:root{--ink:#183d38;--muted:#647970;--green:#12665b;--green-dark:#0c4c43;--mint:#e3eee5;--lime:#e5edb9;--cream:#f8f8f2;--border:#dce4db;--orange:#f2b467;--white:#fff;--violet:#eee8f8;--shadow:0 8px 28px #173c3710;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--cream);font-synthesis:none}*{box-sizing:border-box}body{margin:0}button,input,select{font:inherit}button,a,input{ -webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default;opacity:.6}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #cb812a;outline-offset:4px}button{color:inherit}h1,h2,h3,p{margin:0}h1{font-size:clamp(30px,5vw,46px);line-height:1.13;letter-spacing:-1.4px;font-weight:750}h2{font-size:23px;letter-spacing:-.6px;line-height:1.3}h3{font-size:17px}p{line-height:1.65}.eyebrow{text-transform:uppercase;letter-spacing:1.7px;font-size:11px;font-weight:750;color:var(--green);margin-bottom:10px}.muted{color:var(--muted)}.small{font-size:13px}.topbar{height:84px;max-width:1150px;padding:0 32px;margin:auto;display:flex;align-items:center;gap:22px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-size:21px;font-weight:800;letter-spacing:-.7px}.brand-light{font-weight:450}.header-note{font-size:13px;color:var(--muted);margin-left:auto}.gem{border:1px solid #e2d9bc;background:#fff9e6;border-radius:30px;min-height:40px;padding:8px 15px;font-weight:750;color:#775519;display:flex;gap:8px;align-items:center}.shell{max-width:1086px;margin:auto;padding:25px 0 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.16s}.btn:hover{background:var(--green-dark)}.btn:active{transform:translateY(1px)}.btn.lime{background:var(--lime);color:var(--ink)}.btn.secondary{background:white;color:var(--ink);border-color:var(--border)}.btn.ghost{background:transparent;color:var(--ink);border-color:var(--border)}.btn.wide{width:100%}.side{display:flex;flex-direction:column;gap:18px}.today-card{background:#eff1e5}.row{display:flex;align-items:center;justify-content:space-between;gap:12px}.gap{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.step-list{display:flex;flex-direction:column;gap:17px;margin-top:22px}.step{display:flex;align-items:center;gap:12px}.stepnum{width:33px;height:33px;display:grid;place-items:center;background:white;border-radius:11px;font-size:13px;font-weight:700;flex-shrink:0}.step strong{font-size:14px}.step p{font-size:12px;color:var(--muted)}.snack-card{background:#f8eddc;box-shadow:none}.snack-art{font-size:32px;letter-spacing:-1px;font-weight:750;color:#9b641e;padding:13px 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p{font-size:12px;color:var(--muted)}.topic-status{font-size:11px;color:var(--green);margin-top:13px;display:flex;gap:4px;align-items:center}.dot{height:5px;width:5px;background:#dce5dd;border-radius:50%}.dot.on{background:var(--green)}.bottom-nav{position:fixed;bottom:0;left:0;right:0;display:flex;justify-content:center;gap:60px;background:#fffffff5;border-top:1px solid var(--border);padding:10px 16px max(12px,env(safe-area-inset-bottom));z-index:10;backdrop-filter:blur(12px)}.bottom-nav button{border:0;background:none;color:var(--muted);font-size:11px;min-width:80px;padding:3px 8px;display:flex;flex-direction:column;align-items:center;gap:3px}.bottom-nav button span{font-size:22px;line-height:24px}.bottom-nav button.active{color:var(--green);font-weight:750}#toast{position:fixed;bottom:92px;left:50%;transform:translateX(-50%);background:var(--ink);color:white;border-radius:12px;padding:12px 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22px;min-height:140px}.bar-label{font-size:12px;margin-bottom:8px;color:var(--muted)}.fractionbar{height:55px;background:#dfe6da;position:relative;margin-bottom:18px;border-radius:5px;overflow:hidden}.fraction-fill{background:#438f7b;height:100%}.fraction-cut{position:absolute;top:0;bottom:0;width:2px;background:#f3f6ee}.fraction-numberline{margin:28px 6px 30px;border-top:2px solid #81988c;position:relative;height:24px}.fraction-point{position:absolute;top:-6px;width:10px;height:10px;background:var(--green);border-radius:50%;transform:translateX(-50%)}.fraction-label{position:absolute;top:9px;font-size:12px}.visual input[type=range]{width:100%;accent-color:var(--green);min-height:32px}.formula{text-align:center;font-size:28px;display:flex;align-items:center;justify-content:center;gap:18px;margin:14px 0;font-weight:600}.frac{display:inline-flex;flex-direction:column;align-items:stretch;text-align:center;vertical-align:middle;line-height:1.3;min-width:30px}.frac 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.grid-square{gap:1px;margin:0}.layers small{display:block;text-align:center;font-size:10px;margin-top:4px}.clock-face{width:150px;height:150px;border-radius:50%;border:2px solid #a4b9a7;margin:10px auto;position:relative;display:grid;place-items:center;background:conic-gradient(#95bea4 0deg 90deg,#e1eadc 90deg)}.clock-face strong{background:#f3f6ee;border-radius:50%;width:76px;height:76px;display:grid;place-items:center;font-size:17px}.progress-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:22px 0}.stat .value{font-size:32px;font-weight:750;margin:5px 0}.stat p{font-size:13px;color:var(--muted)}.skill-row{padding:18px 0;border-bottom:1px solid var(--border)}.skill-row:last-child{border-bottom:0}.skill-row p{font-size:13px;color:var(--muted);margin-top:5px}.level-track{display:flex;gap:5px;margin-top:12px}.level-track span{height:7px;background:var(--mint);flex:1;border-radius:4px}.level-track span.on{background:var(--green)}.badge-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:18px}.badge{background:#f1f3e8;border-radius:17px;padding:20px 12px;text-align:center}.badge span{display:block;font-size:28px;margin-bottom:8px}.badge.locked{opacity:.55}.badge p{font-size:11px;color:var(--muted);margin-top:5px}.guide{max-width:780px}.guide .card{margin:20px 0}.guide p{margin:12px 0}.guide li{margin:8px 0;line-height:1.65}.guide ul{padding-left:23px}.guide summary{cursor:pointer;font-weight:650;min-height:35px}.guide details+details{border-top:1px solid var(--border);padding-top:16px;margin-top:16px}.success-art{font-size:58px;text-align:center;margin:14px 0}.summary{text-align:center}.summary h1{font-size:32px;margin:16px 0}.summary p{max-width:420px;margin:10px auto;color:var(--muted)}.summary .progress-grid{grid-template-columns:repeat(2,1fr)}.summary .btn{margin-top:15px}.session-skills{text-align:left;margin:22px 0}.session-skills div{padding:9px 0;border-bottom:1px solid var(--border);font-size:13px}.notice{padding:12px 15px;border-radius:12px;background:#fff0d8;margin:12px 0;font-size:13px;line-height:1.5}.install-note{margin-top:22px;font-size:12px;color:var(--muted);text-align:center}.footer-small{font-size:11px;color:var(--muted);margin-top:22px}.view-enter{animation:enter .25s ease-out}@keyframes enter{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:translateY(0)}}@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}@media(max-width:1150px){.shell{padding-left:28px;padding-right:28px}}@media(max-width:740px){.topbar{height:72px;padding:0 20px}.header-note{display:none}.gem{margin-left:auto}.shell{padding:18px 20px 110px}.intro{margin-bottom:22px}.intro .pill{display:none}.intro p{font-size:14px}.layout{grid-template-columns:1fr;gap:16px}.hero{min-height:365px;padding:24px}.hero h2{font-size:27px;max-width:280px}.hero-art{height:164px}.side{display:grid;grid-template-columns:1fr 1fr;gap:12px}.side .card{padding:18px;border-radius:20px}.side h3{font-size:15px}.step-list{gap:12px;margin-top:16px}.stepnum{display:none}.step p{font-size:11px}.snack-art{font-size:26px}.side .btn{padding:10px 12px;min-height:43px;font-size:12px}.topics{grid-template-columns:1fr 1fr;gap:12px}.topic{padding:15px;min-height:151px;flex-direction:column;gap:11px}.topic-icon{width:36px;height:36px;border-radius:11px;font-size:19px}.topic-status{margin-top:9px}.section-head{margin-top:25px}.section-head h2{font-size:21px}.section-head