:root{color-scheme:light;--paper:#FFFFFF;--paper-2:#EEF2F8;--paper-3:#F7F9FC;--ink:#0E2140;--ink-soft:#4B5A72;--faint:#7C8AA0;--line:#DDE3EC;--orange:#FC6B03;--india-green:#0F9A42;--blue:#1560C4;--yellow:#F2B90C;--red:#E0402A;--navy:#0E2140;--accent:var(--orange);--accent-ink:#C24405;--accent-soft:rgba(252,107,3,.1);--ok:#0F9A42;--ok-soft:rgba(15,154,66,.12);--bad:#E0402A;--bad-soft:rgba(224,64,42,.1);--c-axis:#C9D2DE;--c-grid:#EEF2F8;--c-num:#8A97AA;--c-a:#FC6B03;--c-a-bright:#FF7F24;--c-b:#0F9A42;--c-b2:#E0402A;--c-c:#1560C4;--c-ok:#0F9A42;--c-glow:rgba(252,107,3,.14);--muted:var(--ink-soft);--shadow:0 24px 60px -30px rgba(14,33,64,.28);--shadow-sm:0 10px 30px -18px rgba(14,33,64,.25);--ease:cubic-bezier(.22,1,.36,1);--r-card:16px;--r-btn:8px;--r-pill:100px;--maxw:1080px}:root[data-brand=learnacy]{--accent:#E0402A;--accent-ink:#C0311F;--accent-soft:rgba(224,64,42,.1);--c-a:#E0402A;--c-a-bright:#F0533F;--c-glow:rgba(224,64,42,.14);--c-b2:#FC6B03}:root[data-brand=g20]{--accent:#1560C4;--accent-ink:#0E4C9A;--accent-soft:rgba(21,96,196,.1);--c-a:#1560C4;--c-a-bright:#2C78DD;--c-glow:rgba(21,96,196,.14);--c-c:#FC6B03}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{margin:0;background:var(--paper);color:var(--ink);font-family:Hanken Grotesk,system-ui,-apple-system,sans-serif;font-size:17px;line-height:1.62;-webkit-font-smoothing:antialiased;overflow-x:hidden}h1,h2,h3{font-family:Fraunces,Fraunces,Georgia,serif;font-weight:600;margin:0;text-wrap:balance;letter-spacing:-.005em}p,li{text-wrap:pretty}.nb{white-space:nowrap}button{font:inherit;color:inherit}a{color:inherit;text-decoration:none}.mono{font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.app{min-height:100vh;min-height:100svh;display:flex;flex-direction:column}.top{position:sticky;top:0;z-index:20;background:#ffffffdb;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}.top-in{max-width:var(--maxw);margin:0 auto;padding:.7rem clamp(1rem,3vw,1.6rem);display:flex;align-items:center;gap:1rem}.wordmark{font-family:Fraunces,Georgia,serif;font-weight:700;font-size:1.25rem;letter-spacing:-.01em;cursor:pointer;display:inline-flex;align-items:baseline;gap:.35rem}.wordmark b{color:var(--accent-ink)}.wordmark small{font-family:Hanken Grotesk,sans-serif;font-weight:500;font-size:.78rem;color:var(--faint);margin-left:.4rem}.top-right{margin-left:auto;display:flex;align-items:center;gap:.5rem}.iconbtn svg{display:block}.main{flex:1;width:100%}.btn{font-family:Hanken Grotesk,sans-serif;font-size:15px;font-weight:600;padding:12px 22px;border-radius:var(--r-btn);cursor:pointer;border:1.5px solid transparent;display:inline-flex;align-items:center;gap:9px;transition:transform .25s var(--ease),background .25s,box-shadow .25s,color .2s,border-color .2s;white-space:nowrap;line-height:1.2}.btn-solid{background:var(--accent);color:var(--ink)}.btn-solid:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 14px 26px -12px color-mix(in srgb,var(--accent) 65%,transparent)}.btn-ghost{color:var(--ink);border-color:var(--ink);background:transparent}.btn-ghost:hover:not(:disabled){background:var(--ink);color:var(--paper)}.btn-quiet{color:var(--ink-soft);background:var(--paper-2);border-color:transparent}.btn-quiet:hover:not(:disabled){color:var(--ink);background:var(--line)}.btn:disabled{opacity:.38;cursor:default;transform:none;box-shadow:none}.btn .arr{transition:transform .25s var(--ease)}.btn:hover .arr{transform:translate(4px)}.btn-sm{font-size:13px;padding:8px 14px}.iconbtn{border:1px solid