tens{background:#fff7ed;border-color:#fdba74}.place-value-placement-area.is-ones{background:#eff6ff;border-color:#93c5fd}.place-value-placement-area.is-ready{cursor:pointer;border-style:solid;box-shadow:0 0 0 4px #6366f11f}.place-value-tray-label{flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:.35rem .75rem;display:flex}.place-value-tray-label strong{font-size:.95rem}.place-value-tray-label small{color:var(--place-value-muted);font-weight:750}.place-value-piece-row{flex-wrap:wrap;justify-content:center;align-items:flex-start;gap:.55rem;min-height:4.35rem;display:flex}.place-value-two-trays{grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;width:100%;display:grid}.place-value-piece-button{min-width:3.25rem;min-height:4.15rem;color:var(--place-value-ink);font:inherit;cursor:grab;touch-action:manipulation;background:#fff;border:2px solid #0000;border-radius:.85rem;place-items:center;padding:.4rem;display:grid}.place-value-piece-button:active{cursor:grabbing}.place-value-piece-button.is-selected{background:#eef2ff;border-color:#4f46e5;box-shadow:0 0 0 3px #6366f126}.place-value-piece-button.is-wrong{background:#fffbeb;border:3px double #b45309}.place-value-piece-button .place-value-ten-segments{width:7.25rem;min-width:7.25rem;height:1.75rem}.place-value-piece-button .place-value-piece.is-one>i{width:1.9rem}.place-value-feedback{color:#1e3a8a;text-align:center;overflow-wrap:anywhere;background:#eff6ff;border:1px solid #bfdbfe;border-radius:1rem;width:min(100%,42rem);min-height:3.25rem;margin:0;padding:.75rem 1rem;font-weight:800;line-height:1.45}.place-value-feedback.is-success{color:#166534;background:#f0fdf4;border-color:#86efac}.place-value-feedback.is-try{color:#92400e;background:#fffbeb;border-color:#fcd34d}.place-value-reset,.place-value-exchange-action{color:#1e3a8a;width:min(100%,22rem);min-height:3rem;font:inherit;touch-action:manipulation;background:#fff;border:2px solid #2563eb;border-radius:.9rem;padding:.7rem 1rem;font-weight:850}.place-value-target-card{color:#312e81;background:linear-gradient(145deg,#fff,#eef2ff);border:3px solid #4f46e5;border-radius:1.4rem;place-items:center;gap:.15rem;width:min(100%,11rem);min-height:7.5rem;padding:.75rem;display:grid;box-shadow:0 .45rem 1rem #4f46e521}.place-value-target-card span{font-size:clamp(2.75rem,12vw,4.25rem);font-weight:950;line-height:1}.place-value-target-card small{color:#475569;font-weight:800}.place-value-target-card.is-small{min-height:5.4rem}.place-value-target-card.is-small span{font-size:3rem}.place-value-number-model{grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;width:100%;display:grid}.place-value-number-model>div{background:#f8fafc;border-radius:1rem;align-content:start;justify-items:center;gap:.65rem;min-width:0;padding:.75rem;display:grid}.place-value-number-model>div:first-child{background:#fff7ed}.place-value-model-tens,.place-value-model-ones{flex-wrap:wrap;justify-content:center;gap:.35rem;width:100%;display:flex}.place-value-model-tens{gap:.35rem;display:grid}.place-value-model-tens .place-value-ten-segments{width:min(100%,10.5rem);min-width:0;height:1.65rem}.place-value-model-ones .place-value-piece.is-one>i{width:1.8rem}.place-value-base-ten-model{background:#f8fafc;border:1px solid #bfdbfe;border-radius:1rem;grid-template-columns:minmax(0,1.4fr) minmax(5rem,.6fr);align-items:center;gap:.7rem;width:min(100%,35rem);padding:.7rem;display:grid}.place-value-base-ten-rods{gap:.3rem;min-width:0;display:grid}.place-value-mini-ten{background:#fed7aa;border:2px solid #7c2d12;border-radius:.35rem;grid-template-columns:repeat(10,minmax(0,1fr));width:100%;min-width:0;height:1.25rem;display:grid;overflow:hidden}.place-value-mini-ten i{background:#fb923c;border-right:1px solid #c2410c;min-width:0}.place-value-mini-ten i:last-child{border-right:0}.place-value-base-ten-ones{grid-template-columns:repeat(4,minmax(0,1.55rem));place-content:center;gap:.25rem;min-width:0;display:grid}.place-value-base-ten-ones i{aspect-ratio:1;background:#60a5fa;border:2px solid #1d4ed8;border-radius:.3rem;width:100%;display:block}.place-value-base-ten-model.is-compact{padding:.5rem}.place-value-base-ten-model.is-compact .place-value-mini-ten{height:1rem}.place-value-base-ten-model.is-compact .place-value-base-ten-ones{grid-template-columns:repeat(4,minmax(0,1.25rem))}.place-value-digit-bank{background:#f8fafc;border:2px dashed #cbd5e1;border-radius:1rem;flex-wrap:wrap;justify-content:center;gap:.75rem;width:100%;min-height:5.5rem;padding:.65rem;display:flex}.place-value-digit-card{color:#1e3a8a;min-width:4rem;min-height:4rem;font:inherit;cursor:grab;touch-action:manipulation;background:#fff;border:2px solid #93c5fd;border-radius:1rem;place-items:center;font-size:1.65rem;font-weight:950;display:grid}.place-value-digit-card.is-selected{background:#eef2ff;border-color:#4f46e5;box-shadow:0 0 0 3px #6366f126}.place-value-digit-card.is-try{color:#92400e;background:#fffbeb;border:3px double #b45309}.place-value-digit-places{grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;width:min(100%,25rem);display:grid}.place-value-digit-area{background:#eff6ff;border:2px dashed #93c5fd;border-radius:1rem;align-content:start;justify-items:center;gap:.55rem;min-height:8rem;padding:.7rem;display:grid}.place-value-digit-area.is-ready{border-style:solid;border-color:#4f46e5}.place-value-digit-area.is-correct{background:#f0fdf4;border-color:#16a34a}.place-value-digit-area.is-try{background:#fffbeb;border:3px double #b45309}.place-value-digit-area-content{place-items:center;min-height:4rem;display:grid}.place-value-digit-area-content>span{color:#64748b;font-size:1.6rem;font-weight:900}.place-value-exchange-total{color:#1e3a8a;text-align:center;background:#dbeafe;border-radius:1rem;flex-wrap:wrap;justify-content:center;align-items:center;gap:.45rem 1rem;width:100%;padding:.65rem;display:flex}.place-value-exchange-total strong{font-size:1.1rem}.place-value-exchange-total span{font-weight:750}.place-value-exchange-grid{grid-template-columns:minmax(0,.8fr) minmax(0,1.2fr);gap:.75rem;width:100%;display:grid}.place-value-ones-bank,.place-value-bundling-tray{background:#f8fafc;border:2px dashed #93c5fd;border-radius:1.15rem;align-content:start;justify-items:center;gap:.65rem;min-height:16rem;padding:.75rem;display:grid}.place-value-ones-bank>div{grid-template-columns:repeat(2,minmax(0,3rem));place-content:center;gap:.4rem;width:100%;display:grid}.place-value-bundling-tray{background:#fff7ed;border-color:#fdba74}.place-value-bundling-tray.is-full{border-style:solid;box-shadow:inset 0 0 0 3px #ffedd5}.place-value-exchange-one{touch-action:manipulation;background:#fff;border:2px solid #0000;border-radius:.65rem;place-items:center;min-width:2.75rem;min-height:2.75rem;padding:.22rem;display:grid}.place-value-exchange-one .place-value-piece.is-one>i{width:1.65rem}.place-value-exchange-one:disabled{cursor:default}.place-value-ten-frame{background:#ffedd5;border:3px solid #c2410c;border-radius:1rem;grid-template-columns:repeat(5,minmax(0,1fr));gap:.35rem;width:min(100%,20rem);padding:.55rem;display:grid}.place-value-ten-frame>span{aspect-ratio:1;background:#fff;border:1px solid #fdba74;border-radius:.55rem;place-items:center;min-width:0;display:grid}.place-value-ten-frame>span>i{aspect-ratio:1;border:2px dashed #cbd5e1;border-radius:.35rem;width:62%}.place-value-ten-frame .place-value-exchange-one{width:100%;min-width:0;height:100%;min-height:0}.place-value-exchanged-ten{place-items:center;gap:.65rem;width:100%;padding-top:2rem;display:grid}.place-value-exchanged-ten .place-value-ten-segments{width:min(100%,16rem)}.place-value-exchanged-ten>span{color:#9a3412;font-weight:850}.place-value-exchange-action{color:#7c2d12;background:#fff7ed;border-color:#c2410c}.place-value-exchange-action:disabled{color:#64748b;cursor:not-allowed;background:#f1f5f9;border-color:#cbd5e1}.place-value-match-bank,.place-value-part-bank{background:#f8fafc;border:2px dashed #cbd5e1;border-radius:1rem;flex-wrap:wrap;justify-content:center;gap:.55rem;width:100%;min-height:5.5rem;padding:.65rem;display:flex}.place-value-match-card,.place-value-part-card{color:#1e3a8a;min-width:4.6rem;min-height:4.6rem;font:inherit;cursor:grab;touch-action:manipulation;background:#fff;border:2px solid #93c5fd;border-radius:.9rem;place-items:center;gap:.15rem;padding:.45rem .65rem;font-weight:900;display:grid}.place-value-match-card span{font-size:1.65rem;line-height:1}.place-value-match-card small{color:#475569;font-size:.7rem}.place-value-match-card.is-selected,.place-value-part-card.is-selected{background:#eef2ff;border-color:#4f46e5;box-shadow:0 0 0 3px #6366f126}.place-value-match-card.is-try,.place-value-part-card.is-try{color:#92400e;background:#fffbeb;border:3px double #b45309}.place-value-compare-panels{grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;width:100%;display:grid}.place-value-compare-panels>article{background:#f8fafc;border:1px solid #bfdbfe;border-radius:1.15rem;justify-items:center;gap:.65rem;min-width:0;padding:.75rem;display:grid}.place-value-value-slots{grid-template-columns:repeat(2,minmax(0,1fr));gap:.55rem;width:100%;display:grid}.place-value-value-slot{color:#1e3a8a;background:#eff6ff;border:2px dashed #93c5fd;border-radius:.9rem;align-content:start;justify-items:center;gap:.3rem;min-width:0;min-height:9.5rem;padding:.55rem;display:grid}.place-value-value-slot>strong{text-transform:capitalize;font-size:.8rem}.place-value-value-slot>span{font-size:1.25rem;font-weight:950}.place-value-value-slot>i{color:#64748b;font-size:1.4rem;font-style:normal;font-weight:900}.place-value-value-slot.is-ready{border-style:solid;border-color:#4f46e5}.place-value-value-slot.is-correct{background:#f0fdf4;border-color:#16a34a}.place-value-value-slot.is-try{background:#fffbeb;border:3px double #b45309}.place-value-partition-mat{grid-template-columns:repeat(2,minmax(0,1fr));gap:.65rem;width:min(100%,34rem);display:grid}.place-value-partition-whole{color:#312e81;background:#eef2ff;border:2px solid #4f46e5;border-radius:1rem;grid-column:1/-1;justify-content:space-between;align-items:center;gap:.75rem;min-height:4rem;padding:.7rem 1rem;display:flex}.place-value-partition-whole span{font-size:1.7rem;font-weight:950}.place-value-partition-slot{background:#eff6ff;border:2px dashed #93c5fd;border-radius:1rem;place-items:center;gap:.45rem;min-height:8rem;padding:.7rem;display:grid}.place-value-partition-slot.is-tens{background:#fff7ed;border-color:#fdba74}.place-value-partition-slot.is-ready{border-style:solid;box-shadow:0 0 0 3px #6366f11f}.place-value-partition-slot.is-correct{background:#f0fdf4;border-color:#16a34a}.place-value-partition-slot.is-try{background:#fffbeb;border:3px double #b45309}.place-value-partition-slot>span{color:#64748b;font-size:1.4rem;font-weight:900}.place-value-equivalent-partitions{background:#f0fdf4;border:1px solid #86efac;border-radius:1rem;justify-items:center;gap:.55rem;width:min(100%,34rem);padding:.75rem;display:grid}.place-value-equivalent-partitions>div{grid-template-columns:3.5rem 1.5rem 3.5rem minmax(4rem,1fr);align-items:center;gap:.35rem;width:min(100%,22rem);display:grid}.place-value-equivalent-partitions span{color:#1e3a8a;background:#fff;border:1px solid #60a5fa;border-radius:.7rem;place-items:center;min-height:2.7rem;font-weight:900;display:grid}.place-value-equivalent-partitions b{text-align:center}.place-value-equivalent-partitions strong{color:#166534;padding-left:.5rem}.place-value-equivalent-partitions p{color:#166534;text-align:center;margin:0;font-weight:850}.place-value-before-after{grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;width:100%;display:grid}.place-value-before-after article{text-align:center;background:#f8fafc;border:1px solid #bfdbfe;border-radius:1rem;justify-items:center;gap:.5rem;min-width:0;padding:.7rem;display:grid}.place-value-before-after article>span{color:#475569;font-weight:800}.place-value-before-after article>b{color:#166534}.place-value-reason-area{background:#f8fafc;border:2px dashed #94a3b8;border-radius:1rem;align-content:start;gap:.55rem;width:100%;min-height:7rem;padding:.7rem;display:grid}.place-value-reason-area.is-changed{background:#fff7ed;border-color:#fdba74}.place-value-reason-area.is-same{background:#f0fdf4;border-color:#86efac}.place-value-reason-area.is-ready{border-style:solid;box-shadow:0 0 0 3px #6366f11f}.place-value-reason-area>div{gap:.45rem;display:grid}.place-value-reason-trays{grid-template-columns:repeat(2,minmax(0,1fr));gap:.75rem;width:100%;display:grid}.place-value-reason-card{color:#1e3a8a;min-width:0;min-height:3.4rem;font:inherit;text-align:left;cursor:grab;touch-action:manipulation;background:#fff;border:2px solid #93c5fd;border-radius:.8rem;padding:.55rem .7rem;font-weight:800;line-height:1.35}.place-value-reason-card.is-selected{background:#eef2ff;border-color:#4f46e5;box-shadow:0 0 0 3px #6366f126}.place-value-reason-card.is-try{color:#92400e;background:#fffbeb;border:3px double #b45309}.place-value-readiness-model{width:min(100%,38rem)}.place-value-readiness-number-summary{grid-template-columns:minmax(7.75rem,8.75rem) minmax(0,1fr);align-items:stretch;gap:.75rem;width:100%;display:grid}.place-value-readiness-number-summary .place-value-target-card{width:100%;min-height:6.5rem}.place-value-readiness-number-model{align-content:center;gap:.4rem;min-width:0;display:grid}.place-value-readiness-number-model .place-value-base-ten-model{width:100%}.place-value-readiness-number-model p,.place-value-readiness-invariant{color:#1e3a8a;text-align:center;margin:0;font-weight:850;line-height:1.4}.place-value-readiness-exchange{background:#fff7ed;border:1px solid #fdba74;border-radius:1rem;grid-template-columns:minmax(0,1fr) 3.75rem minmax(0,1fr);align-items:stretch;gap:.55rem;width:100%;padding:.7rem;display:grid}.place-value-readiness-exchange-side{color:#7c2d12;background:#fff;border:1px solid #fed7aa;border-radius:.85rem;align-content:center;justify-items:center;gap:.4rem;min-width:0;min-height:6.5rem;padding:.55rem;display:grid}.place-value-readiness-exchange-side strong{text-align:center;font-size:.9rem;line-height:1.2}.place-value-readiness-loose-ones{grid-template-columns:repeat(5,minmax(0,1.2rem));place-content:center;gap:.2rem;width:100%;display:grid}.place-value-readiness-loose-ones i{aspect-ratio:1;background:#60a5fa;border:2px solid #1d4ed8;border-radius:.3rem;width:100%;display:block}.place-value-readiness-exchange-cue{color:#7c2d12;place-content:center;justify-items:center;gap:.1rem;min-width:0;display:grid}.place-value-readiness-exchange-cue b{font-size:1.65rem;line-height:1}.place-value-readiness-exchange-cue span{font-size:.78rem;font-weight:850;line-height:1.2}.place-value-readiness-one-ten{place-items:center;width:100%;min-width:0;display:grid}.place-value-readiness-one-ten .place-value-piece{width:100%;min-width:0}.place-value-readiness-one-ten .place-value-ten-segments{width:min(100%,10rem);min-width:0;height:1.8rem}.place-value-readiness-invariant{color:#166534;background:#f0fdf4;border-radius:.8rem;width:100%;padding:.55rem .75rem}.place-value-stage :where(button,[role=button]):focus-visible{outline-offset:3px;outline:3px solid #4338ca}.primary-card-place-value-card{fill:#eef2ff;stroke:#4f46e5;stroke-width:2px}.primary-card-place-value-number{fill:#312e81;text-anchor:middle;dominant-baseline:middle;font-size:31px;font-weight:950}.primary-card-place-value-ten{fill:#fb923c;stroke:#7c2d12;stroke-width:2px}.primary-card-place-value-ten-line{stroke:#c2410c;stroke-width:1px}.primary-card-place-value-one{fill:#60a5fa;stroke:#1d4ed8;stroke-width:2px}@media (max-width:560px){.place-value-stage{padding-inline:.7rem}.place-value-sort-workspace,.place-value-build-workspace,.place-value-picture-workspace,.place-value-exchange-workspace,.place-value-compare-workspace,.place-value-partition-workspace,.place-value-reason-workspace,.place-value-readiness-model{padding-inline:.6rem}.place-value-two-trays,.place-value-number-model,.place-value-exchange-grid,.place-value-compare-panels,.place-value-before-after,.place-value-reason-trays{grid-template-columns:1fr}.place-value-placement-area{min-height:7.5rem}.place-value-ones-bank,.place-value-bundling-tray{min-height:11rem}.place-value-ten-segments{min-width:7rem}.place-value-value-slot{min-height:8rem}.place-value-readiness-number-summary{grid-template-columns:1fr}.place-value-readiness-number-summary .place-value-target-card{justify-self:center;width:min(100%,9rem)}}@media (max-width:360px){.place-value-piece-button .place-value-ten-segments{width:6.25rem;min-width:6.25rem}.place-value-piece-row{gap:.35rem}.place-value-digit-places{gap:.45rem}.place-value-value-slots,.place-value-partition-mat{grid-template-columns:1fr}.place-value-partition-whole{grid-column:auto}.place-value-equivalent-partitions>div{grid-template-columns:3rem 1.2rem 3rem minmax(3.5rem,1fr)}.place-value-readiness-exchange{grid-template-columns:minmax(0,1fr) 3.2rem minmax(0,1fr);gap:.35rem;padding-inline:.45rem}.place-value-readiness-exchange-side{padding-inline:.35rem}.place-value-readiness-loose-ones{grid-template-columns:repeat(5,minmax(0,1.05rem));gap:.15rem}}@media (prefers-reduced-motion:reduce){.place-value-stage *,.place-value-stage :before,.place-value-stage :after{transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}:root[data-theme=dark] .place-value-stage{--place-value-ink:#eff6ff;--place-value-muted:#cbd5e1;background:linear-gradient(145deg,#172033,#111827);border-color:#1d4ed8}:root[data-theme=dark] :where(.place-value-sort-workspace,.place-value-build-workspace,.place-value-picture-workspace,.place-value-exchange-workspace,.place-value-compare-workspace,.place-value-partition-workspace,.place-value-reason-workspace,.place-value-readiness-model){background:#172033;border-color:#334155;box-shadow:inset 0 0 0 1px #1e3a8a}:root[data-theme=dark] .place-value-placement-area.is-bank{background:#1e293b;border-color:#64748b}:root[data-theme=dark] .place-value-placement-area.is-tens{background:#431407;border-color:#c2410c}:root[data-theme=dark] .place-value-placement-area.is-ones{background:#172554;border-color:#2563eb}:root[data-theme=dark] .place-value-piece-button,:root[data-theme=dark] .place-value-digit-card,:root[data-theme=dark] .place-value-match-card,:root[data-theme=dark] .place-value-part-card,:root[data-theme=dark] .place-value-reason-card,:root[data-theme=dark] .place-value-reset{color:#eff6ff;background:#263449}:root[data-theme=dark] .place-value-piece-button.is-selected,:root[data-theme=dark] .place-value-digit-card.is-selected,:root[data-theme=dark] .place-value-match-card.is-selected,:root[data-theme=dark] .place-value-part-card.is-selected,:root[data-theme=dark] .place-value-reason-card.is-selected{color:#eef2ff;background:#312e81;border-color:#a5b4fc}:root[data-theme=dark] .place-value-piece-button.is-wrong,:root[data-theme=dark] .place-value-digit-card.is-try,:root[data-theme=dark] .place-value-match-card.is-try,:root[data-theme=dark] .place-value-part-card.is-try,:root[data-theme=dark] .place-value-reason-card.is-try{color:#fffbeb;background:#78350f;border-color:#fbbf24}:root[data-theme=dark] .place-value-feedback{color:#dbeafe;background:#172554;border-color:#2563eb}:root[data-theme=dark] .place-value-feedback.is-success{color:#dcfce7;background:#14532d;border-color:#22c55e}:root[data-theme=dark] .place-value-feedback.is-try{color:#fffbeb;background:#78350f;border-color:#fbbf24}:root[data-theme=dark] .place-value-target-card{color:#eef2ff;background:linear-gradient(145deg,#312e81,#1e1b4b);border-color:#818cf8}:root[data-theme=dark] .place-value-target-card small{color:#cbd5e1}:root[data-theme=dark] .place-value-number-model>div{background:#1e293b}:root[data-theme=dark] .place-value-number-model>div:first-child{background:#431407}:root[data-theme=dark] .place-value-base-ten-model,:root[data-theme=dark] .place-value-digit-bank,:root[data-theme=dark] .place-value-match-bank,:root[data-theme=dark] .place-value-part-bank,:root[data-theme=dark] .place-value-compare-panels>article,:root[data-theme=dark] .place-value-before-after article,:root[data-theme=dark] .place-value-reason-area{color:#eff6ff;background:#1e293b;border-color:#475569}:root[data-theme=dark] .place-value-match-card small{color:#cbd5e1}:root[data-theme=dark] .place-value-digit-area,:root[data-theme=dark] .place-value-value-slot{color:#dbeafe;background:#172554;border-color:#2563eb}:root[data-theme=dark] :where(.place-value-digit-area.is-correct,.place-value-value-slot.is-correct,.place-value-partition-slot.is-correct){color:#dcfce7;background:#14532d;border-color:#4ade80}:root[data-theme=dark] :where(.place-value-digit-area.is-try,.place-value-value-slot.is-try,.place-value-partition-slot.is-try){color:#fffbeb;background:#78350f;border-color:#fbbf24}:root[data-theme=dark] .place-value-exchange-total{color:#dbeafe;background:#172554}:root[data-theme=dark] .place-value-ones-bank{background:#1e293b;border-color:#475569}:root[data-theme=dark] .place-value-bundling-tray{background:#431407;border-color:#c2410c}:root[data-theme=dark] .place-value-exchange-one{background:#263449}:root[data-theme=dark] .place-value-ten-frame{background:#431407;border-color:#fb923c}:root[data-theme=dark] .place-value-ten-frame>span{background:#1e293b;border-color:#9a3412}:root[data-theme=dark] .place-value-exchange-action{color:#ffedd5;background:#431407;border-color:#fb923c}:root[data-theme=dark] .place-value-exchange-action:disabled{color:#cbd5e1;background:#1e293b;border-color:#475569}:root[data-theme=dark] .place-value-partition-whole{color:#eef2ff;background:#312e81;border-color:#818cf8}:root[data-theme=dark] .place-value-partition-slot{color:#dbeafe;background:#172554;border-color:#2563eb}:root[data-theme=dark] .place-value-partition-slot.is-tens{background:#431407;border-color:#c2410c}:root[data-theme=dark] .place-value-equivalent-partitions{background:#14532d;border-color:#22c55e}:root[data-theme=dark] .place-value-equivalent-partitions span{color:#dbeafe;background:#1e293b;border-color:#60a5fa}:root[data-theme=dark] .place-value-equivalent-partitions :where(strong,p){color:#dcfce7}:root[data-theme=dark] .place-value-reason-area.is-changed{background:#431407;border-color:#c2410c}:root[data-theme=dark] .place-value-reason-area.is-same{background:#14532d;border-color:#22c55e}:root[data-theme=dark] .place-value-before-after article>span{color:#cbd5e1}:root[data-theme=dark] .place-value-before-after article>b{color:#86efac}:root[data-theme=dark] .place-value-readiness-number-model p{color:#dbeafe}:root[data-theme=dark] .place-value-readiness-exchange{color:#ffedd5;background:#431407;border-color:#c2410c}:root[data-theme=dark] .place-value-readiness-exchange-side{color:#ffedd5;background:#1e293b;border-color:#9a3412}:root[data-theme=dark] .place-value-readiness-invariant{color:#dcfce7;background:#14532d}
.addition-strategy-stage{--addition-strategy-ink:#24334f;--addition-strategy-muted:#52627d;--addition-strategy-border:#b9c7e4;--addition-strategy-panel:#f8fbff;--addition-strategy-panel-strong:#eef5ff;--addition-strategy-known:#38bdf8;--addition-strategy-more:#fb7185;--addition-strategy-moved:#34d399;border:1px solid var(--addition-strategy-border);width:100%;min-width:0;max-width:100%;color:var(--addition-strategy-ink);text-align:center;overflow-wrap:anywhere;background:radial-gradient(circle at 50% -20%,#fff 0 30%,#0000 65%),linear-gradient(145deg,#eff6ff,#fff7ed);border-radius:clamp(1.25rem,3vw,2rem);justify-items:center;gap:clamp(1rem,2vw,1.4rem);padding:clamp(1rem,4vw,2.25rem);display:grid;overflow:hidden;box-shadow:0 18px 48px #2563eb1a,inset 0 1px #fff}.addition-strategy-stage *,.addition-strategy-stage :before,.addition-strategy-stage :after{box-sizing:border-box}.addition-strategy-stage>*{min-width:0;max-width:100%}.addition-strategy-heading{gap:.35rem;width:min(100%,44rem);display:grid}.addition-strategy-heading h3{color:var(--addition-strategy-ink);margin:0;font-size:clamp(1.45rem,4vw,2.15rem)}.addition-strategy-heading>p:last-child{color:var(--addition-strategy-muted);margin:0;font-weight:650}.addition-strategy-card-copy{gap:.15rem;display:grid}.addition-strategy-card-copy strong{color:var(--addition-strategy-ink)}.addition-strategy-card-copy small{color:var(--addition-strategy-muted);font-weight:650}.addition-strategy-counter{aspect-ratio:1;background:var(--addition-strategy-known);border:3px solid #0f172a47;border-radius:999px;width:clamp(2rem,7vw,2.75rem);display:inline-block;box-shadow:inset 0 4px #ffffff80,0 4px 8px #0f172a24}.addition-strategy-counter.is-more{background:var(--addition-strategy-more)}.addition-strategy-counter.is-moved{background:var(--addition-strategy-moved)}.addition-strategy-mini-frame,.addition-make-ten-frame{background:#fff;border:3px solid #4f46e5;border-radius:1rem;grid-template-rows:repeat(2,minmax(0,1fr));grid-template-columns:repeat(5,minmax(0,1fr));gap:.32rem;width:min(100%,25rem);padding:.5rem;display:grid}.addition-strategy-mini-frame>i{aspect-ratio:1;background:#eef2ff;border:2px solid #a5b4fc;border-radius:.65rem;place-items:center;min-width:0;display:grid}.addition-strategy-mini-frame .addition-strategy-counter{width:min(86%,2.6rem)}.addition-strategy-mini-frame.is-compact{width:min(100%,17rem)}.addition-strategy-five-strip{flex-wrap:wrap;justify-content:center;gap:.4rem;display:flex}.addition-story-workspace{border:1px solid var(--addition-strategy-border);background:#ffffffbf;border-radius:1.35rem;grid-template-columns:minmax(14rem,1.15fr) minmax(11rem,.85fr);gap:.85rem;width:min(100%,48rem);padding:clamp(.75rem,2vw,1rem);display:grid}.addition-story-known,.addition-story-five,.addition-story-arrival,.addition-story-together{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.15rem;min-width:0;min-height:5rem}.addition-story-five{cursor:pointer;color:inherit;font:inherit}.addition-story-known{grid-row:span 2;align-content:center;justify-items:center;gap:.75rem;padding:.85rem;display:grid}.addition-story-arrival,.addition-story-together{align-content:center;gap:.6rem;padding:.75rem;display:grid}.addition-story-arrival.is-empty{border-style:dashed}.addition-story-five{gap:.55rem;width:100%;padding:.65rem;display:grid}.addition-story-five.is-placed{background:0 