p{font-size:11px}.bottom-nav{gap:22px}.progress-grid{gap:10px}.progress-grid .card{padding:16px}.stat .value{font-size:27px}.stat p{font-size:11px}.play-shell{padding:10px 15px 100px}.exercise{padding:22px 18px;border-radius:20px}.exercise h1{font-size:25px}.question{font-size:16px}.visual{padding:17px}.answer-form .btn{padding:13px 15px}.badge-grid{gap:8px}.badge{padding:15px 8px}.badge strong{font-size:12px}.guide .card{padding:21px}.hero-bottom .small{font-size:11px}.hero-bottom .btn{padding:13px 16px}.formula{font-size:26px}.section-head{align-items:flex-end}}@media(max-width:350px){.shell{padding-left:15px;padding-right:15px}.topbar{padding:0 15px}.brand{font-size:19px}.hero-bottom{align-items:flex-start;flex-direction:column}.side{grid-template-columns:1fr}.hero-art{height:150px}.answer-form{flex-wrap:wrap}.answer-form .btn{width:100%}.bottom-nav{gap:8px}.visual{padding:13px}}

body.playing .bottom-nav{display:none}body.playing .play-shell{padding-bottom:40px}body.playing .topbar{height:65px}@media(max-width:740px){.playing .visual{margin:15px 0;padding:15px}.playing .fractionbar{height:38px;margin-bottom:13px}.playing .fraction-numberline{margin-top:20px;margin-bottom:15px}.playing .exercise h1{font-size:24px}.playing .bar-label{margin-bottom:6px}.playing .question{margin-bottom:13px}}
/* Clear, persistent answer feedback. */
.answer-feedback{border:2px solid #6b9e88;border-radius:18px;background:#edf7ed;padding:20px;margin-top:20px;scroll-margin:16px;text-align:left;overflow-wrap:anywhere}.answer-feedback.retry,.answer-feedback.solution{background:#fff5e3;border-color:#c48a3a}.feedback-heading{display:flex;align-items:flex-start;gap:13px}.feedback-heading h2{font-size:25px;line-height:1.2;margin:0 0 6px;letter-spacing:-.4px}.feedback-heading p{font-size:15px;line-height:1.5}.feedback-symbol{display:grid;place-items:center;border-radius:50%;width:42px;height:42px;flex-shrink:0;background:#176c4f;color:#fff;font-size:27px;font-weight:750}.retry .feedback-symbol,.solution .feedback-symbol{background:#9c6519}.feedback-explanation{margin-top:16px;font-size:15px;line-height:1.65}.feedback-points{margin-top:12px;font-size:12px;color:#536b5b}.answer-feedback .btn{margin-top:17px}.answer-form input.answer-correct{border:2px solid #267849;background:#edf7ed;color:#164d32}.answer-form input.answer-incorrect{border:2px solid #b77b25;background:#fff8eb}.answer-form input[readonly]{opacity:1}.answer-state{align-self:center;color:#85551d;font-size:13px;font-weight:700;white-space:nowrap}.answer-state.correct{color:#19643b}.choice-note{display:block;margin-top:6px;font-size:11px}.choice:disabled{opacity:1}.choice:disabled:not(.correct):not(.wrong):not(.selected){opacity:.65}.answer-validation{margin-top:10px;color:#954520;font-size:14px;line-height:1.5}.answer-feedback:focus{outline:none}.answer-feedback:focus-visible{outline:3px solid #8b682d;outline-offset:3px}@media(max-width:400px){.answer-feedback{padding:16px}.feedback-heading h2{font-size:23px}.feedback-symbol{width:36px;height:36px;font-size:23px}.feedback-heading{gap:10px}.answer-form:has(input[readonly]){flex-wrap:wrap}.answer-form:has(input[readonly]) label{flex-basis:65%}.answer-state{white-space:normal}}
/* Local learner profiles and daily learning streaks. */
[hidden]{display:none!important}.profile-switch{margin-left:auto;max-width:210px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;border:1px solid var(--border);background:white;border-radius:24px;padding:9px 13px;min-height:44px;font-size:14px;font-weight:650}.header-note{display:none}.topbar{gap:12px}.gem{margin-left:0}.profiles-shell{max-width:850px}.profile-welcome{text-align:center;margin:24px auto 30px}.profile-welcome p{margin-top:14px;color:var(--muted)}.profile-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.profile-tile{min-width:0;border:1.5px solid var(--border);border-radius:24px;padding:24px 12px;background:white;display:flex;flex-direction:column;align-items:center;gap:10px;box-shadow:var(--shadow)}.profile-tile