:root{--brand: #6d28d9;--brand-ink: #ffffff;--bg: #ffffff;--surface: #f7f7f8;--ink: #16171a;--muted: #64666e;--line: #e3e4e8;--danger: #b42318;--warn: #8a5300;--warn-bg: #fff6e5;--space: 8px;--radius: 10px;--font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;color-scheme:light dark}@media(prefers-color-scheme:dark){:root{--bg: #0e0f12;--surface: #16181d;--ink: #f2f3f5;--muted: #9a9daa;--line: #262a32;--danger: #ff9a90;--warn: #ffc76b;--warn-bg: #2a2113}}*{box-sizing:border-box}body{margin:0;font-family:var(--font);font-size:16px;line-height:1.5;color:var(--ink);background:var(--bg);padding:env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left)}main{max-width:720px;margin:0 auto;padding:calc(var(--space) * 2)}.boot{padding:calc(var(--space) * 6);text-align:center;color:var(--muted)}.env{padding:calc(var(--space) * 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button{display:flex;flex-direction:column;align-items:flex-start;padding:calc(var(--space) * 1.5);height:auto}.stats b{font-size:1.6rem}.stats span{color:var(--muted);font-size:.8rem;font-weight:400}.list{list-style:none;margin:0 0 calc(var(--space) * 2);padding:0}.list li{display:flex;align-items:center;justify-content:space-between;gap:var(--space);padding:calc(var(--space) * 1.5) 0;border-bottom:1px solid var(--line);flex-wrap:wrap}.list li.read{opacity:.55}.row{display:flex;gap:calc(var(--space) * .5);align-items:center}.muted{color:var(--muted)}.small{font-size:.85rem}.error{color:var(--danger);font-weight:600}.warn{background:var(--warn-bg);color:var(--warn);padding:calc(var(--space) * 1.5);border-radius:var(--radius);font-weight:600}footer{max-width:720px;margin:0 auto;padding:calc(var(--space) * 2)}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}.update-bar{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;padding:calc(var(--space) * 1.25) calc(var(--space) * 2);background:var(--brand);color:var(--brand-ink);font-weight:600}.update-bar button{min-height:36px;background:#0000001f;border-color:#0003;color:var(--brand-ink)}.update-bar button.primary{background:var(--brand-ink);color:var(--brand);border-color:var(--brand-ink);width:auto}.debug-tab{position:fixed;right:12px;bottom:calc(12px + env(safe-area-inset-bottom));z-index:60;min-height:34px;padding:0 10px;font-size:.74rem;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;background:var(--surface);border:1px solid var(--line);opacity:.8}.debug-tab:hover{opacity:1}.debug-panel{position:fixed;inset:auto 0 0;z-index:60;max-height:62vh;display:flex;flex-direction:column;background:var(--surface);border-top:2px solid var(--brand);padding:12px 14px calc(12px + env(safe-area-inset-bottom))}.debug-panel>header{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:8px}.debug-panel button{min-height:32px;padding:0 10px;font-size:.78rem}.debug-lines{list-style:none;margin:0 0 8px;padding:0;overflow:auto;flex:1;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.72rem;line-height:1.55}.debug-lines li{display:flex;gap:8px;padding:1px 0;border-bottom:1px solid var(--line)}.debug-lines .ts{color:var(--muted);flex:0 0 auto}.debug-lines .lvl{flex:0 0 34px;text-transform:uppercase;font-size:.62rem;padding-top:2px}.debug-lines .msg{word-break:break-word}.lvl-error .lvl,.lvl-error .msg{color:var(--danger)}.lvl-warn .lvl{color:var(--warn)}.lvl-net .lvl{color:var(--muted)}.lvl-app .lvl{color:var(--brand)}.install-prompt{display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;max-width:720px;margin:28px auto 0;padding:14px 16px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}.install-prompt p{margin:2px 0 0}.install-prompt button{min-height:38px}.reveal{border:2px solid