0;border:0}.addition-story-together{cursor:pointer;background:#f5f3ff;border-style:dashed;border-color:#7c3aed}.addition-story-together.is-ready{border-style:solid;border-color:#7c3aed;box-shadow:0 0 0 4px #7c3aed2e}.addition-story-together.is-filled{background:#ecfdf5;border-style:solid;border-color:#059669}.addition-story-empty-cue{color:#5b21b6;background:#fff;border:2px dashed #7c3aed;border-radius:.85rem;place-items:center;min-height:3rem;font-weight:850;display:grid}.addition-story-arrived-copy{color:var(--addition-strategy-muted);font-weight:750}.addition-start-workspace{gap:1rem;width:min(100%,45rem);display:grid}.addition-order-pair{flex-wrap:wrap;justify-content:center;align-items:center;gap:.7rem;display:flex}.addition-order-pair span{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:.9rem;padding:.55rem .8rem;font-size:1.25rem;font-weight:900}.addition-order-pair i{color:var(--addition-strategy-muted);font-size:.85rem;font-style:normal;font-weight:800}.addition-start-groups{grid-template-columns:repeat(2,minmax(0,1fr));gap:.85rem;display:grid}.addition-start-card{border:2px solid var(--addition-strategy-border);min-height:12rem;color:var(--addition-strategy-ink);background:var(--addition-strategy-panel);cursor:pointer;border-radius:1.35rem;justify-items:center;gap:.65rem;padding:1rem;display:grid;position:relative}.addition-start-card>strong{font-size:2rem}.addition-start-card.is-selected{border-color:#4f46e5;box-shadow:0 0 0 4px #6366f12e}.addition-start-marker{min-height:1.5rem;color:var(--addition-strategy-muted);letter-spacing:.06em;text-transform:uppercase;font-size:.78rem;font-weight:900}.addition-start-dot-group{grid-template-columns:repeat(4,1.35rem);justify-content:center;gap:.3rem;width:100%;display:grid}.addition-start-dot-group i{aspect-ratio:1;background:var(--addition-strategy-more);border:2px solid #0f172a40;border-radius:999px;width:1.35rem}.addition-start-dot-group.is-eight i{background:var(--addition-strategy-known)}.addition-start-route{background:var(--addition-strategy-panel-strong);border-radius:1rem;align-content:center;gap:.25rem;min-height:4.5rem;padding:.75rem;display:grid}.addition-start-route span{color:var(--addition-strategy-muted)}.addition-count-on-workspace{border:1px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.35rem;gap:1rem;width:min(100%,50rem);padding:.85rem;display:grid}.addition-count-on-copy{flex-wrap:wrap;justify-content:space-between;gap:.5rem 1rem;display:flex}.addition-count-on-copy span{color:var(--addition-strategy-muted);font-weight:750}.addition-count-on-next-copy{color:#4c1d95;background:#f5f3ff;border:2px solid #7c3aed;border-radius:.75rem;width:fit-content;margin:0 auto;padding:.42rem .7rem;font-weight:800}.addition-strategy-number-line{width:calc(100% - 2.75rem);min-height:9.5rem;margin:0 1.375rem;padding-top:3.2rem;position:relative}.addition-strategy-line-track{background:#475569;border-radius:999px;width:100%;height:.38rem;position:absolute;top:5.15rem;left:0}.addition-strategy-line-ticks{grid-template-columns:repeat(21,minmax(0,1fr));width:100%;display:grid;position:absolute;top:4.82rem;left:0;transform:translate(-.15rem)}.addition-strategy-line-ticks>span{justify-items:center;min-width:0;display:grid;position:relative}.addition-strategy-line-ticks i{background:#475569;width:.16rem;height:1rem}.addition-strategy-line-ticks b{margin-top:.3rem;font-size:clamp(.58rem,2vw,.72rem)}.addition-strategy-jump-layer{width:100%;height:3.3rem;position:absolute;top:1.25rem;left:0}.addition-strategy-jump{border:3px solid #f43f5e;border-bottom:0;border-radius:999px 999px 0 0;height:2rem;position:absolute;bottom:0}.addition-strategy-jump b{color:#be123c;font-size:.7rem;position:absolute;top:-1rem;left:50%;transform:translate(-50%)}.addition-strategy-line-marker{z-index:3;color:#fff;background:#2563eb;border:3px solid #1d4ed8;border-radius:999px;min-width:2.75rem;min-height:2.75rem;font-weight:900;position:absolute;top:3.95rem;transform:translate(-50%)}.addition-strategy-next-landing{z-index:2;pointer-events:none;background:#fff;border:2px solid #7c3aed;border-radius:.28rem;place-items:center;width:1.1rem;height:1.1rem;display:grid;position:absolute;top:4.72rem;transform:translate(-50%);box-shadow:0 0 0 3px #7c3aed24}.addition-strategy-next-landing i{background:#7c3aed;border-radius:.1rem;width:.3rem;height:.3rem}.addition-count-on-controls{flex-wrap:wrap;justify-content:center;gap:.6rem;display:flex}.addition-strategy-action,.addition-strategy-reset{color:#fff;touch-action:manipulation;background:#2563eb;border:2px solid #1d4ed8;border-radius:.9rem;min-height:2.75rem;padding:.65rem 1rem;font-weight:850}.addition-strategy-action.is-secondary,.addition-strategy-reset{color:#1e3a8a;background:#fff}.addition-count-on-result{color:#065f46;background:#d1fae5;border-radius:.9rem;place-items:center;min-height:2.75rem;padding:.55rem 1rem;font-size:1.15rem;font-weight:900;display:grid}.addition-make-ten-workspace{grid-template-columns:minmax(18rem,1.2fr) minmax(14rem,.8fr);gap:.85rem;width:min(100%,50rem);display:grid}.addition-make-ten-frame-panel,.addition-make-ten-bank{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.25rem;align-content:start;gap:.75rem;min-width:0;padding:.85rem;display:grid}.addition-make-ten-frame-copy,.addition-make-ten-bank-copy{flex-wrap:wrap;justify-content:space-between;gap:.5rem;display:flex}.addition-make-ten-frame-copy span,.addition-make-ten-bank-copy span{color:var(--addition-strategy-muted);font-weight:800}.addition-make-ten-frame{width:min(100%,28rem);margin-inline:auto}.addition-make-ten-cell{background:#eef2ff;border:2px solid #a5b4fc;border-radius:.65rem;place-items:center;min-width:0;min-height:clamp(3rem,9vw,4.5rem);padding:.2rem;display:grid}.addition-make-ten-cell.is-open{cursor:pointer;border-style:dashed}.addition-make-ten-cell.is-ready{background:#fff1f2;border-color:#f43f5e;box-shadow:inset 0 0 0 2px #f43f5e29}.addition-make-ten-cell .addition-strategy-counter{width:min(86%,2.75rem)}.addition-make-ten-bank>div:last-child{grid-template-columns:repeat(5,minmax(2.75rem,1fr));gap:.35rem;display:grid}.addition-make-ten-counter{cursor:pointer;background:0 0;border:2px solid #0000;border-radius:.8rem;place-items:center;min-width:2.75rem;min-height:3.5rem;padding:.15rem;display:grid}.addition-make-ten-counter.is-selected{background:#fff1f2;border-color:#f43f5e}.addition-make-ten-counter .addition-strategy-counter{width:min(100%,2.65rem)}.addition-make-ten-bank-space{border:2px dashed var(--addition-strategy-border);border-radius:.8rem;min-width:2.75rem;min-height:3.5rem}.addition-make-ten-partition{background:var(--addition-strategy-panel-strong);border-radius:1rem;flex-wrap:wrap;grid-column:1/-1;justify-content:center;align-items:center;gap:.55rem;min-height:3.5rem;padding:.7rem;display:flex}.addition-make-ten-partition strong{font-size:1.45rem}.addition-completed-strategy-model{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.2rem;grid-template-columns:minmax(14rem,1fr) minmax(8rem,.55fr);gap:.75rem;width:min(100%,38rem);padding:.75rem;display:grid}.addition-completed-strategy-frame{background:#fff;border:3px solid #4f46e5;border-radius:.9rem;grid-template-rows:repeat(2,minmax(0,1fr));grid-template-columns:repeat(5,minmax(0,1fr));gap:.28rem;padding:.4rem;display:grid}.addition-completed-strategy-frame i{aspect-ratio:1;background:#eef2ff;border:2px solid #a5b4fc;border-radius:.55rem;place-items:center;display:grid}.addition-completed-strategy-frame .addition-strategy-counter{width:min(84%,2.25rem)}.addition-completed-strategy-left{background:#fff1f2;border:2px dashed #fb7185;border-radius:.9rem;flex-wrap:wrap;place-content:center;gap:.35rem;min-height:5rem;padding:.6rem;display:flex}.addition-completed-strategy-left .addition-strategy-counter{width:min(28%,2.25rem)}.addition-completed-strategy-labels{color:var(--addition-strategy-muted);flex-wrap:wrap;grid-column:1/-1;justify-content:space-between;gap:.4rem;font-size:.82rem;font-weight:800;display:flex}.addition-completed-strategy-model.is-compact{grid-template-columns:minmax(12rem,1fr) minmax(7rem,.48fr);width:min(100%,31rem)}.addition-completed-strategy-model.is-compact .addition-completed-strategy-labels{justify-content:center}.addition-bridge-workspace{border:1px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.35rem;justify-items:center;gap:1rem;width:min(100%,48rem);padding:.85rem;display:grid}.addition-bridge-line{width:calc(100% - 3.5rem);min-height:9rem;margin-inline:1.75rem;padding-top:3rem;position:relative}.addition-bridge-track{background:#475569;border-radius:999px;width:100%;height:.4rem;position:absolute;top:5rem;left:0}.addition-bridge-ticks{grid-template-columns:repeat(6,minmax(0,1fr));width:100%;display:grid;position:absolute;top:4.65rem;left:0;transform:translate(-.15rem)}.addition-bridge-ticks span{justify-items:center;min-width:0;display:grid}.addition-bridge-ticks i{background:#475569;width:.18rem;height:1.15rem}.addition-bridge-ticks b{margin-top:.28rem;font-size:.8rem}.addition-bridge-jump-layer{width:100%;height:3.3rem;position:absolute;top:1.2rem;left:0}.addition-bridge-jump{border:3px solid #f43f5e;border-bottom:0;border-radius:999px 999px 0 0;height:2.15rem;position:absolute;bottom:0}.addition-bridge-jump.is-3{border-color:#7c3aed;height:2.75rem}.addition-bridge-jump b{color:#881337;background:#fff1f2;border:2px solid #be123c;border-radius:.55rem;width:max-content;max-width:9rem;padding:.24rem .48rem;font-size:clamp(.78rem,2.5vw,.95rem);line-height:1.05;position:absolute;top:-1.35rem;left:50%;transform:translate(-50%)}.addition-bridge-jump.is-3 b{color:#4c1d95;background:#f5f3ff;border-color:#6d28d9}.addition-bridge-marker{z-index:3;color:#fff;background:#2563eb;border:3px solid #1d4ed8;border-radius:999px;min-width:2.75rem;min-height:2.75rem;font-weight:900;position:absolute;top:3.8rem;transform:translate(-50%)}.addition-bridge-next{z-index:2;color:#4c1d95;background:#f5f3ff;border:3px dashed #7c3aed;border-radius:.7rem;min-width:2.75rem;min-height:2.75rem;position:absolute;top:3.85rem;transform:translate(-50%)}.addition-bridge-instruction{color:#4c1d95;background:#f5f3ff;border:2px solid #7c3aed;border-radius:.9rem;width:min(100%,30rem);margin:0;padding:.65rem .8rem;font-weight:850}.addition-bridge-controls{flex-wrap:wrap;justify-content:center;gap:.6rem;display:flex}.addition-bridge-result{color:#065f46;background:#d1fae5;border-radius:.9rem;place-items:center;min-height:2.75rem;padding:.55rem 1rem;font-size:1.15rem;font-weight:900;display:grid}.addition-represent-workspace,.addition-explain-workspace{border:1px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.35rem;justify-items:center;gap:.85rem;width:min(100%,50rem);padding:.85rem;display:grid}.addition-strategy-token-bank,.addition-explanation-bank{border:2px dashed var(--addition-strategy-border);background:var(--addition-strategy-panel-strong);border-radius:1rem;gap:.55rem;width:100%;min-height:5rem;padding:.7rem;display:grid}.addition-strategy-token-bank>div,.addition-explanation-bank>div{flex-wrap:wrap;justify-content:center;gap:.5rem;display:flex}.addition-strategy-token,.addition-explanation-card{min-width:0;min-height:2.75rem;color:var(--addition-strategy-ink);font:inherit;overflow-wrap:anywhere;cursor:grab;touch-action:manipulation;background:#f5f3ff;border:2px solid #7c3aed;border-radius:.85rem;padding:.6rem .8rem;font-weight:850}.addition-strategy-token.is-selected,.addition-explanation-card.is-selected{border-color:#f43f5e;box-shadow:0 0 0 3px #f43f5e2e}.addition-strategy-slot-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:.65rem;width:100%;display:grid}.addition-strategy-slot{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel-strong);cursor:pointer;border-radius:1rem;align-content:center;justify-items:center;gap:.35rem;min-width:0;min-height:7.5rem;padding:.65rem;display:grid}.addition-strategy-slot.is-ready{border-color:#f43f5e}.addition-strategy-slot>span{color:#fff;background:#4f46e5;border-radius:999px;place-items:center;width:1.65rem;height:1.65rem;font-size:.8rem;font-weight:900;display:grid}.addition-strategy-slot>i{color:var(--addition-strategy-muted);font-size:.82rem;font-style:normal;font-weight:700}.addition-strategy-slot .addition-strategy-token{width:min(100%,13rem)}.addition-explanation-slots{gap:.55rem;width:100%;display:grid}.addition-explanation-slot{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel-strong);cursor:pointer;border-radius:1rem;grid-template-columns:2.25rem minmax(0,1fr);align-items:center;gap:.55rem;min-height:4.25rem;padding:.55rem;display:grid}.addition-explanation-slot.is-ready{border-color:#f43f5e}.addition-explanation-slot>span{color:#fff;background:#4f46e5;border-radius:999px;place-items:center;width:2rem;height:2rem;font-weight:900;display:grid}.addition-explanation-slot>i{color:var(--addition-strategy-muted);font-style:normal;font-weight:700}.addition-explanation-slot .addition-explanation-card{cursor:grab;width:100%}.addition-readiness-reminder{border:1px