@font-face{font-family:Nunito;font-style:normal;font-display:swap;font-weight:400;src:url(/assets/nunito-latin-400-normal-r8SDr6Up.woff2) format("woff2"),url(/assets/nunito-latin-400-normal-DKg4f3fz.woff) format("woff")}@font-face{font-family:Nunito;font-style:normal;font-display:swap;font-weight:700;src:url(/assets/nunito-latin-700-normal-Dort48En.woff2) format("woff2"),url(/assets/nunito-latin-700-normal-OcDqTBcA.woff) format("woff")}@font-face{font-family:Nunito;font-style:normal;font-display:swap;font-weight:800;src:url(/assets/nunito-latin-800-normal-Dz8SOQK_.woff2) format("woff2"),url(/assets/nunito-latin-800-normal-D-J0wlBY.woff) format("woff")}:root{font-family:Nunito,system-ui,sans-serif;color:#24324a;background:#fff9ef;font-synthesis:none;--ink: #24324a;--muted: #566178;--yellow: #f6c84a;--coral: #f27474;--sky: #73b8f2;--teal: #45b8a4;--green: #73c98b;--violet: #8d78d7}*{box-sizing:border-box}body{margin:0}button,input,select{font:inherit}button{min-height:48px;min-width:48px;border:2px solid transparent;border-radius:16px;background:#edf4fb;color:var(--ink);padding:12px 20px;font-weight:800;font-size:18px;cursor:pointer}button:hover{border-color:var(--ink)}button:disabled{opacity:.55;cursor:default}button:focus-visible,input:focus-visible,select:focus-visible,canvas:focus-visible{outline:3px solid #4b3998;outline-offset:4px}.primary{background:var(--yellow);box-shadow:0 4px #c6a031}.quiet{background:#fff;border-color:#d8dfeb}.danger{background:#fff0ee;border-color:#d38b83}input,select{min-height:52px;border:2px solid #8290a7;border-radius:12px;padding:10px 14px;background:#fff;width:100%}h1{font-size:clamp(28px,4vw,42px);line-height:1.15;margin:12px 0 20px;font-weight:800}h2{font-size:26px;margin:0 0 16px}p{font-size:20px;line-height:1.5;margin:12px 0}small,.muted{color:var(--muted)}small{font-size:16px}.shell{max-width:1080px;margin:auto;padding:24px 32px 40px;min-height:100dvh}.header{display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;padding-bottom:24px}.brand{font-weight:800;font-size:20px;display:flex;gap:10px;align-items:center}.brand-mark{display:grid;place-items:center;background:var(--yellow);border-radius:14px;width:48px;height:48px;font-size:24px}.profile-pill{background:#eee7fc;border-radius:999px;padding:8px 18px;font-weight:800}.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.stack{display:grid;gap:20px}.card{background:#fff;border:2px solid #e7e4de;border-radius:28px;padding:28px}.hero{background:linear-gradient(120deg,#fff0b3,#fff8e7);border-color:#edd18b}.eyebrow{font-size:15px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:#566178}.profile-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px;margin:24px 0}.profile-card{padding:24px;min-height:140px;background:#f2ecff;border-color:#b4a2db;font-size:24px}.profile-card:nth-child(2n){background:#e4f3ff;border-color:#92bddc}.avatar{display:block;font-size:36px;margin-bottom:8px}.home-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:24px}.block-tile{width:100%;background:#e5f5ee;text-align:left;padding:24px;margin-top:16px;font-size:26px}.coach{display:flex;gap:20px;align-items:center;background:#fff6df;border-radius:20px;padding:16px 20px}.fox{width:82px;height:82px;flex-shrink:0}.coach p{margin:0;font-size:20px}.exercise-card{max-width:820px;margin:auto;text-align:center}.equation{font-size:clamp(32px,5vw,48px);font-weight:800;letter-spacing:3px;margin:20px 0}.frame{display:grid;grid-template-columns:repeat(5,minmax(48px,1fr));gap:8px;padding:12px;border:3px solid #4d83af;border-radius:24px;background:#e8f4fd;max-width:620px;margin:24px auto}.slot{aspect-ratio:1;min-height:64px;padding:8px;background:#fff;border:2px solid #91aec8;border-radius:12px;position:relative;display:block;-webkit-appearance:none;appearance:none}.slot>.counter,.slot>.empty-ring{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);margin:0}.slot:disabled{opacity:1}.counter{display:block;width:clamp(30px,5vw,58px);height:clamp(30px,5vw,58px);aspect-ratio:1;border-radius:50%;background:var(--coral);border:3px solid #bd4c4c;box-shadow:inset 0 -4px #00000010}.counter.added{background:var(--sky);border-color:#36729e}.tray{justify-content:center;background:#f3f7fb;padding:12px;border-radius:20px;margin:20px auto;touch-action:none;max-width:620px}.tray button{background:#fff}.controls{justify-content:center;margin-top:24px}.feedback{border:2px solid #419260;background:#eef8ee;border-radius:20px;padding:20px;margin-top:24px}.feedback.retry{background:#fff6df;border-color:#c4a044}.error{background:#fff0ee;color:#842c29;border:2px solid #d79a91;border-radius:12px;padding:12px;font-size:18px}.notice{background:#e9f3fd;border-radius:12px;padding:12px;font-size:18px}.learning-help{margin:24px auto 0;max-width:440px;text-align:left}.learning-help summary{min-height:48px;display:list-item;padding:12px;color:var(--ink);font-weight:700;cursor:pointer}.learning-help summary:focus-visible{outline:3px solid #4b3998;outline-offset:4px}.writing-pad{touch-action:none;width:min(100%,440px);height:240px;background:#fffef9;border:3px dashed #8d78b3;border-radius:24px;display:block;margin:20px auto}.choices{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;max-width:440px;margin:auto}.choices button{font-size:32px}.selected{border-color:#24324a!important;background:#dcefee!important}.adult table{width:100%;border-collapse:collapse;font-size:18px}.adult th,.adult td{padding:14px 8px;text-align:left;border-bottom:1px solid #d9dfe6}.adult .card{overflow-x:auto}.file-label{display:block;padding:16px;background:#edf4fb;border:2px dashed #8290a7;border-radius:16px}.file-label input{margin-top:12px}.footer{margin-top:32px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}.sr-only{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.drag-ghost{position:fixed;pointer-events:none;z-index:20;transform:translate(-50%,-50%)}.form{max-width:520px}.form label{display:block;font-size:18px;font-weight:700;margin:12px 0 8px}.step-label{font-size:16px;color:#566178}.empty-ring{border:2px dashed #91aec8;border-radius:50%;width:70%;height:70%;aspect-ratio:1}.checkmark{font-size:28px}.progress-list{display:grid;gap:12px}.progress-item{padding:14px;background:#f5f7fa;border-radius:12px}.adult p{font-size:18px}.badge{display:inline-block;background:#e5f5ee;border-radius:12px;padding:6px 12px;font-size:16px}@media(max-width:650px){.shell{padding:16px}.home-grid{grid-template-columns:1fr}.card{padding:20px}.frame{gap:4px;padding:8px}.slot{min-height:48px;padding:4px}.coach{gap:12px;padding:12px}.fox{width:60px;height:60px}.header{padding-bottom:16px}.adult th,.adult td{font-size:16px}.row button{flex-grow:1}}.shell-exercise{padding:12px 16px 16px}.shell-exercise .header{padding-bottom:8px;gap:8px}.shell-exercise .brand{font-size:18px}.shell-exercise .brand-mark{width:40px;height:40px;font-size:22px}.shell-exercise .profile-pill{padding:6px 12px;max-width:18ch;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.shell-exercise .header button{padding:8px 14px}.shell-exercise .step-label{max-width:900px;margin:0 auto 6px;font-size:14px}.exercise-card{display:grid;gap:10px;padding:16px;max-width:900px}.exercise-heading .eyebrow{font-size:12px}.exercise-heading .equation{font-size:clamp(36px,5vw,46px);margin:2px 0;line-height:1.2}.exercise-heading h1{font-size:24px;margin:4px 0}.exercise-heading p{font-size:17px;line-height:1.3;margin:4px 0 0}.exercise-card .coach{padding:8px 12px;gap:12px}.exercise-card .fox{width:48px;height:48px}.exercise-card .coach p{font-size:16px;line-height:1.35}.exercise-card .frame{--slot-size: clamp(48px, 8vw, 72px);grid-template-columns:repeat(5,var(--slot-size));grid-auto-rows:var(--slot-size);width:max-content;margin:0 auto;padding:10px}.exercise-card .slot{width:var(--slot-size);height:var(--slot-size);min-height:48px;padding:0}.exercise-card .counter{width:clamp(30px,4.6vw,44px);height:clamp(30px,4.6vw,44px)}.exercise-card .tray{display:grid;grid-template-columns:56px minmax(0,1fr) auto;gap:8px;width:100%;max-width:440px;padding:8px;margin:0 auto}.exercise-card .tray button{padding:6px 10px;font-size:16px}.exercise-card .tray .counter{width:32px;height:32px}.exercise-card .tray>span{font-size:15px;line-height:1.3}.exercise-card .controls{margin-top:8px;gap:8px}.exercise-actions{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));width:100%;max-width:440px;margin:0 auto!important}.exercise-card button{overflow-wrap:anywhere}.exercise-card .learning-help{margin:0 auto;width:100%}.exercise-card .feedback{margin:0;padding:12px}.exercise-card .feedback h2{margin-bottom:4px}.exercise-card .feedback p{margin:4px 0}.exercise-card.is-feedback .coach,.exercise-card.is-feedback .tray{display:none}.handwriting h2{font-size:22px;margin:0 0 4px}.handwriting>small{display:block;max-width:620px;margin:auto;font-size:15px;line-height:1.3}.handwriting .writing-pad{height:clamp(150px,24vh,220px);margin:10px auto}.handwriting .notice{margin:8px auto 0;max-width:620px;padding:8px}.handwriting .notice p{font-size:18px;line-height:1.3;margin:0}.handwriting .choices{gap:6px}.handwriting .choices button{font-size:26px;padding:6px 12px}@media(max-width:650px){.shell-exercise{padding:8px 10px 12px}.exercise-card{padding:10px;gap:8px}.exercise-card .frame{gap:4px;padding:6px}.exercise-card .tray{grid-template-columns:52px minmax(0,1fr) auto;padding:6px}}@media(min-width:900px)and (max-height:850px){.exercise-discovery{grid-template-columns:minmax(0,1.3fr) minmax(0,1fr);align-items:center}.exercise-discovery .exercise-heading{grid-column:1 / -1}.exercise-discovery .frame{grid-column:1;grid-row:2 / 5}.exercise-discovery .coach{grid-column:2;grid-row:2}.exercise-discovery .tray{grid-column:2;grid-row:3}.exercise-discovery .exercise-actions{grid-column:2;grid-row:4}.exercise-discovery .feedback,.exercise-discovery .error{grid-column:1 / -1}.handwriting[data-mode=handwritten]{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);gap:8px 16px;align-items:center}.handwriting[data-mode=handwritten]>*{grid-column:2}.handwriting[data-mode=handwritten] .writing-pad{grid-column:1;grid-row:1 / 6;width:100%;height:200px;margin:0}.handwriting[data-mode=handwritten] .notice{margin:0}.handwriting[data-mode=handwritten] .notice .controls{margin-top:8px}}@media(prefers-reduced-motion:no-preference){button,.counter{transition:background .15s,box-shadow .15s}.feedback{animation:appear .2s ease-out}@keyframes appear{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}}.base-ten{display:grid;gap:8px;justify-items:center}.exercise-discovery .base-ten .frame{grid-column:auto;grid-row:auto}.decade-overview{display:flex;flex-wrap:wrap;justify-content:center;gap:8px}.mini-decade{display:flex;gap:6px;align-items:center;background:#e7f3ff;border:2px solid #8eafc9;border-radius:10px;padding:6px}.mini-decade>span{font-weight:800;font-size:16px}.mini-decade.current{border-color:#24324a;background:#fff4cb}.base-ten>small{font-size:14px;line-height:1.2}.mini-decade>div{display:grid;grid-template-columns:repeat(5,9px);gap:3px}.mini-dot{width:9px;height:9px;border:1px solid #667c98;border-radius:50%;background:#fff}.mini-dot.given{background:#ef7676}.mini-dot.added{background:#6fb8ec}.digit-pads{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;max-width:540px;margin:0 auto}.digit-pads label{font-size:15px}.exercise-card .digit-pads .writing-pad{width:100%;height:clamp(135px,22vh,190px);margin:4px 0}.number-writing{text-align:center}.number-writing h2{font-size:22px;margin:4px}.number-writing .notice{margin:8px auto;padding:8px;max-width:540px}.number-writing .notice p{margin:0}.number-writing .controls{margin-top:8px}.number-output{display:block;font-size:32px;font-weight:800}.number-keypad{display:grid;grid-template-columns:repeat(6,minmax(48px,1fr));gap:6px;max-width:540px;margin:4px auto}.number-keypad button{min-width:0;padding:8px;font-size:22px}.number-keypad button:last-child{grid-column:span 2;font-size:15px}.block-tile{margin:4px}@media(min-width:900px)and (max-height:850px){.exercise-discovery .base-ten{grid-column:1;grid-row:2 / 5}.exercise-discovery.is-feedback .feedback{grid-column:2;grid-row:2 / 5;align-self:center}}@media(max-width:450px){.number-keypad{grid-template-columns:repeat(4,minmax(48px,1fr))}.mini-decade{gap:4px;padding:4px}.mini-decade>div{grid-template-columns:repeat(5,7px);gap:2px}.mini-dot{width:7px;height:7px}}