var(--line);background:var(--paper);border-radius:var(--r-pill);width:36px;height:36px;display:inline-grid;place-items:center;cursor:pointer;font-size:.95rem;color:var(--ink-soft);transition:.2s}.iconbtn:hover{border-color:var(--ink);color:var(--ink)}.iconbtn.on{background:var(--accent-soft);border-color:var(--accent);color:var(--accent-ink)}.eyebrow{font-size:.72rem;letter-spacing:.2em;text-transform:uppercase;font-weight:700;color:var(--accent-ink);display:inline-flex;align-items:center;gap:.6em}.eyebrow:before{content:"";width:22px;height:2px;background:var(--accent)}.chip{font-size:.72rem;font-weight:600;color:var(--ink-soft);border:1px solid var(--line);border-radius:var(--r-pill);padding:.3em .75em;display:inline-flex;gap:.4em;align-items:center;background:var(--paper)}.chip.accent{color:var(--accent-ink);border-color:color-mix(in srgb,var(--accent) 45%,var(--line));background:var(--accent-soft)}.chip.ok{color:var(--ok);border-color:color-mix(in srgb,var(--ok) 45%,var(--line));background:var(--ok-soft)}.home{max-width:var(--maxw);margin:0 auto;padding:clamp(1.4rem,4vw,3rem) clamp(1rem,3vw,1.6rem) 4rem}.hero{display:grid;gap:.9rem;max-width:720px;margin-bottom:2.2rem}.hero h1{font-size:clamp(2.1rem,5vw,3.4rem);line-height:1.04}.hero h1 em{font-style:italic;font-weight:600;color:var(--accent-ink)}.hero h1.triad{text-wrap:initial}.hero h1.triad span,.hero h1.triad em{display:block}.hero p{margin:0;color:var(--ink-soft);font-size:1.08rem;max-width:56ch}.sgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:1rem}.scard{position:relative;text-align:left;border:1px solid var(--line);border-radius:var(--r-card);background:var(--paper);padding:1.15rem 1.2rem 1.1rem;cursor:pointer;transition:transform .25s var(--ease),box-shadow .25s,border-color .2s;overflow:hidden;display:grid;gap:.45rem}.scard:before{content:"";position:absolute;left:0;top:0;bottom:0;width:5px;background:var(--sc,var(--accent))}.scard:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:color-mix(in srgb,var(--sc,var(--accent)) 40%,var(--line))}.scard h3{font-size:1.35rem;font-weight:600}.scard .sub{font-size:.86rem;color:var(--ink-soft)}.scard .prog{display:flex;align-items:center;gap:.6rem;margin-top:.3rem}.ring{width:34px;height:34px;border-radius:50%;background:conic-gradient(var(--sc,var(--accent)) calc(var(--p,0)*1%),var(--paper-2) 0);display:grid;place-items:center;flex:0 0 auto}.ring:after{content:"";width:24px;height:24px;border-radius:50%;background:var(--paper)}.prog small{font-size:.76rem;color:var(--faint);font-weight:600}.subj-head{display:flex;align-items:flex-end;gap:1rem;margin:0 0 1.2rem}.subj-head h2{font-size:clamp(1.7rem,3.6vw,2.4rem)}.topic-h{font-size:.7rem;letter-spacing:.16em;text-transform:uppercase;color:var(--faint);font-weight:700;margin:1.6rem 0 .7rem}.cgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:.9rem}.ccard{text-align:left;border:1px solid var(--line);border-radius:14px;background:var(--paper);padding:1rem 1.1rem;cursor:pointer;transition:transform .25s var(--ease),box-shadow .25s,border-color .2s;display:grid;gap:.4rem}.ccard:hover{transform:translateY(-2px);box-shadow:var(--shadow-sm);border-color:var(--ink)}.ccard.planned{cursor:default;opacity:.62}.ccard.planned:hover{transform:none;box-shadow:none;border-color:var(--line)}.ccard h4{font-family:Fraunces,serif;font-weight:600;font-size:1.12rem;margin:0;display:flex;align-items:center;gap:.4rem}.ccard p{margin:0;font-size:.9rem;color:var(--ink-soft);line-height:1.5}.ccard .meta{display:flex;gap:.4rem;flex-wrap:wrap;margin-top:.2rem}.star{color:var(--ok)}.stage-card{position:relative;border:1px solid