solid var(--addition-strategy-border);background:var(--addition-strategy-panel);border-radius:1.35rem;justify-items:center;gap:.85rem;width:min(100%,44rem);padding:.85rem;display:grid}.addition-readiness-reminder>div:last-child{grid-template-columns:repeat(3,minmax(0,1fr));gap:.55rem;width:100%;display:grid}.addition-readiness-reminder>div:last-child span{border:2px solid var(--addition-strategy-border);background:var(--addition-strategy-panel-strong);border-radius:1rem;align-content:center;justify-items:center;gap:.35rem;min-height:5.5rem;padding:.55rem;font-weight:800;display:grid}.addition-readiness-reminder b{color:#fff;background:#4f46e5;border-radius:999px;place-items:center;width:1.8rem;height:1.8rem;display:grid}.addition-strategy-feedback{border:2px solid var(--addition-strategy-border);width:min(100%,44rem);min-height:3.3rem;color:var(--addition-strategy-ink);background:var(--addition-strategy-panel);border-radius:1rem;margin:0;padding:.75rem .9rem;font-weight:750}.addition-strategy-feedback.is-success{color:#065f46;background:#d1fae5;border-color:#059669}.addition-strategy-feedback.is-try{color:#78350f;background:#fef3c7;border-color:#d97706}.addition-strategy-stage :where(button,[role=button]):focus-visible{outline-offset:3px;outline:4px solid #f59e0b}@media (max-width:620px){.addition-story-workspace,.addition-make-ten-workspace,.addition-completed-strategy-model,.addition-completed-strategy-model.is-compact{grid-template-columns:1fr}.addition-story-known{grid-row:auto}.addition-make-ten-partition{grid-column:auto}.addition-completed-strategy-labels{grid-column:auto;justify-content:center}}@media (max-width:430px){.addition-strategy-stage{gap:.9rem;padding:.9rem .7rem 1.15rem}.addition-start-groups{grid-template-columns:1fr}.addition-start-card{min-height:9.5rem}.addition-strategy-number-line{width:calc(100% - 2.25rem);margin-inline:1.125rem}.addition-bridge-line{width:calc(100% - 2.5rem);margin-inline:1.25rem}.addition-bridge-jump b{max-width:6.5rem;font-size:.76rem}.addition-make-ten-bank>div:last-child{grid-template-columns:repeat(5,minmax(2.75rem,1fr));padding-bottom:.25rem;overflow-x:auto}.addition-strategy-slot-grid,.addition-readiness-reminder>div:last-child{grid-template-columns:1fr}}@media (prefers-reduced-motion:reduce){.addition-strategy-stage *,.addition-strategy-stage :before,.addition-strategy-stage :after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important}}:root[data-theme=dark] .addition-strategy-stage{--addition-strategy-ink:#e6edf9;--addition-strategy-muted:#c5d1e5;--addition-strategy-border:#526482;--addition-strategy-panel:#172238;--addition-strategy-panel-strong:#1c2b47;background:radial-gradient(circle at 50% -20%,#273552 0 28%,#0000 64%),linear-gradient(145deg,#121a2b,#252032);border-color:#415371;box-shadow:0 20px 55px #0000004d,inset 0 1px #ffffff0f}:root[data-theme=dark] .addition-story-workspace{background:#0f172ab3}:root[data-theme=dark] .addition-story-together{background:#292447;border-color:#a78bfa}:root[data-theme=dark] .addition-story-together.is-filled{background:#123c34;border-color:#34d399}:root[data-theme=dark] .addition-story-empty-cue{color:#ede9fe;background:#172238;border-color:#a78bfa}:root[data-theme=dark] :where(.addition-strategy-mini-frame,.addition-make-ten-frame){background:#111827;border-color:#818cf8}:root[data-theme=dark] :where(.addition-strategy-mini-frame>i,.addition-make-ten-cell,.addition-completed-strategy-frame i){background:#202b45;border-color:#6366f1}:root[data-theme=dark] .addition-completed-strategy-frame{background:#111827;border-color:#818cf8}:root[data-theme=dark] .addition-completed-strategy-left{background:#4c1d2c;border-color:#fb7185}:root[data-theme=dark] .addition-strategy-action.is-secondary,:root[data-theme=dark] .addition-strategy-reset{color:#dbeafe;background:#1e293b}:root[data-theme=dark] .addition-strategy-next-landing{background:#111827;border-color:#c4b5fd;box-shadow:0 0 0 3px #c4b5fd2e}:root[data-theme=dark] .addition-strategy-next-landing i{background:#c4b5fd}:root[data-theme=dark] :where(.addition-count-on-next-copy,.addition-bridge-instruction,.addition-bridge-next){color:#ede9fe;background:#292447;border-color:#a78bfa}:root[data-theme=dark] .addition-strategy-jump b{color:#fda4af}:root[data-theme=dark] .addition-bridge-jump b{color:#ffe4e6;background:#4c1d2c;border-color:#fb7185}:root[data-theme=dark] .addition-bridge-jump.is-3 b{color:#ede9fe;background:#292447;border-color:#c4b5fd}:root[data-theme=dark] .addition-count-on-result,:root[data-theme=dark] .addition-bridge-result,:root[data-theme=dark] .addition-strategy-feedback.is-success{color:#d1fae5;background:#064e3b}:root[data-theme=dark] .addition-strategy-feedback.is-try{color:#fef3c7;background:#78350f}:root[data-theme=dark] :where(.addition-make-ten-cell.is-ready,.addition-make-ten-counter.is-selected){background:#4c1d2c}:root[data-theme=dark] :where(.addition-strategy-token,.addition-explanation-card){background:#2e2851;border-color:#a78bfa}
.subtraction-strategy-stage{--subtraction-ink:#253451;--subtraction-muted:#52627c;--subtraction-border:#b8c7df;--subtraction-panel:#f8fbff;--subtraction-panel-strong:#eef5ff;--subtraction-stays:#38bdf8;--subtraction-moves:#fb7185;--subtraction-away:#f59e0b;border:1px solid var(--subtraction-border);width:100%;min-width:0;max-width:100%;color:var(--subtraction-ink);text-align:center;overflow-wrap:anywhere;background:radial-gradient(circle at 50% -20%,#fff 0 30%,#0000 65%),linear-gradient(145deg,#eef8ff,#fff7ed);border-radius:clamp(1.25rem,3vw,2rem);justify-items:center;gap:clamp(1rem,2vw,1.4rem);padding:clamp(1rem,4vw,2.25rem);display:grid;overflow:hidden;box-shadow:0 18px 48px #2563eb1a,inset 0 1px #fff}.subtraction-strategy-stage *,.subtraction-strategy-stage :before,.subtraction-strategy-stage :after{box-sizing:border-box}.subtraction-strategy-stage>*{min-width:0;max-width:100%}.subtraction-strategy-heading{gap:.35rem;width:min(100%,45rem);display:grid}.subtraction-strategy-heading h3{color:var(--subtraction-ink);margin:0;font-size:clamp(1.45rem,4vw,2.15rem)}.subtraction-strategy-heading>p:last-child{color:var(--subtraction-muted);margin:0;font-weight:700}.subtraction-strategy-counter{aspect-ratio:1;background:var(--subtraction-stays);border:3px solid #0f172a47;border-radius:999px;width:clamp(1.9rem,7vw,2.65rem);display:inline-block;box-shadow:inset 0 4px #ffffff80,0 4px 8px #0f172a24}.subtraction-strategy-counter.is-moves{background:var(--subtraction-moves)}.subtraction-strategy-counter.is-away{background:var(--subtraction-away)}.subtraction-strategy-ten-frame{background:#fff;border:3px solid #4f46e5;border-radius:1rem;grid-template-rows:repeat(2,minmax(0,1fr));grid-template-columns:repeat(5,minmax(0,1fr));gap:.3rem;width:min(100%,22rem);padding:.45rem;display:grid}.subtraction-strategy-ten-frame>i{aspect-ratio:1;background:#eef2ff;border:2px solid #a5b4fc;border-radius:.62rem;place-items:center;min-width:0;display:grid}.subtraction-strategy-ten-frame .subtraction-strategy-counter{width:min(84%,2.45rem)}.subtraction-strategy-five-group{flex-wrap:wrap;justify-content:center;gap:.35rem;display:flex}.subtraction-story-workspace{border:1px solid var(--subtraction-border);background:#ffffffc2;border-radius:1.35rem;grid-template-columns:minmax(20rem,1.35fr) minmax(11rem,.65fr);gap:.9rem;width:min(100%,52rem);padding:.85rem;display:grid}.subtraction-story-whole,.subtraction-story-away{border:2px solid var(--subtraction-border);background:var(--subtraction-panel);border-radius:1.2rem;align-content:center;gap:.75rem;min-width:0;padding:.85rem;display:grid}.subtraction-story-whole{border-width:3px;border-color:#4f46e5}.subtraction-story-whole.is-ready,.subtraction-story-away.is-ready{box-shadow:0 0 0 4px #7c3aed2e}.subtraction-story-whole-label{color:#312e81;background:#e0e7ff;border-radius:.85rem;gap:.15rem;padding:.55rem;display:grid}.subtraction-story-whole-label span{color:#3730a3;font-size:.86rem;font-weight:750}.subtraction-story-parts{grid-template-columns:minmax(13rem,1fr) minmax(9rem,.65fr);gap:.65rem;display:grid}.subtraction-story-eight,.subtraction-story-five{border:2px solid var(--subtraction-border);min-width:0;min-height:10rem;color:var(--subtraction-ink);font:inherit;background:#fff;border-radius:1rem;align-content:center;justify-items:center;gap:.55rem;padding:.65rem;display:grid}.subtraction-story-eight>strong{font-size:1.5rem}.subtraction-story-eight small,.subtraction-story-away small{color:var(--subtraction-muted);font-weight:700}.subtraction-story-five{cursor:grab;touch-action:manipulation}.subtraction-story-five.is-selected{border-color:#e11d48;box-shadow:0 0 0 4px #e11d482e}.subtraction-story-away{background:#fff7ed;border-style:dashed;border-color:#9a3412}.subtraction-story-away.is-filled{background:#ecfdf5;border-style:solid;border-color:#047857}.subtraction-story-place-button,.subtraction-story-return-zone{color:#4c1d95;min-height:3.25rem;font:inherit;background:#fff;border:2px dashed #7c3aed;border-radius:.9rem;padding:.65rem;font-weight:850}.subtraction-story-place-button:disabled,.subtraction-story-return-zone:disabled{border-color:var(--subtraction-border);color:var(--subtraction-muted);background:var(--subtraction-panel-strong)}.subtraction-take-workspace{grid-template-columns:minmax(20rem,1.25fr) minmax(13rem,.75fr);gap:.85rem;width:min(100%,52rem);display:grid}.subtraction-take-whole,.subtraction-away-tray{border:2px solid var(--subtraction-border);background:var(--subtraction-panel);border-radius:1.2rem;align-content:start;justify-items:center;gap:.75rem;min-width:0;padding:.85rem;display:grid}.subtraction-take-copy{flex-wrap:wrap;justify-content:space-between;gap:.5rem 1rem;width:100%;display:flex}.subtraction-take-copy span{color:var(--subtraction-muted);font-weight:800}.subtraction-action-hint{color:#3730a3;background:#eef2ff;border-radius:.85rem;width:min(100%,45rem);margin:0;padding:.55rem .75rem;font-weight:800}.subtraction-eight-stay-area{background:#f0f9ff;border:2px solid #0369a1;border-radius:1rem;justify-items:center;gap:.5rem;width:100%;padding:.7rem;display:grid}.subtraction-eight-stay-area>strong{color:#075985}.subtraction-take-part{background:#fff1f2;border:2px solid #e11d48;border-radius:1rem;justify-items:center;gap:.55rem;width:100%;padding:.7rem;display:grid}.subtraction-take-part>strong{color:#9f1239}.subtraction-take-bank{flex-wrap:wrap;justify-content:center;gap:.35rem;width:100%;min-height:3.35rem;display:flex}.subtraction-take-counter{min-width:2.75rem;min-height:3.35rem;color:inherit;cursor:grab;touch-action:manipulation;background:0 0;border:2px solid #0000;border-radius:.8rem;place-items:center;padding:.15rem;display:grid}.subtraction-take-counter.is-selected{background:#fff1f2;border-color:#e11d48;box-shadow:0 0 0 3px #e11d4829}.subtraction-return-selected{color:#9f1239;min-height:2.75rem;font:inherit;background:#fff;border:2px solid #be123c;border-radius:.8rem;padding:.55rem .75rem;font-weight:850}.subtraction-away-tray{background:#fff7ed;border-color:#c2410c}.subtraction-away-slots{grid-template-columns:repeat(5,minmax(2.75rem,1fr));grid-auto-rows:4rem;align-items:stretch;gap:.35rem;width:100%;display:grid}.subtraction-away-slot{color:#9a3412;min-width:2.75rem;height:4rem;font:inherit;touch-action:manipulation;background:#fff;border:2px dashed #c2410c;border-radius:.8rem;place-items:center;padding:0;display:grid;position:relative;overflow:hidden}.subtraction-away-slot.is-ready{border-style:solid;box-shadow:inset 0 0 0 3px #ea580c24}.subtraction-away-slot.is-filled{border-style:solid;overflow:visible}.subtraction-away-slot>.subtraction-take-counter.is-away-slot-counter{justify-content:center;align-items:center;width:auto;min-width:0;height:auto;min-height:0;margin:0;padding:.2rem;line-height:0;display:flex;position:absolute;inset:0}.subtraction-away-slot>.subtraction-take-counter.is-away-slot-counter .subtraction-strategy-counter{flex:none;width:clamp(1.9rem,7vw,2.45rem);min-width:clamp(1.9rem,7vw,2.45rem);height:clamp(1.9rem,7vw,2.45rem);min-height:clamp(1.9rem,7vw,2.45rem);margin:0;display:block}.subtraction-away-note{margin-top:.35rem;display:block}.subtraction-away-tray>small{color:#7c2d12;font-weight:750}.subtraction-count-back-workspace,.subtraction-difference-workspace{border:1px solid var(--subtraction-border);background:var(--subtraction-panel);border-radius:1.35rem;justify-items:center;gap:.9rem;width:min(100%,52rem);padding:.85rem;display:grid}.subtraction-count-back-copy{flex-wrap:wrap;justify-content:space-between;gap:.5rem 1rem;width:100%;display:flex}.subtraction-count-back-copy span{color:var(--subtraction-muted);font-weight:800}.subtraction-next-landing{color:#4c1d95;background:#f5f3ff;border:2px solid #7c3aed;border-radius:.75rem;width:fit-content;margin:0;padding:.45rem .7rem;font-weight:850}.subtraction-number-line{width:calc(100% - 2.75rem);min-height:9.5rem;margin:0 