var(--brand);border-radius:var(--radius);padding:calc(var(--space) * 2);margin-bottom:calc(var(--space) * 2);display:grid;gap:calc(var(--space) * 1.5)}.reveal code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.82rem;word-break:break-all;background:var(--bg);padding:calc(var(--space) * 1.5);border-radius:var(--radius);-webkit-user-select:all;user-select:all}:root{--good: #16a34a;--good-bg: #dcfce7;--almost: #d97706;--almost-bg: #fef3c7;--idk: #0284c7;--idk-bg: #e0f2fe;--hot: #f97316;--c0: #e11d48;--c1: #2563eb;--c2: #16a34a;--c3: #d97706;--c4: #7c3aed;--c5: #0891b2}@media(prefers-color-scheme:dark){:root{--good-bg: #0f2e1a;--almost-bg: #2e2208;--idk-bg: #0b2536;--brand: #8b5cf6}}main.wide{max-width:1180px}.bar .brand{border:none;background:none;font-size:1.1rem;font-weight:800;display:flex;gap:6px;align-items:center;color:var(--brand);padding:0 4px}.bar nav button{min-width:44px;display:inline-flex;align-items:center;justify-content:center}.lang{display:inline-flex;gap:2px}.lang button{padding:0 6px;opacity:.45}.lang button.on{opacity:1;border-color:var(--brand)}.icon{vertical-align:-.2em;flex:0 0 auto}button.big{min-height:56px;font-size:1.1rem;display:flex;align-items:center;justify-content:center;gap:8px}button.narrow{width:auto;display:inline-flex;align-items:center;gap:6px;white-space:nowrap}button.danger{color:var(--danger)}button.link.back{display:inline-flex;align-items:center;gap:4px;margin-bottom:12px;text-decoration:none}.welcome{max-width:480px;margin:0 auto}.welcome-lang{display:flex;justify-content:flex-end}.hero{text-align:center;padding:16px 0 8px}.hero h1{margin:8px 0 4px;font-size:1.9rem;line-height:1.15}.hero-mark{width:84px;height:84px;margin:0 auto;border-radius:50%;display:grid;place-items:center;color:#fff;background:linear-gradient(135deg,var(--c4),var(--c0) 60%,var(--c3));box-shadow:0 10px 30px #6d28d959;animation:bob 3s ease-in-out infinite}.tagline{font-weight:800;font-size:1.15rem;color:var(--brand);margin:0}.join-note{background:var(--idk-bg);color:var(--idk);padding:10px 12px;border-radius:var(--radius);font-weight:600}@keyframes bob{0%,to{transform:translateY(0) rotate(-4deg)}50%{transform:translateY(-6px) rotate(4deg)}}.live-banner{display:flex;align-items:center;gap:14px;width:100%;min-height:72px;margin-bottom:16px;text-align:left;background:linear-gradient(90deg,var(--c0),var(--c3));color:#fff;border:none;border-radius:16px;padding:12px 18px;font-size:1.05rem;box-shadow:0 8px 24px #e11d4859;animation:glow 1.6s ease-in-out infinite}.live-banner .live-go{margin-left:auto;display:flex;align-items:center;gap:4px;font-weight:800}.live-banner>.icon:last-child{margin-left:auto}.pulse{width:14px;height:14px;border-radius:50%;background:#fff;flex:0 0 auto;animation:ping 1.2s ease-out infinite}@keyframes ping{0%{box-shadow:0 0 #fffc}to{box-shadow:0 0 0 14px #fff0}}@keyframes glow{0%,to{filter:brightness(1)}50%{filter:brightness(1.12)}}.me-card{display:flex;gap:18px;align-items:center}.me-card>div:last-child{flex:1;min-width:0}.level-title{margin:0;font-size:1.7rem;line-height:1.1}.xp-line{margin:4px 0 8px}.xp-bar,.progress,.mini-bar{height:10px;background:var(--line);border-radius:99px;overflow:hidden}.xp-bar>div,.progress>div,.mini-bar>span{display:block;height:100%;background:linear-gradient(90deg,var(--c4),var(--c0));border-radius:99px;transition:width .6s cubic-bezier(.2,.9,.3,1.3)}.progress{height:6px;margin:6px 0 14px}.mini-bar{height:5px;margin-top:4px;width:100%}.ring{position:relative;flex:0 0 auto}.ring svg{transform:rotate(-90deg)}.ring-track{fill:none;stroke:var(--line);stroke-width:9}.ring-fill{fill:none;stroke:var(--brand);stroke-width:9;stroke-linecap:round;transition:stroke-dashoffset .8s}.ring-in{position:absolute;inset:0;display:grid;place-items:center;align-content:center;color:var(--brand)}.ring-in b{font-size:1.3rem;line-height:1}.join-row input{margin:0;text-transform:uppercase;letter-spacing:.2em;font-weight:700}.join-row button{width:auto;flex:0 0 auto}.module-title{margin:16px 0 6px}.lesson-list{list-style:none;margin:0;padding:0}.lesson-list li{border-bottom:1px solid var(--line)}.lesson-list button,.lesson-teach{display:flex;align-items:center;gap:12px;width:100%;text-align:left;border:none;background:none;padding:10px 0;min-height:60px}.lesson-num{flex:0 0 auto;min-width:44px;height:44px;border-radius:12px;display:grid;place-items:center;font-weight:800;background:var(--brand);color:var(--brand-ink)}.lesson-num.big{width:64px;height:64px;font-size:1.4rem}.lesson-name{flex:1;display:flex;flex-direction:column;font-weight:600;min-width:0}.badges{display:grid;grid-template-columns:repeat(auto-fill,minmax(96px,1fr));gap:10px}.badge{display:flex;flex-direction:column;align-items:center;gap:4px;text-align:center;padding:12px 6px;border-radius:14px;border:1px dashed var(--line);color:var(--muted);font-size:.8rem;font-weight:600}.badge.earned{border:1px solid transparent;color:#fff;background:linear-gradient(135deg,var(--c3),var(--c0));box-shadow:0 6px 16px #d977064d}.checklist{list-style:none;padding:0;margin:0}.checklist label{display:flex;align-items:center;gap:12px;padding:10px 0;border-bottom:1px solid var(--line);font-weight:500;margin:0;min-height:52px}.checklist input{width:26px;height:26px;margin:0;accent-color:var(--good);flex:0 0 auto}.checklist label.done span:first-of-type{text-decoration:line-through;color:var(--muted)}.fb-xp{color:var(--good);font-weight:800;margin-left:auto}.step h2{font-size:1.45rem;line-height:1.25;margin:0 0 10px}.step p{margin:0 0 10px;font-size:1.05rem}.step-kind{display:inline-block;font-size:.75rem;font-weight:800;text-transform:uppercase;letter-spacing:.08em;color:var(--brand);margin-bottom:6px}.step-big h2{font-size:clamp(2rem,4.5vw,4rem)}.step-big p{font-size:clamp(1.3rem,2.4vw,2.2rem)}.teacher-note{background:var(--warn-bg);color:var(--warn);border-radius:var(--radius);padding:10px 12px;margin-top:10px;font-size:.9rem}.teacher-note p{font-size:.9rem;margin:4px 0 0}.answer{display:grid;gap:10px;margin-top:16px}.pad{display:grid;gap:10px}.pad-2{grid-template-columns:1fr 1fr}.choice{min-height:64px;border:none;border-radius:16px;color:#fff;font-size:1.1rem;font-weight:700;text-align:left;display:flex;align-items:center;gap:12px;padding:12px 16px;box-shadow:0 4px #0003;transition:transform .08s}.pad-2 .choice{justify-content:center;font-size:1.4rem;min-height:90px}.choice:active:not(:disabled){transform:translateY(3px) scale(.98);box-shadow:0 1px #0003}.choice:disabled{opacity:.6}.c0{background:var(--c0)}.c1{background:var(--c1)}.c2{background:var(--c2)}.c3{background:var(--c3)}.c4{background:var(--c4)}.c5{background:var(--c5)}.choice.idk{background:var(--idk-bg);color:var(--idk);box-shadow:none;border:2px dashed var(--idk);justify-content:center}.choice-letter{width:32px;height:32px;border-radius:8px;background:#ffffff40;display:grid;place-items:center;flex:0 0 auto}.guess{display:grid;gap:10px}.guess label{margin:0}.guess-row{display:flex;align-items:center;gap:8px}.guess-row input{font-size:1.8rem;font-weight:800;text-align:center;margin:0}.guess-unit{font-size:1.6rem;font-weight:800;color:var(--muted)}.guess .choice{justify-content:center}.feedback{margin-top:16px;border-radius:16px;padding:16px;animation:pop .35s