var(--line);border-radius:var(--r-card);overflow:hidden;background:radial-gradient(110% 80% at 28% 30%,var(--c-glow) 0%,transparent 55%),var(--paper);box-shadow:var(--shadow-sm)}.stage-card canvas{position:absolute;inset:0;width:100%;height:100%;display:block;touch-action:none}.flash{position:absolute;inset:0;background:var(--ok);opacity:0;pointer-events:none;transition:opacity .4s}.flash.on{opacity:.14;transition:opacity .08s}.toast{position:absolute;top:14px;left:50%;transform:translate(-50%);background:var(--ok);color:#fff;padding:.45em 1em;border-radius:var(--r-pill);font-weight:700;font-size:.9rem;pointer-events:none;box-shadow:0 8px 22px -8px #00000059}.toast.bad{background:var(--bad)}.hintpill{position:absolute;left:14px;bottom:12px;background:#ffffffe6;border:1px solid var(--line);border-radius:var(--r-pill);padding:.35em .8em;font-size:.76rem;color:var(--ink-soft);display:flex;align-items:center;gap:.5em;pointer-events:none;backdrop-filter:blur(6px)}.hintpill i{width:7px;height:7px;border-radius:50%;background:var(--accent);animation:pulse 1.9s ease-in-out infinite}@keyframes pulse{0%,to{opacity:.35;transform:scale(.8)}50%{opacity:1;transform:scale(1.15)}}@media (prefers-reduced-motion:reduce){.hintpill i{animation:none}}.seg{display:inline-flex;background:var(--paper-2);border-radius:var(--r-pill);padding:4px;gap:2px;position:relative}.seg button{border:0;background:transparent;border-radius:var(--r-pill);padding:.5em 1.05em;font-size:.88rem;font-weight:600;color:var(--ink-soft);cursor:pointer;position:relative;z-index:1;transition:color .2s}.seg button.on{color:var(--ink)}.seg .pill{position:absolute;top:4px;bottom:4px;background:var(--paper);border-radius:var(--r-pill);box-shadow:0 2px 8px -2px #0e214040;z-index:0}.panel{border:1px solid var(--line);border-radius:var(--r-card);background:var(--paper);padding:1.2rem 1.35rem;box-shadow:var(--shadow-sm)}.ls-top{display:flex;align-items:center;gap:.8rem;margin-bottom:.9rem}.bar{flex:1;height:6px;border-radius:var(--r-pill);background:var(--paper-2);overflow:hidden}.bar i{display:block;height:100%;background:var(--accent);border-radius:var(--r-pill);transition:width .45s var(--ease)}.ls-count{font-family:ui-monospace,Menlo,monospace;font-size:.72rem;color:var(--faint);letter-spacing:.08em}.ls-tag{display:inline-block;font-size:.66rem;letter-spacing:.16em;text-transform:uppercase;color:var(--accent-ink);font-weight:700;margin-bottom:.45rem}.ls-text{font-size:clamp(1.06rem,1.7vw,1.22rem);line-height:1.6;color:var(--ink);max-width:64ch}.ls-text b{color:var(--accent-ink)}.opts{display:grid;gap:.55rem;margin-top:.9rem;max-width:64ch}.opt{text-align:left;border:1.5px solid var(--line);background:var(--paper);border-radius:12px;padding:.8em 1em;font-size:.98rem;cursor:pointer;transition:border-color .2s,background .2s,transform .2s var(--ease);display:flex;gap:.7em;align-items:flex-start;line-height:1.45}.opt .k{flex:0 0 auto;width:24px;height:24px;border-radius:50%;border:1.5px solid var(--line);display:grid;place-items:center;font-size:.72rem;font-weight:700;color:var(--ink-soft);margin-top:.05em}.opt:hover:not(:disabled){border-color:var(--ink);transform:translate(3px)}.opt:disabled{cursor:default}.opt.right{border-color:var(--ok);background:var(--ok-soft)}.opt.right .k{background:var(--ok);border-color:var(--ok);color:#fff}.opt.wrong{border-color:var(--bad);background:var(--bad-soft)}.opt.wrong .k{background:var(--bad);border-color:var(--bad);color:#fff}.why{margin-top:.9rem;padding:.9em 1.05em;border-radius:12px;background:var(--paper-2);font-size:.98rem;line-height:1.55;max-width:64ch}.why