1.375rem;padding-top:3.2rem;position:relative}.subtraction-number-line-track{background:#475569;border-radius:999px;width:100%;height:.38rem;position:absolute;top:5.15rem;left:0}.subtraction-number-line-ticks{grid-template-columns:repeat(21,minmax(0,1fr));width:100%;display:grid;position:absolute;top:4.82rem;left:0;transform:translate(-.15rem)}.subtraction-number-line-ticks>span{justify-items:center;min-width:0;display:grid}.subtraction-number-line-ticks i{background:#475569;width:.16rem;height:1rem}.subtraction-number-line-ticks b{margin-top:.3rem;font-size:clamp(.58rem,2vw,.72rem)}.subtraction-jump-layer{width:100%;height:3.4rem;position:absolute;top:1.2rem;left:0}.subtraction-back-jump{border:3px solid #e11d48;border-bottom:0;border-radius:999px 999px 0 0;height:2rem;position:absolute;bottom:0}.subtraction-back-jump b{color:#9f1239;font-size:.72rem;position:absolute;top:-1rem;left:50%;transform:translate(-50%)}.subtraction-line-marker{z-index:3;color:#fff;background:#2563eb;border:3px solid #1d4ed8;border-radius:999px;place-items:center;min-width:2.75rem;min-height:2.75rem;font-weight:900;display:grid;position:absolute;top:3.95rem;transform:translate(-50%)}.subtraction-next-marker{z-index:2;background:#fff;border:2px solid #7c3aed;border-radius:.3rem;place-items:center;width:1.15rem;height:1.15rem;display:grid;position:absolute;top:4.68rem;transform:translate(-50%);box-shadow:0 0 0 3px #7c3aed24}.subtraction-next-marker i{background:#7c3aed;border-radius:.1rem;width:.32rem;height:.32rem}.subtraction-strategy-controls{flex-wrap:wrap;justify-content:center;gap:.6rem;display:flex}.subtraction-strategy-action,.subtraction-strategy-reset{color:#fff;min-height:2.75rem;font:inherit;touch-action:manipulation;background:#2563eb;border:2px solid #1d4ed8;border-radius:.9rem;padding:.65rem 1rem;font-weight:850}.subtraction-strategy-action.is-secondary,.subtraction-strategy-reset{color:#1e3a8a;background:#fff}.subtraction-strategy-action:disabled,.subtraction-strategy-reset:disabled{border-color:var(--subtraction-border);color:var(--subtraction-muted);background:var(--subtraction-panel-strong)}.subtraction-shared-origin{width:100%;color:var(--subtraction-muted);text-align:left;align-items:center;gap:.45rem;font-weight:850;display:flex}.subtraction-shared-origin span{background:#4f46e5;border-radius:999px;width:.35rem;height:2rem}.subtraction-aligned-bars{background:var(--subtraction-panel-strong);border-radius:1rem;gap:.8rem;width:100%;padding:.85rem;display:grid}.subtraction-bar-row{grid-template-columns:2.75rem minmax(0,1fr);align-items:center;gap:.55rem;display:grid}.subtraction-bar-row>strong{color:#312e81;background:#e0e7ff;border-radius:.75rem;place-items:center;min-height:2.75rem;font-size:1.15rem;display:grid}.subtraction-compare-track{grid-template-columns:minmax(5rem,8fr) repeat(5,minmax(2.75rem,1fr));gap:0;min-width:0;display:grid}.subtraction-shared-unit,.subtraction-extra-unit{border-radius:0;min-width:0;min-height:3.25rem}.subtraction-shared-unit{color:#075985;background-color:#e0f2fe;background-image:repeating-linear-gradient(90deg,#0000 0 calc(12.5% - 1px),#7dd3fc calc(12.5% - 1px) 12.5%);border:2px solid #0369a1;border-radius:.7rem 0 0 .7rem;place-items:center;font-size:.82rem;display:grid;box-shadow:inset 0 3px #ffffff8c}.subtraction-extra-unit{color:#7c2d12;font:inherit;touch-action:manipulation;background:#ffedd5;border:2px solid #c2410c;border-left:0;place-items:center;padding:0;font-weight:900;display:grid}.subtraction-extra-unit:last-child{border-radius:0 .7rem .7rem 0}.subtraction-extra-unit.is-next{z-index:1;position:relative;box-shadow:inset 0 0 0 3px #7c3aed4d}.subtraction-extra-unit.is-counted{color:#065f46;background:#d1fae5;border-color:#047857}.subtraction-extra-unit.is-counted+.subtraction-extra-unit{border-left:2px solid #c2410c}.subtraction-extra-unit>span{font-size:1.15rem;line-height:1}.subtraction-compare-track.is-eight-track .subtraction-shared-unit{border-radius:.7rem}.subtraction-comparison-key{color:var(--subtraction-muted);flex-wrap:wrap;justify-content:center;gap:.55rem 1rem;font-weight:800;display:flex}.subtraction-comparison-key>span{align-items:center;gap:.35rem;display:inline-flex}.subtraction-comparison-key i{background:#e0f2fe;border:2px solid #0369a1;border-radius:.3rem;width:1.1rem;height:1.1rem}.subtraction-comparison-key i.is-extra{background:#ffedd5;border-color:#c2410c}.subtraction-difference-instruction{color:var(--subtraction-muted);margin:0;font-weight:850}.subtraction-strategy-feedback{border:2px solid var(--subtraction-border);width:min(100%,45rem);min-height:3.3rem;color:var(--subtraction-ink);background:var(--subtraction-panel);border-radius:1rem;margin:0;padding:.75rem .9rem;font-weight:750}.subtraction-strategy-feedback.is-success{color:#065f46;background:#d1fae5;border-color:#047857}.subtraction-strategy-choice-workspace,.subtraction-represent-workspace,.subtraction-explain-workspace{border:1px solid var(--subtraction-border);background:var(--subtraction-panel);text-align:left;border-radius:1.35rem;justify-items:stretch;gap:.9rem;width:min(100%,52rem);padding:.9rem;display:grid}.subtraction-equation-bank,.subtraction-explanation-bank{border:2px solid var(--subtraction-border);background:var(--subtraction-panel-strong);border-radius:1rem;gap:.6rem;padding:.75rem;display:grid}.subtraction-equation-bank>div,.subtraction-explanation-bank>div{flex-wrap:wrap;gap:.55rem;min-height:3.35rem;display:flex}.subtraction-equation-token,.subtraction-explanation-card{color:#312e81;min-height:3rem;font:inherit;text-align:left;touch-action:manipulation;cursor:grab;background:#fff;border:2px solid #4f46e5;border-radius:.85rem;padding:.65rem .8rem;font-weight:850;line-height:1.25}.subtraction-equation-token.is-selected,.subtraction-explanation-card.is-selected{border-color:#c2410c;box-shadow:0 0 0 4px #ea580c2e}.subtraction-equation-token.is-correct,.subtraction-explanation-card.is-correct{color:#065f46;background:#ecfdf5;border-color:#047857}.subtraction-equation-token.is-editable,.subtraction-explanation-card.is-editable{border-style:dashed;border-color:#c2410c}.subtraction-story-progress{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:.55rem;display:flex}.subtraction-story-progress>div{gap:.35rem;display:flex}.subtraction-story-progress span{border:2px solid var(--subtraction-border);background:#fff;border-radius:999px;width:.9rem;height:.9rem}.subtraction-story-progress span.is-current{border-color:#4f46e5;box-shadow:0 0 0 3px #4f46e529}.subtraction-story-progress span.is-solved{background:#34d399;border-color:#047857}.subtraction-current-story{text-align:center;background:#eef2ff;border:3px solid #4f46e5;border-radius:1.1rem;place-items:center;gap:.35rem;min-height:7.5rem;padding:1rem;display:grid}.subtraction-current-story small{color:#4338ca;font-weight:800}.subtraction-current-story strong{font-size:clamp(1.25rem,4vw,1.8rem)}.subtraction-strategy-choice-buttons{grid-template-columns:repeat(3,minmax(0,1fr));gap:.65rem;display:grid}.subtraction-strategy-choice-buttons>button{border:2px solid var(--subtraction-border);min-width:0;min-height:8.5rem;color:var(--subtraction-ink);font:inherit;text-align:center;touch-action:manipulation;background:#fff;border-radius:1rem;align-content:center;justify-items:center;gap:.4rem;padding:.75rem;display:grid}.subtraction-strategy-choice-buttons>button>span{color:#1e3a8a;background:#dbeafe;border-radius:.7rem;place-items:center;width:100%;min-height:2.75rem;padding:.35rem;font-weight:900;display:grid}.subtraction-strategy-choice-buttons>button small{color:var(--subtraction-muted);font-weight:700}.subtraction-strategy-choice-buttons>button.is-selected{border-color:#c2410c;box-shadow:0 0 0 4px #ea580c29}.subtraction-strategy-choice-buttons>button.is-correct{background:#ecfdf5;border-color:#047857}.subtraction-helpful-reminder{color:var(--subtraction-muted);text-align:center;margin:0;font-weight:750}.subtraction-place-selected{color:#4c1d95;min-height:2.75rem;font:inherit;touch-action:manipulation;background:#f5f3ff;border:2px solid #7c3aed;border-radius:.8rem;padding:.55rem .7rem;font-weight:850}.subtraction-place-selected:disabled{border-color:var(--subtraction-border);color:var(--subtraction-muted);background:var(--subtraction-panel-strong)}.subtraction-compact-model{border:2px solid var(--subtraction-border);text-align:center;background:#fff;border-radius:1rem;grid-template-columns:minmax(11rem,1fr) minmax(12rem,1fr);align-items:center;gap:.55rem .9rem;padding:.7rem;display:grid}.subtraction-compact-whole{gap:.35rem;display:grid}.subtraction-compact-whole>span{border:2px solid #4f46e5;border-radius:.75rem;grid-template-columns:8fr 5fr;min-height:3.2rem;display:grid;overflow:hidden}.subtraction-compact-whole b,.subtraction-compact-whole i{place-items:center;padding:.35rem;font-style:normal;display:grid}.subtraction-compact-whole b{color:#075985;background:#e0f2fe}.subtraction-compact-whole i{color:#7c2d12;background:#ffedd5;border-left:2px dashed #c2410c}.subtraction-compact-gap{grid-template-columns:auto repeat(5,minmax(1.7rem,1fr)) auto;align-items:center;gap:.2rem;display:grid}.subtraction-compact-gap>span{font-weight:900}.subtraction-compact-gap>i{color:#7c2d12;background:#ffedd5;border:2px solid #c2410c;border-radius:.5rem;place-items:center;min-height:2.5rem;font-style:normal;font-weight:850;display:grid}.subtraction-compact-model>small{color:var(--subtraction-muted);grid-column:2;font-weight:850}.subtraction-model-connection{color:var(--subtraction-muted);text-align:center;margin:0;font-weight:800}.subtraction-equation-slots{grid-template-columns:repeat(2,minmax(0,1fr));gap:.65rem;display:grid}.subtraction-equation-slot{border:2px dashed var(--subtraction-border);background:#fff;border-radius:1rem;align-content:start;gap:.4rem;min-width:0;min-height:9.5rem;padding:.7rem;display:grid}.subtraction-equation-slot.is-ready{border-color:#7c3aed}.subtraction-equation-slot>small{color:var(--subtraction-muted);font-weight:700}.subtraction-equation-slot>div{place-items:stretch stretch;min-height:3rem;display:grid}.subtraction-equation-slot>div>span{color:var(--subtraction-muted);text-align:center;align-self:center;font-weight:750}.subtraction-equation-slot .subtraction-equation-token{text-align:center;width:100%}.subtraction-explanation-slots{gap:.55rem;display:grid}.subtraction-explanation-slot{border:2px dashed var(--subtraction-border);background:#fff;border-radius:.9rem;grid-template-columns:2.75rem minmax(0,1fr) minmax(10rem,auto);align-items:center;gap:.55rem;min-width:0;padding:.55rem;display:grid}.subtraction-explanation-slot.is-ready{border-color:#7c3aed}.subtraction-explanation-slot>strong{color:#fff;background:#4f46e5;border-radius:999px;place-items:center;width:2.75rem;min-height:2.75rem;display:grid}.subtraction-explanation-slot>div{min-height:3rem;display:grid}.subtraction-explanation-slot>div>span{color:var(--subtraction-muted);align-self:center;font-weight:750}.subtraction-explanation-card{width:100%}.subtraction-readiness-reminder{border:1px solid var(--subtraction-border);background:var(--subtraction-panel);border-radius:1.2rem;grid-template-columns:repeat(3,minmax(0,1fr));gap:.65rem;width:min(100%,48rem);padding:.75rem;display:grid}.subtraction-readiness-reminder>div{border:2px solid var(--subtraction-border);background:#fff;border-radius:.9rem;align-content:center;gap:.45rem;min-width:0;min-height:6.5rem;padding:.65rem;display:grid}.subtraction-readiness-reminder span{color:#1e3a8a;font-weight:900}.subtraction-strategy-stage :where(button,[role=button],[tabindex="0"]):focus-visible{outline-offset:3px;outline:4px solid #f59e0b}@media (max-width:680px){.subtraction-story-workspace,.subtraction-take-workspace,.subtraction-strategy-choice-buttons{grid-template-columns:1fr}.subtraction-strategy-choice-buttons>button{text-align:left;grid-template-columns:minmax(7rem,.8fr) minmax(0,1.2fr);min-height:5.5rem}.subtraction-strategy-choice-buttons>button>span{grid-row:1/3}.subtraction-readiness-reminder{grid-template-columns:1fr}.subtraction-readiness-reminder>div{min-height:5rem}}@media (max-width:520px){.subtraction-story-parts{grid-template-columns:1fr}.subtraction-story-eight,.subtraction-story-five{min-height:8rem}.subtraction-number-line{width:calc(100% - 2.25rem);margin-inline:1.125rem}.subtraction-away-slots{grid-template-columns:repeat(5,minmax(2.75rem,1fr));padding-bottom:.25rem;overflow-x:auto}.subtraction-compact-model,.subtraction-equation-slots{grid-template-columns:1fr}.subtraction-compact-model>small{grid-column:1}.subtraction-explanation-slot{grid-template-columns:2.75rem minmax(0,1fr)}.subtraction-explanation-slot .subtraction-place-selected{grid-column:1/-1}}@media (max-width:390px){.subtraction-strategy-stage{gap:.9rem;padding:.9rem .65rem 1.15rem}.subtraction-aligned-bars{padding-inline:.45rem}.subtraction-bar-row{grid-template-columns:2.25rem minmax(0,1fr);gap:.3rem}.subtraction-compare-track{grid-template-columns:minmax(3rem,8fr) repeat(5,minmax(2.2rem,1fr));gap:0}.subtraction-shared-unit,.subtraction-extra-unit{border-width:1px;min-height:2.75rem}.subtraction-strategy-choice-buttons>button{text-align:center;grid-template-columns:1fr}.subtraction-strategy-choice-buttons>button>span{grid-row:auto}}@media (prefers-reduced-motion:reduce){.subtraction-strategy-stage *,.subtraction-strategy-stage :before,.subtraction-strategy-stage :after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important}}:root[data-theme=dark] .subtraction-strategy-stage{--subtraction-ink:#e7eefb;--subtraction-muted:#c5d1e5;--subtraction-border:#526482;--subtraction-panel:#172238;--subtraction-panel-strong:#1c2b47;background:radial-gradient(circle at 50% -20%,#273552 0 28%,#0000 64%),linear-gradient(145deg,#121a2b,#292233);border-color:#415371;box-shadow:0 20px 55px #0000004d,inset 0 1px #ffffff0f}:root[data-theme=dark] .subtraction-story-workspace{background:#0f172bb3}:root[data-theme=dark] .subtraction-story-whole-label{color:#e0e7ff;background:#312e81}:root[data-theme=dark] .subtraction-story-whole-label span{color:#c7d2fe}:root[data-theme=dark] .subtraction-story-eight,:root[data-theme=dark] .subtraction-story-five,:root[data-theme=dark] .subtraction-story-place-button,:root[data-theme=dark] .subtraction-story-return-zone{background:#172238}:root[data-theme=dark] .subtraction-story-away,:root[data-theme=dark] .subtraction-away-tray{background:#422006;border-color:#fb923c}:root[data-theme=dark] .subtraction-story-away.is-filled{background:#123c34;border-color:#34d399}:root[data-theme=dark] .subtraction-strategy-ten-frame{background:#111827;border-color:#818cf8}:root[data-theme=dark] .subtraction-strategy-ten-frame>i{background:#202b45;border-color:#6366f1}:root[data-theme=dark] .subtraction-action-hint{color:#e0e7ff;background:#312e81}:root[data-theme=dark] .subtraction-eight-stay-area{background:#0c4a6e;border-color:#38bdf8}:root[data-theme=dark] .subtraction-eight-stay-area>strong{color:#e0f2fe}:root[data-theme=dark] .subtraction-take-part{background:#4c1629;border-color:#fb7185}:root[data-theme=dark] .subtraction-take-part>strong{color:#fecdd3}:root[data-theme=dark] .subtraction-return-selected{color:#fecdd3;background:#172238;border-color:#fb7185}:root[data-theme=dark] .subtraction-away-slot{color:#fed7aa;background:#172238;border-color:#fb923c}:root[data-theme=dark] .subtraction-away-tray>small{color:#fed7aa}:root[data-theme=dark] .subtraction-next-landing{color:#ede9fe;background:#292447;border-color:#a78bfa}:root[data-theme=dark] .subtraction-next-marker{background:#111827;border-color:#c4b5fd}:root[data-theme=dark] .subtraction-next-marker i{background:#c4b5fd}:root[data-theme=dark] .subtraction-back-jump b{color:#fda4af}:root[data-theme=dark] .subtraction-strategy-action.is-secondary,:root[data-theme=dark] .subtraction-strategy-reset{color:#dbeafe;background:#1e293b}:root[data-theme=dark] .subtraction-bar-row>strong{color:#e0e7ff;background:#312e81}:root[data-theme=dark] .subtraction-shared-unit{color:#e0f2fe;background-color:#0c4a6e;border-color:#38bdf8}:root[data-theme=dark] .subtraction-extra-unit{color:#fed7aa;background:#422006;border-color:#fb923c}:root[data-theme=dark] .subtraction-extra-unit.is-counted,:root[data-theme=dark] .subtraction-strategy-feedback.is-success{color:#d1fae5;background:#064e3b;border-color:#34d399}:root[data-theme=dark] .subtraction-comparison-key i.is-shared{background:#0c4a6e;border-color:#38bdf8}:root[data-theme=dark] .subtraction-comparison-key i.is-extra{background:#422006;border-color:#fb923c}:root[data-theme=dark] :where(.subtraction-compact-model,.subtraction-equation-slot,.subtraction-explanation-slot,.subtraction-readiness-reminder>div,.subtraction-strategy-choice-buttons>button){background:#172238}:root[data-theme=dark] :where(.subtraction-equation-token,.subtraction-explanation-card){color:#e0e7ff;background:#202b45;border-color:#818cf8}:root[data-theme=dark] :where(.subtraction-equation-token,.subtraction-explanation-card).is-correct{color:#d1fae5;background:#064e3b;border-color:#34d399}:root[data-theme=dark] .subtraction-current-story{background:#252b52;border-color:#818cf8}:root[data-theme=dark] .subtraction-current-story small{color:#c7d2fe}:root[data-theme=dark] .subtraction-strategy-choice-buttons>button>span{color:#dbeafe;background:#1e3a5f}:root[data-theme=dark] .subtraction-strategy-choice-buttons>button.is-correct{background:#064e3b;border-color:#34d399}:root[data-theme=dark] .subtraction-place-selected{color:#ede9fe;background:#292447;border-color:#a78bfa}:root[data-theme=dark] .subtraction-place-selected:disabled{border-color:var(--subtraction-border);color:var(--subtraction-muted);background:var(--subtraction-panel-strong)}:root[data-theme=dark] .subtraction-compact-whole b{color:#e0f2fe;background:#0c4a6e}:root[data-theme=dark] .subtraction-compact-whole i,:root[data-theme=dark] .subtraction-compact-gap>i{color:#fed7aa;background:#422006;border-color:#fb923c}:root[data-theme=dark] .subtraction-readiness-reminder span{color:#bfdbfe}
.multiplication-stage{--multiplication-ink:#25324a;--multiplication-muted:#53627a;--multiplication-border:#b8c7df;--multiplication-panel:#f8fbff;--multiplication-panel-strong:#eef5ff;--multiplication-counter:#f973a5;--multiplication-counter-edge:#9f335d;--multiplication-accent:#5b4bdb;border:1px solid var(--multiplication-border);width:100%;min-width:0;max-width:100%;color:var(--multiplication-ink);text-align:center;overflow-wrap:anywhere;background:radial-gradient(circle at 50% -25%,#fff 0 28%,#0000 64%),linear-gradient(145deg,#eef7ff,#fff7ed);border-radius:clamp(1.2rem,3vw,2rem);justify-items:center;gap:clamp(1rem,2.5vw,1.45rem);padding:clamp(1rem,4vw,2.2rem);display:grid;overflow:hidden;box-shadow:0 18px 46px #2563eb1a,inset 0 1px #fff}.multiplication-stage *,.multiplication-stage :before,.multiplication-stage :after{box-sizing:border-box}.multiplication-stage>*{min-width:0;max-width:100%}.multiplication-stage-heading{gap:.35rem;width:min(100%,43rem);display:grid}.multiplication-stage-heading h3{color:var(--multiplication-ink);margin:0;font-size:clamp(1.45rem,4vw,2.1rem)}.multiplication-stage-heading>p:last-child{color:var(--multiplication-muted);margin:0;font-weight:700}.multiplication-counter{aspect-ratio:1;border:3px solid var(--multiplication-counter-edge);background:var(--multiplication-counter);border-radius:999px;width:clamp(2rem,7vw,2.75rem);display:inline-block;box-shadow:inset 0 4px #ffffff85,0 4px 8px #0f172a29}.multiplication-counter-group{grid-template-columns:repeat(2,minmax(2rem,2.75rem));justify-content:center;gap:clamp(.35rem,1.5vw,.55rem);display:grid}.multiplication-group-mat{border:2px solid var(--multiplication-border);min-width:0;color:var(--multiplication-ink);background:var(--multiplication-panel);border-radius:1.35rem;box-shadow:inset 0 -5px #4f46e514,0 8px 18px #0f172a12}.multiplication-see-workspace,.multiplication-build-workspace,.multiplication-count-groups,.multiplication-repeated-groups{grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(.65rem,2vw,1rem);width:min(100%,50rem);display:grid}.multiplication-notice-group,.multiplication-count-group{min-height:13rem;font:inherit;cursor:pointer;touch-action:manipulation;align-content:center;justify-items:center;gap:.75rem;padding:1rem .75rem;display:grid}.multiplication-notice-group:hover,.multiplication-count-group:hover{border-color:var(--multiplication-accent)}.multiplication-notice-group.is-noticed,.multiplication-count-group.is-counted{background:#ecfdf5;border-color:#12805c;box-shadow:inset 0 -5px #0596691f,0 0 0 3px #05966924}.multiplication-group-label{color:var(--multiplication-muted);letter-spacing:.04em;text-transform:uppercase;font-size:.85rem;font-weight:900}.multiplication-notice-group strong,.multiplication-count-group strong{min-height:2.4rem;color:var(--multiplication-ink)}.multiplication-feedback{color:#41328d;background:#f2efff;border:2px solid #7c6be5;border-radius:1rem;width:min(100%,43rem);min-height:3.1rem;margin:0;padding:.7rem .9rem;font-weight:800}.multiplication-feedback.is-complete{color:#065f46;background:#dff9ee;border-color:#12805c}.multiplication-reset,.multiplication-bank-return{color:#203c86;min-height:2.75rem;font:inherit;cursor:pointer;touch-action:manipulation;background:#fff;border:2px solid #3855a6;border-radius:.9rem;padding:.65rem 1rem;font-weight:850}.multiplication-bank-return:disabled{color:#52627a;cursor:not-allowed;background:#eef2f7;border-color:#9aa8bd}.multiplication-counter-bank,.multiplication-token-bank{background:var(--multiplication-panel-strong);border:2px dashed #8293b2;border-radius:1.2rem;gap:.7rem;width:min(100%,50rem);min-height:7rem;padding:.85rem;display:grid}.multiplication-counter-bank>div:first-child{flex-wrap:wrap;justify-content:space-between;gap:.4rem 1rem;display:flex}.multiplication-counter-bank>div:first-child span{color:var(--multiplication-muted);font-weight:800}.multiplication-bank-counters{grid-template-columns:repeat(12,minmax(2.75rem,1fr));gap:.3rem;display:grid}.multiplication-counter-button{cursor:grab;touch-action:manipulation;background:0 0;border:2px solid #0000;border-radius:.85rem;place-items:center;min-width:2.75rem;min-height:3.5rem;padding:.15rem;display:grid}.multiplication-counter-button .multiplication-counter{width:min(100%,2.55rem)}.multiplication-counter-button.is-selected{border-color:var(--multiplication-accent);background:#eeecff;box-shadow:0 0 0 3px #5b4bdb26}.multiplication-counter-button.is-last-moved:not(.is-selected){border-color:#12805c}.multiplication-build-group{align-content:start;gap:.75rem;padding:.85rem;display:grid}.multiplication-group-heading{flex-wrap:wrap;justify-content:space-between;gap:.35rem;display:flex}.multiplication-group-heading span{color:var(--multiplication-muted);font-weight:800}.multiplication-group-slots{grid-template-columns:repeat(2,minmax(3.1rem,1fr));gap:.45rem;display:grid}.multiplication-receiving-slot{cursor:pointer;touch-action:manipulation;background:#f7f5ff;border:2px dashed #7c6be5;border-radius:1rem;place-items:center;min-width:3.1rem;min-height:clamp(4rem,10vw,5.25rem);padding:.25rem;display:grid}.multiplication-receiving-slot.is-ready{background:#fff0f6;border-color:#d43171;box-shadow:inset 0 0 0 2px #d431711f}.multiplication-receiving-slot.is-filled{cursor:grab;background:#ecfdf5;border-style:solid;border-color:#12805c}.multiplication-receiving-slot .multiplication-counter{width:min(86%,2.75rem)}.multiplication-slot-cue{background:#fff;border:2px solid #7c6be5;border-radius:999px;width:1.1rem;height:1.1rem}.multiplication-count-workspace{gap:1rem;width:min(100%,50rem);display:grid}.multiplication-running-total{border:2px solid var(--multiplication-border);background:var(--multiplication-panel-strong);border-radius:1rem;justify-content:center;align-items:center;gap:clamp(.45rem,2vw,1rem);min-height:4.5rem;padding:.65rem;display:flex}.multiplication-running-total span{color:#68758a;align-items:center;gap:clamp(.45rem,2vw,1rem);font-size:clamp(1.25rem,5vw,2rem);font-weight:950;display:flex}.multiplication-running-total span.is-reached{color:#41328d}.multiplication-running-total i{color:#68758a;font-style:normal}.multiplication-repeated-workspace{justify-items:center;gap:1rem;width:min(100%,50rem);display:grid}.multiplication-repeated-groups>div{border:2px solid var(--multiplication-border);background:var(--multiplication-panel);border-radius:1.15rem;justify-items:center;gap:.55rem;padding:.75rem;display:grid}.multiplication-repeated-groups>div>span{color:var(--multiplication-muted);font-weight:850}.multiplication-repeated-groups .multiplication-counter{width:clamp(1.6rem,5.5vw,2.3rem)}.multiplication-token-bank>strong{color:var(--multiplication-ink)}.multiplication-token-bank>div{flex-wrap:wrap;justify-content:center;gap:.55rem;min-height:3.25rem;display:flex}.multiplication-value-token{border:2px solid var(--multiplication-accent);color:#35277f;min-width:3.25rem;min-height:3.25rem;font:inherit;cursor:grab;touch-action:manipulation;background:#f0edff;border-radius:.9rem;padding:.45rem .75rem;font-size:1.3rem;font-weight:950}.multiplication-value-token.is-selected{background:#fff0f6;border-color:#d43171;box-shadow:0 0 0 3px #d4317126}.multiplication-equation{justify-content:center;align-items:center;gap:clamp(.25rem,1vw,.55rem);width:100%;display:flex}.multiplication-equation-part{align-items:center;gap:clamp(.25rem,1vw,.55rem);min-width:0;display:flex}.multiplication-equation-part b{color:var(--multiplication-ink);font-size:clamp(1.3rem,5vw,2rem)}.multiplication-equation-slot{border:2px dashed var(--multiplication-accent);color:#35277f;width:clamp(3.15rem,13vw,4.75rem);min-width:3.15rem;min-height:clamp(3.5rem,13vw,4.75rem);font:inherit;cursor:pointer;touch-action:manipulation;background:#f7f5ff;border-radius:1rem;place-items:center;font-size:clamp(1.25rem,5vw,1.7rem);font-weight:950;display:grid}.multiplication-equation-slot.is-ready{background:#fff0f6;border-color:#d43171}.multiplication-equation-slot.is-filled{color:#065f46;cursor:grab;background:#ecfdf5;border-style:solid;border-color:#12805c}.multiplication-skip-workspace,.multiplication-array-workspace,.multiplication-connect-workspace{justify-items:center;gap:1rem;width:min(100%,52rem);display:grid}.multiplication-skip-groups{grid-template-columns:repeat(3,minmax(0,1fr));gap:.7rem;width:min(100%,42rem);display:grid}.multiplication-skip-groups>div{border:2px