strong{font-size:20px;overflow-wrap:anywhere;max-width:100%}.profile-tile:hover{border-color:var(--green);background:#f0f6e9}.profile-avatar{font-size:52px;line-height:1.4}.profile-add{border-style:dashed;background:#eff4e7}.profile-fire{color:#905219;background:#fff1db;padding:6px 12px;border-radius:20px;font-size:13px}.choosing-profile .bottom-nav{display:none}.profile-form-card{max-width:520px;margin:10px auto}.profile-form-card h1{font-size:32px}.profile-form-card p{margin:14px 0;color:var(--muted);font-size:14px}.profile-name-label{display:block;font-weight:650;margin:24px 0 8px}.profile-name{border:1.5px solid #a6bdb1;border-radius:12px;padding:13px;width:100%;font-size:20px;min-height:50px}.avatar-field{padding:0;border:0;margin:24px 0}.avatar-field legend{font-weight:650;margin-bottom:12px}.avatar-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:9px}.avatar-option{position:relative;display:flex;flex-direction:column;align-items:center;border:2px solid var(--border);border-radius:15px;padding:10px 4px;cursor:pointer}.avatar-option input{position:absolute;opacity:0;width:1px;height:1px}.avatar-option:has(input:checked){border-color:var(--green);background:var(--mint)}.avatar-option:has(input:focus-visible){outline:3px solid #cb812a;outline-offset:3px}.avatar-option span{font-size:30px}.avatar-option small{font-size:10px;margin-top:4px}.profile-form-card .btn+.btn{margin-top:10px}.profile-reset{margin-top:28px;border-top:1px solid var(--border);padding-top:20px;font-size:13px}.profile-reset summary{cursor:pointer;min-height:40px}.streak-card{border:1px solid #edcf9f;background:#fff6e7;border-radius:22px;padding:22px 25px;margin-bottom:24px}.streak-main{display:flex;align-items:center;gap:16px}.flame{font-size:45px;filter:grayscale(.75);opacity:.8}.flame.lit{filter:none;opacity:1;animation:flame-light .6s ease-out}.streak-main h2{font-size:22px}.streak-main p{font-size:13px;color:#805c35;margin-top:4px}.streak-best{font-size:12px;white-space:nowrap;margin-left:auto;color:#805c35}.streak-week{display:flex;gap:10px;margin-top:18px;max-width:420px}.streak-day{flex:1;text-align:center;min-width:0}.streak-day span{display:block;font-size:11px;color:#805c35;margin-bottom:7px}.streak-day strong{display:grid;place-items:center;border:1px solid #e7d7be;background:white;border-radius:50%;width:34px;height:34px;margin:auto;color:#c4b495}.streak-day.done strong{background:#df741a;color:white;border-color:#df741a}.streak-day.today strong{outline:2px solid #a85516;outline-offset:3px}.streak-note{font-size:11px;color:#805c35;margin-top:18px;max-width:650px}.round-flame{background:#fff1d9;color:#874b10;border-radius:16px;padding:15px;font-size:18px;font-weight:700;margin:16px auto;max-width:400px}@keyframes flame-light{from{transform:scale(.8)}60%{transform:scale(1.15)}to{transform:scale(1)}}@media(max-width:740px){.topbar{flex-wrap:wrap;height:auto;min-height:76px;padding-top:12px;padding-bottom:12px}.playing .topbar{height:auto;min-height:65px}.brand{font-size:18px;gap:6px}.brand img{width:30px;height:30px}.profile-switch{max-width:135px;font-size:12px;padding:8px 10px}.gem{font-size:12px;padding:7px 10px;min-height:36px}.profile-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.profile-welcome{margin-top:16px}.profile-welcome h1{font-size:32px}.profile-tile strong{font-size:18px}.profile-tile .small{font-size:11px}.streak-card{padding:18px}.streak-main{gap:10px;flex-wrap:wrap}.streak-main>div{flex:1}.streak-main h2{font-size:20px}.streak-best{margin-left:0;width:100%}.streak-main p{font-size:12px}.streak-week{gap:5px}.streak-day strong{width:30px;height:30px}.flame{font-size:38px}.profile-form-card{padding:20px}.avatar-grid{gap:7px}}@media(max-width:400px){.topbar .brand{flex:1 1 calc(100% - 150px)}.topbar .gem{margin-left:auto}.topbar:has(.gem:not([hidden])){column-gap:8px}.profile-switch{max-width:120px}.streak-day strong{width:27px;height:27px}}
.choosing-profile #shell-gems{display:none}