cubic-bezier(.2,.9,.3,1.4)}.fb-right{background:var(--good-bg);color:var(--good)}.fb-close,.fb-wrong{background:var(--almost-bg);color:var(--almost)}.fb-idk{background:var(--idk-bg);color:var(--idk)}.fb-poll{background:var(--surface);color:var(--brand);border:1px solid var(--line)}.fb-head{display:flex;align-items:center;gap:10px}.fb-cheer{font-size:1.5rem;font-weight:800}.fb-head .fb-xp{font-size:1.2rem}.fb-streak{color:var(--hot);font-weight:800;margin-top:4px}.fb-answer{margin:10px 0 0;color:var(--ink)}.fb-explain{color:var(--ink);margin-top:8px}.fb-explain p{margin:0 0 6px}@keyframes pop{0%{transform:scale(.8);opacity:0}to{transform:scale(1);opacity:1}}.live-student,.study{max-width:560px;margin:0 auto}.live-top{display:flex;justify-content:space-between;align-items:center;gap:8px}.live-chips{display:flex;gap:6px}.chip{display:inline-flex;align-items:center;gap:4px;padding:4px 10px;border-radius:99px;background:var(--surface);border:1px solid var(--line);font-weight:700;font-size:.9rem}.chip.hot{background:var(--hot);color:#fff;border-color:var(--hot);animation:pop .3s}.waiting{text-align:center;color:var(--muted);padding:24px 0;font-weight:600}.callon-overlay{position:fixed;inset:0;z-index:80;display:grid;place-items:center;padding:24px;background:radial-gradient(circle,var(--c3),var(--c0));color:#fff;animation:pop .3s}.callon-card{text-align:center;animation:wiggle 1s ease-in-out infinite}.callon-card h1{font-size:clamp(3rem,12vw,7rem);margin:8px 0;line-height:1}.callon-card p{font-size:1.2rem;max-width:22ch;margin:0 auto}@keyframes wiggle{0%,to{transform:rotate(-2deg)}50%{transform:rotate(2deg) scale(1.03)}}.modal{position:fixed;inset:0;z-index:70;background:#00000080;display:grid;place-items:center;padding:16px}.modal-card{background:var(--bg);border-radius:18px;padding:20px;max-width:560px;width:100%;max-height:88vh;overflow:auto}.review-item{border-top:1px solid var(--line);padding:12px 0}.done-screen{text-align:center;display:flex;flex-direction:column;align-items:center;gap:10px;padding-top:24px;color:var(--ink)}.done-screen>.icon{color:var(--c3)}.big-xp{font-size:1.4rem;margin:0}.board{list-style:none;padding:0;margin:8px 0;width:100%;max-width:480px}.board li{display:flex;align-items:center;gap:12px;padding:10px 14px;border-radius:12px;margin-bottom:6px;background:var(--surface);font-weight:700}.board li:first-child{background:linear-gradient(90deg,var(--c3),#facc15);color:#1a1a1a}.board li.me{outline:3px solid var(--brand)}.board-rank{width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:#0000001a}.board-name{flex:1;text-align:left}.class-row{display:flex;align-items:center;gap:10px;width:100%;border:none;background:none;text-align:left}.class-row .icon{margin-left:auto}.class-head{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap}.code-big{font-size:2.6rem;font-weight:900;letter-spacing:.18em;margin:0;color:var(--brand)}.reteach-card{border-color:var(--idk);background:var(--idk-bg)}.table{width:100%;border-collapse:collapse;font-size:.92rem}.table th,.table td{text-align:left;padding:8px 6px;border-bottom:1px solid var(--line)}.console-top{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:10px}.console-top .row button{display:inline-flex;gap:6px;align-items:center}.scrubber{display:flex;gap:4px;flex-wrap:wrap;margin-bottom:12px}.dot{min-height:22px;width:22px;padding:0;border-radius:6px;background:var(--line);border:none}.dot-question{background:color-mix(in srgb,var(--c4) 45%,var(--line))}.dot-poll{background:color-mix(in srgb,var(--c5) 45%,var(--line))}.dot.on{background:var(--brand);outline:3px solid color-mix(in srgb,var(--brand) 40%,transparent)}.console-grid{display:grid;grid-template-columns:1.1fr 