solid var(--multiplication-border);background:var(--multiplication-panel);border-radius:1rem;justify-items:center;gap:.45rem;min-width:0;padding:.65rem;display:grid}.multiplication-skip-groups>div.is-linked{background:#ecfdf5;border-color:#12805c}.multiplication-skip-groups span,.multiplication-skip-groups strong{color:var(--multiplication-muted);font-size:.8rem}.multiplication-skip-groups .multiplication-counter{width:clamp(1.3rem,4.5vw,2rem)}.multiplication-skip-groups .multiplication-counter-group{grid-template-columns:repeat(2,minmax(1.3rem,2rem));gap:.25rem}.multiplication-number-line{width:calc(100% - 2.5rem);min-height:9rem;margin-inline:1.25rem;padding-top:3.5rem;position:relative}.multiplication-line-track{background:#46546b;border-radius:999px;width:100%;height:.4rem;position:absolute;top:5.3rem;left:0}.multiplication-line-ticks{grid-template-columns:repeat(13,minmax(0,1fr));width:100%;display:grid;position:absolute;top:4.95rem;left:0;transform:translate(-.12rem)}.multiplication-line-ticks>span{justify-items:center;min-width:0;display:grid}.multiplication-line-ticks i{background:#46546b;width:.16rem;height:1rem}.multiplication-line-ticks b{color:var(--multiplication-ink);margin-top:.25rem;font-size:clamp(.62rem,2.2vw,.78rem)}.multiplication-line-ticks .is-reached b,.multiplication-line-ticks .is-current b{color:#fff;background:var(--multiplication-accent);border-radius:999px;place-items:center;min-width:1.65rem;min-height:1.65rem;margin-top:.12rem;display:grid}.multiplication-line-ticks .is-current b{background:#be185d;box-shadow:0 0 0 3px #be185d2b}.multiplication-jump-layer{z-index:2;width:100%;height:3.7rem;position:absolute;top:1rem;left:0}.multiplication-jump-layer>span{border:3px solid #be185d;border-bottom:0;border-radius:999px 999px 0 0;height:2.5rem;position:absolute;bottom:0}.multiplication-jump-layer b{color:#831843;background:#fff1f2;border:2px solid #be185d;border-radius:.55rem;padding:.2rem .4rem;font-size:.75rem;position:absolute;top:-1.15rem;left:50%;transform:translate(-50%)}.multiplication-skip-controls{flex-wrap:wrap;justify-content:center;gap:.55rem;display:flex}.multiplication-action{color:#fff;min-height:2.75rem;font:inherit;cursor:pointer;touch-action:manipulation;background:#5145cd;border:2px solid #4338ca;border-radius:.9rem;padding:.65rem 1rem;font-weight:850}.multiplication-action:disabled,.multiplication-reset:disabled{color:#52627a;cursor:not-allowed;background:#eef2f7;border-color:#9aa8bd}.multiplication-array-workspace{grid-template-columns:minmax(13rem,.72fr) minmax(19rem,1.28fr);align-items:stretch}.multiplication-array-source,.multiplication-array-board{border:2px solid var(--multiplication-border);background:var(--multiplication-panel-strong);border-radius:1.25rem;align-content:start;gap:.65rem;width:100%;min-width:0;padding:.8rem;display:grid}.multiplication-array-source-group{border:2px solid var(--multiplication-border);min-height:5.5rem;color:var(--multiplication-ink);background:var(--multiplication-panel);font:inherit;cursor:grab;touch-action:manipulation;border-radius:1rem;grid-template-columns:minmax(4.5rem,auto) 1fr;align-items:center;gap:.55rem;padding:.55rem;display:grid}.multiplication-array-source-group>span{color:var(--multiplication-muted);font-weight:850}.multiplication-array-source-group .multiplication-counter{width:min(100%,1.75rem)}.multiplication-array-source-group .multiplication-counter-group{grid-template-columns:repeat(4,minmax(1.35rem,1.75rem));gap:.18rem}.multiplication-array-source-group.is-selected{background:#fff1f2;border-color:#be185d;box-shadow:0 0 0 3px #be185d24}.multiplication-array-source-group.is-moved{background:#ecfdf5;border-color:#12805c}.multiplication-column-labels{color:var(--multiplication-muted);grid-template-columns:minmax(3.5rem,.5fr) repeat(4,minmax(2.75rem,1fr));align-items:center;gap:.35rem;font-size:.76rem;font-weight:850;display:grid}.multiplication-array-row{border:2px dashed var(--multiplication-accent);min-height:5rem;color:var(--multiplication-ink);font:inherit;cursor:pointer;touch-action:manipulation;background:#f7f5ff;border-radius:1rem;grid-template-columns:minmax(3.5rem,.5fr) 4fr;align-items:center;gap:.35rem;padding:.4rem;display:grid}.multiplication-array-row.is-ready{background:#fff1f2;border-color:#be185d}.multiplication-array-row.is-filled{cursor:grab;background:#ecfdf5;border-style:solid;border-color:#12805c}.multiplication-array-row>strong{font-size:.78rem}.multiplication-array-cells{grid-template-columns:repeat(4,minmax(2.75rem,1fr));gap:.35rem;display:grid}.multiplication-array-cells>i{background:var(--multiplication-panel);border:2px solid #8d82da;border-radius:.8rem;place-items:center;min-width:2.75rem;min-height:3.75rem;display:grid}.multiplication-array-cells .multiplication-counter{width:min(82%,2.55rem)}.multiplication-connect-models{border:2px solid var(--multiplication-border);background:var(--multiplication-panel);border-radius:1.15rem;grid-template-columns:minmax(12rem,1fr) minmax(12rem,1fr);align-items:center;gap:.75rem;width:min(100%,38rem);padding:.75rem;display:grid}.multiplication-connect-models>strong{color:#41328d;background:#f2efff;border-radius:.85rem;padding:.75rem;font-size:clamp(1.2rem,5vw,1.75rem)}.multiplication-mini-array{border:2px solid var(--multiplication-accent);background:var(--multiplication-panel-strong);border-radius:.9rem;gap:.3rem;padding:.55rem;display:grid}.multiplication-mini-array>span{grid-template-columns:repeat(4,minmax(1.45rem,2rem));justify-content:center;gap:.25rem;display:grid}.multiplication-mini-array .multiplication-counter{width:min(100%,2rem)}.multiplication-symbol-token-bank{border:2px dashed var(--multiplication-border);background:var(--multiplication-panel-strong);border-radius:1rem;gap:.65rem;width:min(100%,44rem);padding:.75rem;display:grid}.multiplication-symbol-token-bank>div{flex-wrap:wrap;justify-content:center;gap:.5rem;min-height:3.4rem;display:flex}.multiplication-symbol-token{border:2px solid var(--multiplication-accent);color:#35277f;min-width:3.4rem;min-height:3.4rem;font:inherit;cursor:grab;touch-action:manipulation;background:#f0edff;border-radius:.85rem;padding:.45rem .7rem;font-size:1.35rem;font-weight:950}.multiplication-symbol-token.is-selected{background:#fff1f2;border-color:#be185d;box-shadow:0 0 0 3px #be185d24}.multiplication-sentence-builder{grid-template-columns:repeat(5,minmax(0,1fr));gap:.45rem;width:100%;display:grid}.multiplication-role-slot{border:2px dashed var(--multiplication-accent);min-width:0;min-height:7.5rem;color:var(--multiplication-ink);font:inherit;cursor:pointer;touch-action:manipulation;background:#f7f5ff;border-radius:1rem;align-content:center;justify-items:center;gap:.35rem;padding:.5rem;display:grid}.multiplication-role-slot>span{color:var(--multiplication-muted);font-size:clamp(.68rem,2vw,.8rem);font-weight:800}.multiplication-role-slot>strong{font-size:clamp(1.25rem,5vw,1.8rem)}.multiplication-role-slot.is-ready{background:#fff1f2;border-color:#be185d}.multiplication-role-slot.is-filled{cursor:grab;background:#ecfdf5;border-style:solid;border-color:#12805c}.multiplication-ready-stage{gap:.8rem;padding-block:clamp(.9rem,3vw,1.5rem)}.multiplication-ready-strip{grid-template-columns:repeat(4,minmax(0,1fr));gap:.55rem;width:min(100%,52rem);display:grid}.multiplication-ready-strip>div{border:2px solid var(--multiplication-border);background:var(--multiplication-panel);border-radius:1rem;align-content:center;justify-items:center;gap:.35rem;min-height:7.5rem;padding:.6rem;display:grid}.multiplication-ready-strip>div>span,.multiplication-ready-strip em{color:var(--multiplication-muted);font-size:.75rem;font-style:normal;font-weight:800}.multiplication-ready-strip .multiplication-counter{width:min(100%,1.55rem)}.multiplication-ready-strip .multiplication-counter-group{grid-template-columns:repeat(2,minmax(1.3rem,1.55rem));gap:.18rem}.multiplication-ready-array>span{grid-template-columns:repeat(4,.65rem);gap:.12rem;display:grid}.multiplication-ready-array>span>i{aspect-ratio:1;border:1px solid var(--multiplication-counter-edge);background:var(--multiplication-counter);border-radius:999px;width:.65rem}.multiplication-stage :where(button,[tabindex="0"]):focus-visible{outline-offset:3px;outline:4px solid #f59e0b}:root[data-theme=dark] .multiplication-stage{--multiplication-ink:#f4f7ff;--multiplication-muted:#d2dced;--multiplication-border:#61708a;--multiplication-panel:#172238;--multiplication-panel-strong:#202d46;--multiplication-counter:#fb8db6;--multiplication-counter-edge:#ffd1e2;color:var(--multiplication-ink);background:radial-gradient(circle at 50% -25%,#253553 0 28%,#0000 64%),linear-gradient(145deg,#111b2f,#282038);box-shadow:0 18px 46px #00000047,inset 0 1px #ffffff14}:root[data-theme=dark] .multiplication-notice-group.is-noticed,:root[data-theme=dark] .multiplication-count-group.is-counted,:root[data-theme=dark] .multiplication-receiving-slot.is-filled,:root[data-theme=dark] .multiplication-equation-slot.is-filled{color:#eafff7;background:#14392f;border-color:#5ee6b5}:root[data-theme=dark] .multiplication-feedback{color:#f2efff;background:#302b58;border-color:#a99cff}:root[data-theme=dark] .multiplication-feedback.is-complete{color:#eafff7;background:#14392f;border-color:#5ee6b5}:root[data-theme=dark] .multiplication-reset,:root[data-theme=dark] .multiplication-bank-return{color:#f4f7ff;background:#202d46;border-color:#9bb3ff}:root[data-theme=dark] .multiplication-bank-return:disabled{color:#d2dced;background:#172238;border-color:#61708a}:root[data-theme=dark] .multiplication-receiving-slot,:root[data-theme=dark] .multiplication-equation-slot{color:#f4f7ff;background:#28254d}:root[data-theme=dark] .multiplication-receiving-slot.is-ready,:root[data-theme=dark] .multiplication-equation-slot.is-ready,:root[data-theme=dark] .multiplication-counter-button.is-selected,:root[data-theme=dark] .multiplication-value-token.is-selected{color:#fff1f6;background:#4b233a}:root[data-theme=dark] .multiplication-value-token{color:#f4f1ff;background:#302b58;border-color:#a99cff}:root[data-theme=dark] .multiplication-slot-cue{background:#202d46}:root[data-theme=dark] .multiplication-running-total span{color:#b8c4d8}:root[data-theme=dark] .multiplication-running-total span.is-reached{color:#ddd7ff}:root[data-theme=dark] .multiplication-skip-groups>div.is-linked,:root[data-theme=dark] .multiplication-array-source-group.is-moved,:root[data-theme=dark] .multiplication-array-row.is-filled,:root[data-theme=dark] .multiplication-role-slot.is-filled{color:#eafff7;background:#14392f;border-color:#5ee6b5}:root[data-theme=dark] .multiplication-action{background:#5145cd;border-color:#a99cff}:root[data-theme=dark] .multiplication-action:disabled,:root[data-theme=dark] .multiplication-reset:disabled{color:#d2dced;background:#172238;border-color:#61708a}:root[data-theme=dark] .multiplication-jump-layer b{color:#fff1f6;background:#4b233a;border-color:#fb8db6}:root[data-theme=dark] .multiplication-array-source-group.is-selected,:root[data-theme=dark] .multiplication-array-row.is-ready,:root[data-theme=dark] .multiplication-symbol-token.is-selected,:root[data-theme=dark] .multiplication-role-slot.is-ready{color:#fff1f6;background:#4b233a}:root[data-theme=dark] .multiplication-array-row,:root[data-theme=dark] .multiplication-array-cells>i,:root[data-theme=dark] .multiplication-role-slot{color:#f4f7ff;background:#28254d}:root[data-theme=dark] .multiplication-connect-models>strong{color:#f2efff;background:#302b58}:root[data-theme=dark] .multiplication-symbol-token{color:#f4f1ff;background:#302b58;border-color:#a99cff}@media (max-width:760px){.multiplication-bank-counters{grid-template-columns:repeat(6,minmax(2.75rem,1fr))}.multiplication-build-workspace,.multiplication-array-workspace{grid-template-columns:1fr}.multiplication-build-group{width:100%}.multiplication-group-slots{grid-template-columns:repeat(4,minmax(3rem,1fr))}}@media (max-width:600px){.multiplication-stage{padding:.9rem}.multiplication-see-workspace,.multiplication-count-groups{grid-template-columns:1fr}.multiplication-notice-group,.multiplication-count-group{text-align:left;grid-template-rows:auto auto;grid-template-columns:minmax(6.5rem,auto) 1fr;min-height:0}.multiplication-notice-group .multiplication-group-label,.multiplication-count-group .multiplication-group-label{grid-column:1/-1}.multiplication-notice-group strong,.multiplication-count-group strong{align-self:center}.multiplication-repeated-groups{gap:.4rem}.multiplication-repeated-groups>div{padding:.55rem .25rem}.multiplication-repeated-groups .multiplication-counter-group{grid-template-columns:repeat(2,minmax(1.45rem,1.9rem));gap:.25rem}.multiplication-repeated-groups .multiplication-counter{width:min(100%,1.9rem)}.multiplication-sentence-builder{grid-template-columns:repeat(3,minmax(0,1fr))}.multiplication-role-slot{min-height:6.4rem}.multiplication-ready-strip{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (max-width:390px){.multiplication-bank-counters{grid-template-columns:repeat(4,minmax(2.75rem,1fr))}.multiplication-group-slots{grid-template-columns:repeat(2,minmax(3.1rem,1fr))}.multiplication-equation,.multiplication-equation-part{gap:.15rem}.multiplication-equation-slot{width:3.15rem;min-width:3.15rem}.multiplication-skip-groups{gap:.3rem}.multiplication-skip-groups>div{padding:.45rem .2rem}.multiplication-line-ticks b{font-size:.58rem}.multiplication-column-labels{grid-template-columns:3.1rem repeat(4,minmax(2.75rem,1fr))}.multiplication-array-row{grid-template-columns:3.1rem 4fr}.multiplication-array-board{padding:.5rem}.multiplication-array-cells{gap:.18rem}.multiplication-connect-models{grid-template-columns:1fr}.multiplication-sentence-builder{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (prefers-reduced-motion:reduce){.multiplication-stage *,.multiplication-stage :before,.multiplication-stage :after{scroll-behavior:auto;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}