b{color:var(--ok)}.why.no b{color:var(--bad)}.why .sep{color:var(--faint)}.ls-done{display:grid;gap:.9rem}.ls-done .row{display:flex;gap:.6rem;flex-wrap:wrap}.readouts{display:flex;flex-wrap:wrap;gap:1.4rem 2rem}.ro .k{display:block;font-size:.64rem;letter-spacing:.15em;text-transform:uppercase;color:var(--faint);font-weight:700;margin-bottom:.2em}.ro .v{font-family:ui-monospace,Menlo,monospace;font-weight:600;font-size:1.45rem;font-variant-numeric:tabular-nums;color:var(--ink);display:inline-block;transition:transform .12s ease,color .12s}.ro .v.pop{transform:scale(1.14);color:var(--accent-ink)}.caption{font-family:Fraunces,serif;font-weight:500;font-size:clamp(1.08rem,1.8vw,1.28rem);line-height:1.5;color:var(--ink);max-width:64ch;margin-top:1rem}.caption b{color:var(--accent-ink)}.ch-prompt{font-family:Fraunces,serif;font-weight:500;font-size:clamp(1.12rem,1.9vw,1.36rem);line-height:1.45;color:var(--ink);max-width:64ch}.ch-prompt b{color:var(--accent-ink)}.ch-instruct{font-size:.9rem;color:var(--ink-soft);margin-top:.35rem}.ch-instruct .peek{color:var(--blue);font-family:ui-monospace,Menlo,monospace;font-size:.86rem}.countrow{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:1rem}.copt{border:1.5px solid var(--line);background:var(--paper);border-radius:10px;padding:.55em 1em;font-size:.92rem;font-weight:600;cursor:pointer;transition:.2s}.copt:hover{border-color:var(--ink)}.copt.sel{border-color:var(--accent);background:var(--accent-soft);color:var(--accent-ink)}.fields{display:flex;flex-wrap:wrap;gap:1rem 1.4rem;margin-top:1rem}.fld{display:grid;gap:.3rem}.fld .fl{font-size:.66rem;letter-spacing:.06em;text-transform:uppercase;color:var(--faint);font-weight:700}.stepper{display:inline-flex;align-items:center;border:1.5px solid var(--line);border-radius:10px;overflow:hidden;background:var(--paper);transition:border-color .2s}.stepper:focus-within{border-color:var(--accent)}.stepper button{border:0;background:none;width:2.2em;font-size:1.05rem;color:var(--accent-ink);cursor:pointer;padding:.4em 0}.stepper button:hover{background:var(--accent-soft)}.stepper input{font-family:ui-monospace,Menlo,monospace;font-weight:600;font-size:1.2rem;width:4em;text-align:center;font-variant-numeric:tabular-nums;color:var(--ink);border:0;border-left:1px solid var(--line);border-right:1px solid var(--line);padding:.35em .2em;background:none;outline:none}.ch-extra{display:flex;gap:.5rem;align-items:center;flex-wrap:wrap;margin-top:1rem}.tog{font-size:.8rem;font-weight:600;color:var(--ink-soft);cursor:pointer;border:1.5px solid var(--line);border-radius:var(--r-pill);padding:.4em .85em;background:var(--paper);transition:.2s}.tog.on{border-color:var(--accent);color:var(--accent-ink);background:var(--accent-soft)}.tog:disabled{opacity:.5;cursor:default}.pips{display:flex;gap:.35rem}.pips i{width:10px;height:10px;border-radius:50%;background:var(--accent);border:1.5px solid var(--accent)}.pips i.used{background:transparent;border-color:var(--line)}.verdict{font-weight:700;font-size:.95rem}.verdict.ok{color:var(--ok)}.verdict.no{color:var(--bad)}.progressline .lvl{color:var(--accent-ink);font-weight:700}.mdots{display:inline-flex;gap:.28rem}.mdots i{width:9px;height:9px;border-radius:50%;background:var(--line)}.mdots i.on{background:var(--accent)}.mastered{color:var(--ok);font-weight:700}.prove{border-top:1px dashed var(--line);margin-top:1.1rem;padding-top:1rem;display:grid;gap:.6rem}.prove .pq{font-size:.98rem}.prove .pq b{color:var(--blue)}.worked{margin-top:1rem;padding:.9em 1.05em;border-radius:12px;background:var(--paper-2);font-size:.95rem;line-height:1.55}.worked