1fr;gap:16px}@media(max-width:860px){.console-grid{grid-template-columns:1fr}}.nav-row{flex-wrap:wrap;margin-top:12px;justify-content:space-between}.nav-row button{display:inline-flex;align-items:center;gap:6px}.called{display:flex;align-items:center;gap:12px;padding:12px;border-radius:14px;background:linear-gradient(90deg,var(--c3),var(--c0));color:#fff;margin-bottom:12px}.called button{margin-left:auto}.called-name{font-size:1.5rem}.bars{display:grid;gap:6px;margin-bottom:12px}.bar-row{display:grid;grid-template-columns:minmax(80px,38%) 1fr 32px;gap:8px;align-items:center;font-size:.9rem}.bar-label{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.bar-track{height:16px;background:var(--line);border-radius:99px;overflow:hidden}.bar-track span{display:block;height:100%;background:var(--c1);border-radius:99px;transition:width .4s}.bar-row.good .bar-track span{background:var(--good)}.bar-row.good .bar-label{font-weight:800;color:var(--good)}.bar-n{font-weight:800;text-align:right}.callon-row{display:flex;gap:6px;flex-wrap:wrap;align-items:center;margin-bottom:12px}.pool{min-height:38px;font-size:.88rem}.pool-right{border-color:var(--good);color:var(--good)}.pool-wrong{border-color:var(--almost);color:var(--almost)}.pool-idk{border-color:var(--idk);color:var(--idk)}.groups{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.group{border-radius:12px;padding:8px 10px;background:var(--bg);border:1px solid var(--line)}.group h4{margin:0 0 6px;display:flex;justify-content:space-between;font-size:.85rem}.group-right h4{color:var(--good)}.group-wrong h4{color:var(--almost)}.group-idk h4{color:var(--idk)}.names{display:flex;flex-wrap:wrap;gap:4px}.name{min-height:32px;padding:0 10px;font-size:.85rem;border-radius:99px}.present{min-height:100vh;display:flex;flex-direction:column;padding:24px 40px;background:var(--bg)}.present-top{display:flex;justify-content:space-between;font-size:1.3rem;color:var(--muted);font-weight:700}.present-main{flex:1;display:flex;flex-direction:column;justify-content:center;max-width:1400px;margin:0 auto;width:100%}.present-choices{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:24px}.pchoice{color:#fff;border-radius:20px;padding:20px 24px;font-size:clamp(1.3rem,2.4vw,2.2rem);font-weight:800;display:flex;align-items:center;gap:14px;transition:opacity .3s,transform .3s}.pchoice b{margin-left:auto;font-size:1.2em}.pchoice.good{outline:6px solid var(--ink);transform:scale(1.03)}.present-answer{grid-column:1 / -1;font-size:clamp(1.6rem,3vw,2.8rem);font-weight:900;color:var(--good);display:flex;align-items:center;gap:10px;margin:8px 0 0}.present-foot{display:flex;justify-content:space-between;align-items:flex-end}.present-count{font-size:1.6rem;color:var(--muted)}.present-count b{font-size:3rem;color:var(--ink)}.present-join{display:flex;align-items:center;gap:14px;font-size:1.2rem}.present-join b{font-size:2rem;letter-spacing:.15em;color:var(--brand)}.present-end{align-items:center;justify-content:center;gap:12px}.present-end .board{max-width:800px;font-size:1.6rem}.present-call .called-name{font-size:clamp(3rem,8vw,6rem);font-weight:900;margin:0}.study-intro ul{padding-left:20px}.fx-canvas{position:fixed;inset:0;width:100vw;height:100vh;pointer-events:none;z-index:90}.fx-float{position:fixed;z-index:91;transform:translate(-50%,-50%);pointer-events:none;font-weight:900;font-size:1.8rem;animation:floatUp 1.3s ease-out forwards;text-shadow:0 2px 0 rgba(0,0,0,.15);white-space:nowrap}.fx-xp{color:var(--good);font-size:2.4rem}.fx-tap{color:var(--brand);font-size:1.4rem}@keyframes floatUp{0%{opacity:0;transform:translate(-50%,-30%) scale(.6)}15%{opacity:1;transform:translate(-50%,-50%) scale(1.15)}to{opacity:0;transform:translate(-50%,-160%) scale(1)}}