.division-stage{--division-ink:#17324d;--division-muted:#4b6075;--division-panel:#f7fbff;--division-panel-strong:#e7f4ff;--division-border:#8fc6e8;--division-slot:#fff;--division-counter:#ffd166;--division-counter-edge:#b87317;width:100%;min-width:0;max-width:100%;color:var(--division-ink);overflow-wrap:anywhere}.division-stage-heading{gap:.35rem;margin-bottom:1.15rem;display:grid}.division-stage-heading p,.division-stage-heading h3,.division-stage-heading span,.division-zone-heading strong,.division-zone-heading span,.division-whole-label strong,.division-whole-label span{margin:0}.division-stage-heading p{color:#166087;letter-spacing:.08em;text-transform:uppercase;font-size:.78rem;font-weight:800}.division-stage-heading h3{font-size:clamp(1.35rem,3vw,1.9rem);line-height:1.15}.division-stage-heading span,.division-keyboard-help{color:var(--division-muted);line-height:1.55}.division-whole-workspace,.division-counter-bank,.division-share-tray,.division-group-card{border:2px solid var(--division-border);background:var(--division-panel);min-width:0;box-shadow:0 8px 20px #1e55781a}.division-whole-workspace{border-radius:1.5rem;padding:clamp(.85rem,3vw,1.4rem)}.division-whole-label,.division-zone-heading{justify-content:space-between;align-items:center;gap:.65rem;margin-bottom:.75rem;display:flex}.division-whole-label span,.division-zone-heading span{color:var(--division-muted);font-size:.88rem;font-weight:700}.division-whole-model{background:var(--division-panel-strong);border-radius:1.25rem;justify-content:center;align-items:center;gap:clamp(.7rem,3vw,1.25rem);padding:.8rem;display:flex}.division-ten-frame{background:var(--division-slot);border:3px solid #397ea8;border-radius:1rem;grid-template-columns:repeat(5,minmax(2.75rem,3.4rem));gap:.42rem;padding:.5rem;display:grid}.division-extra-two{grid-template-columns:repeat(2,2.9rem);gap:.5rem;display:grid}.division-counter,.division-counter-space,.division-movable-counter,.division-receiving-slot,.division-ten-frame>button,.division-extra-two>button{width:2.75rem;min-width:2.75rem;height:2.75rem;min-height:2.75rem}.division-ten-frame>button,.division-extra-two>button,.division-movable-counter,.division-receiving-slot{touch-action:manipulation;cursor:pointer;background:0 0;border:0;border-radius:50%;place-items:center;padding:0;display:inline-grid}.division-counter{border:3px solid var(--division-counter-edge);background:var(--division-counter);border-radius:50%;place-items:center;display:inline-grid;position:relative;box-shadow:inset 0 4px #ffffff8c,0 3px #8a5311}.division-counter i{background:#ffffff80;border-radius:50%;width:.75rem;height:.75rem}.division-counter b{color:#fff;background:#185f91;border:2px solid #fff;border-radius:50%;place-items:center;width:1.35rem;height:1.35rem;font-size:.72rem;display:grid;position:absolute;inset:auto -.25rem -.3rem auto}.division-counter.is-counted{border-color:#287858}.division-controls{flex-wrap:wrap;justify-content:center;gap:.65rem;margin-top:1rem;display:flex}.division-action,.division-secondary-action{touch-action:manipulation;border:2px solid #17678f;border-radius:999px;min-height:2.75rem;padding:.65rem 1rem;font-weight:800}.division-action{color:#fff;background:#17678f}.division-action:disabled{color:#5c6770;cursor:not-allowed;background:#e4eaee;border-color:#9aa9b4}.division-secondary-action{color:#164f71;background:#fff}.division-share-workspace,.division-grouping-workspace{gap:1rem;min-width:0;display:grid}.division-counter-bank{border-radius:1.35rem;padding:.85rem}.division-bank-grid{grid-template-columns:repeat(6,minmax(2.75rem,1fr));justify-items:center;gap:.45rem;display:grid}.division-counter-space{background:#ffffff8c;border:2px dashed #aac4d4;border-radius:50%;display:block}.division-share-arrow,.division-group-flow{color:#17678f;justify-self:center;font-weight:850}.division-trays,.division-group-list{grid-template-columns:repeat(3,minmax(0,1fr));gap:.75rem;min-width:0;display:grid}.division-share-tray,.division-group-card{border-radius:1.25rem;padding:.7rem}.division-tray-slots,.division-group-slots{grid-template-columns:repeat(2,2.75rem);justify-content:center;gap:.5rem;display:grid}.division-receiving-slot{background:var(--division-slot);border:2px dashed #4384aa}.division-receiving-slot.is-ready,.division-share-tray.is-ready,.division-group-card.is-active{border-color:#7b52b9;box-shadow:0 0 0 3px #7b52b92e}.division-receiving-slot.is-filled{border-style:solid}.division-tray-overflow{flex-wrap:wrap;justify-content:center;gap:.35rem;margin-top:.55rem;display:flex}.division-group-card.is-complete{background:#eefaf4;border-color:#4a9872}.division-movable-counter.is-selected,.division-receiving-slot[aria-pressed=true]{outline-offset:3px;border-radius:50%;outline:4px solid #7b52b9}.division-movable-counter.is-last-moved .division-counter{box-shadow:inset 0 4px #ffffff8c,0 0 0 4px #277e5940,0 3px #8a5311}.division-feedback{color:var(--division-ink);background:#edf7fd;border-left:5px solid #4c89ae;border-radius:.75rem;margin:1rem 0 0;padding:.85rem 1rem;font-weight:750;line-height:1.5}.division-feedback.is-success{background:#e9f8f0;border-color:#2c815e}.division-feedback.is-try{background:#fff5dd;border-color:#b8751b}.division-keyboard-help{text-align:center;margin:0;font-size:.9rem}.division-sr-announcement{clip-path:inset(50%);white-space:nowrap;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.division-count-groups-workspace,.division-multiplication-workspace,.division-connect-workspace{border:2px solid var(--division-border);background:var(--division-panel);border-radius:1.5rem;gap:1rem;min-width:0;padding:clamp(.8rem,3vw,1.25rem);display:grid}.division-meaning-note{color:var(--division-ink);background:var(--division-panel-strong);text-align:center;border-radius:.85rem;margin:0;padding:.75rem .9rem;line-height:1.5}.division-static-groups,.division-countable-groups{grid-template-columns:repeat(3,minmax(0,1fr));gap:.75rem;min-width:0;display:grid}.division-static-group,.division-countable-group{border:2px solid var(--division-border);min-width:0;color:var(--division-ink);background:var(--division-slot);border-radius:1.1rem;justify-items:center;gap:.55rem;padding:.75rem .55rem;display:grid}.division-static-group>div,.division-countable-group>div{grid-template-columns:repeat(2,2.75rem);gap:.35rem;display:grid}.division-static-group>span,.division-countable-group>span,.division-static-group>strong,.division-countable-group>strong{text-align:center;line-height:1.25}.division-countable-group{touch-action:manipulation;cursor:pointer;min-height:10rem}.division-countable-group.is-counted{border-color:#2c815e;box-shadow:0 0 0 3px #2c815e2e}.division-result-space{background:var(--division-slot);border:2px dashed #4384aa;border-radius:1rem;justify-content:center;align-items:center;gap:.75rem;width:min(100%,20rem);min-height:4.25rem;margin-inline:auto;padding:.75rem 1rem;display:flex}.division-result-space strong{background:var(--division-panel-strong);border-radius:.65rem;padding:.35rem .65rem}.division-equation-builder{gap:.8rem;min-width:0;display:grid}.division-token-bank{border:2px solid var(--division-border);background:var(--division-panel-strong);border-radius:1rem;gap:.55rem;padding:.7rem;display:grid}.division-token-bank>span{color:var(--division-muted);text-align:center;font-size:.85rem;font-weight:800}.division-token-bank>div{grid-template-columns:repeat(5,minmax(2.75rem,1fr));justify-items:center;gap:.5rem;display:grid}.division-equation-token,.division-equation-token-space{border-radius:.8rem;place-items:center;width:3rem;min-width:2.75rem;height:3rem;min-height:2.75rem;display:inline-grid}.division-equation-token{color:#163d57;touch-action:manipulation;cursor:pointer;background:#fff;border:2px solid #317aa4;font-size:1.2rem;font-weight:900;box-shadow:0 3px #235d7d}.division-equation-token-space{background:var(--division-slot);border:2px dashed #a9c4d5}.division-equation-token.is-selected{outline-offset:3px;outline:4px solid #7b52b9}.division-equation-roles{grid-template-columns:repeat(5,minmax(4.75rem,1fr));gap:.45rem;min-width:0;display:grid}.division-equation-role{min-width:0;min-height:6rem;color:var(--division-ink);background:var(--division-slot);touch-action:manipulation;cursor:pointer;border:2px dashed #4384aa;border-radius:.9rem;align-content:space-between;justify-items:center;gap:.5rem;padding:.55rem .35rem;display:grid}.division-equation-role>span{text-align:center;font-size:.72rem;font-weight:750;line-height:1.2}.division-equation-role>strong{color:#163d57;background:#fff;border-radius:.7rem;place-items:center;width:2.75rem;min-height:2.75rem;font-size:1.2rem;display:grid}.division-equation-role.is-filled{border-style:solid}.division-equation-role.is-ready{border-color:#7b52b9;box-shadow:0 0 0 3px #7b52b92e}.division-story-switch{grid-template-columns:repeat(2,minmax(0,1fr));gap:.65rem;display:grid}.division-story-switch button{border:2px solid var(--division-border);min-height:2.75rem;color:var(--division-ink);background:var(--division-slot);touch-action:manipulation;border-radius:.85rem;padding:.65rem;font-weight:800}.division-story-switch button.is-current{border-color:#7b52b9;box-shadow:0 0 0 3px #7b52b92e}.division-story-switch button:disabled{color:var(--division-muted);cursor:not-allowed;border-style:dashed}.division-ready-strip{grid-template-columns:repeat(3,minmax(0,1fr));gap:.75rem;display:grid}.division-ready-strip article{border:2px solid var(--division-border);min-width:0;color:var(--division-ink);background:var(--division-panel);border-radius:1rem;align-content:start;gap:.5rem;padding:.8rem;display:grid}.division-ready-strip article>span{color:var(--division-muted);line-height:1.4}.division-ready-strip article>div{background:var(--division-panel-strong);border-radius:.7rem;justify-content:space-between;align-items:center;gap:.5rem;margin-top:auto;padding:.55rem;display:flex}.division-ready-strip i,.division-ready-strip b{font-style:normal}.division-stage button:focus-visible,.division-group-card:focus-visible{outline-offset:4px;outline:4px solid #6d43ad}:root[data-theme=dark] .division-stage{--division-ink:#f2f7fb;--division-muted:#c7d6e2;--division-panel:#172d3d;--division-panel-strong:#203e52;--division-border:#5fa4cc;--division-slot:#102737;--division-counter:#ffd166;--division-counter-edge:#f3a936}:root[data-theme=dark] .division-stage-heading p,:root[data-theme=dark] .division-share-arrow,:root[data-theme=dark] .division-group-flow{color:#8ed7ff}:root[data-theme=dark] .division-secondary-action{color:#eaf7ff;background:#17384c}:root[data-theme=dark] .division-equation-token,:root[data-theme=dark] .division-equation-role>strong{color:#f2f7fb;background:#17384c}:root[data-theme=dark] .division-countable-group.is-counted{border-color:#69c59b}:root[data-theme=dark] .division-group-card.is-complete,:root[data-theme=dark] .division-feedback.is-success{background:#173c30}:root[data-theme=dark] .division-feedback,:root[data-theme=dark] .division-feedback.is-try{color:#f2f7fb;background:#243c4d}@media (max-width:760px){.division-bank-grid{grid-template-columns:repeat(4,minmax(2.75rem,1fr))}.division-whole-model{flex-direction:column}.division-ten-frame{grid-template-columns:repeat(5,2.75rem)}.division-equation-roles{grid-template-columns:repeat(5,minmax(0,1fr))}}@media (max-width:480px){.division-trays,.division-group-list,.division-static-groups,.division-countable-groups,.division-ready-strip{grid-template-columns:1fr}.division-share-tray,.division-group-card{width:100%}.division-whole-model{padding-inline:.25rem}.division-ten-frame{gap:.2rem;padding:.3rem}.division-controls>button{width:100%}.division-equation-role{min-height:6.5rem;padding-inline:.15rem}.division-equation-role>span{font-size:.66rem}.division-story-switch{grid-template-columns:1fr}}@media (prefers-reduced-motion:reduce){.division-stage *,.division-stage :before,.division-stage :after{scroll-behavior:auto;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}