b{color:var(--ink)}.ex-simple{font-family:Fraunces,serif;font-size:1.12rem;line-height:1.5}.ex-row{font-size:.94rem;color:var(--ink-soft)}.ex-row b,.ex-try b{color:var(--accent-ink)}.ex-try{font-size:.92rem}.terms{display:flex;flex-wrap:wrap;gap:.4rem}.term{font-size:.76rem;border:1px solid var(--line);border-radius:8px;padding:.3em .65em;background:var(--paper);cursor:help}.term b{color:var(--blue)}.related{display:flex;gap:.6rem;flex-wrap:wrap}.rlink{border:1px solid var(--line);border-radius:12px;background:var(--paper);padding:.6em .9em;text-align:left;cursor:pointer;display:grid;gap:.15em;transition:.2s}.rlink:hover{border-color:var(--ink);transform:translateY(-1px)}.rlink small{font-family:ui-monospace,Menlo,monospace;font-size:.62rem;color:var(--faint);letter-spacing:.05em}@media (max-width:640px){.top-in{gap:.6rem}.wordmark small{display:none}}:root{--top-h:56px;--ctl-w:400px;--hud-h:40px;--lab-maxw:1680px;--lab-x:16px;--svh:100vh;--ok-ink:#0A7A34;--bad-ink:#C2331F }@supports (height:100svh){:root{--svh:100svh }}@media (min-width:1024px) and (max-width:1279px){:root{--ctl-w:380px }}@media (min-width:1600px){:root{--ctl-w:420px }}@media (min-width:1920px){:root{--ctl-w:440px }}@media (max-width:1023px),(orientation:portrait){:root{--hud-h:36px }}@media (max-width:640px){:root{--top-h:48px;--hud-h:30px }}.top{height:calc(var(--top-h) + env(safe-area-inset-top,0px));padding-top:env(safe-area-inset-top,0px)}.top-in{height:100%;padding-top:0;padding-bottom:0}html.lab-route,html.lab-route body{height:100%;overflow:hidden;overscroll-behavior:none}.app.in-lab{height:var(--vvh,var(--svh));min-height:0;overflow:hidden;overscroll-behavior:none}.app.in-lab .main{flex:1 1 auto;min-height:0;display:flex;flex-direction:column}.app.in-lab .top-in{max-width:var(--lab-maxw);padding-left:var(--lab-x);padding-right:var(--lab-x)}@media (max-width:640px){.app.in-lab .wordmark{font-size:1.1rem}.app.in-lab .top-right .iconbtn{width:32px;height:32px}}.lab{--t-prompt:1.08rem;--t-text:1rem;--t-opt:.9rem;--t-body:.88rem;--t-small:.84rem;position:relative;width:100%;max-width:var(--lab-maxw);margin:0 auto;flex:1 1 auto;min-height:0;padding:10px var(--lab-x) 12px;overflow:hidden;display:grid;gap:10px 16px;grid-template-columns:minmax(0,1fr) var(--ctl-w);grid-template-rows:auto minmax(0,1fr) var(--hud-h);grid-template-areas:"title tabs" "stage ctl" "hud ctl"}.lab-title{grid-area:title}.ctl-tabs{grid-area:tabs}.stage-wrap{grid-area:stage}.hud{grid-area:hud}.ctl{grid-area:ctl}@media (min-width:1024px) and (min-height:860px){.lab{--t-prompt:1.2rem;--t-text:1.08rem;--t-opt:.96rem;--t-body:.92rem;--t-small:.88rem}}.lab-title{display:flex;align-items:center;gap:10px;min-width:0;min-height:36px}.lab-title h1{flex:1 1 auto;min-width:0;font-size:1.35rem;line-height:1.15;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;text-wrap:auto}.lab-title .chips{display:flex;gap:6px;flex:0 0 auto}.lab-title .back .back-i{display:none}.lab-title .about-i{display:none;flex:0 0 auto;font-family:Fraunces,Georgia,serif;font-style:italic;font-weight:600}@media (max-width:1279px){.lab-title .chip.diff{display:none}}.ctl-tabs.seg{display:flex;width:100%;padding:3px;min-width:0;align-self:center}.ctl-tabs.seg button{flex:1 1 0;text-align:center;line-height:1.2;padding:.45em .6em;min-height:30px}.ctl-tabs.seg .pill{top:3px;bottom:3px}.stage-wrap{min-width:0;min-height:0;container-type:size;display:grid;place-items:center}.lab .stage-card{aspect-ratio:auto;width:min(100cqw,200cqh);height:min(100cqh,80cqw)}@supports not (width:1cqw){.lab .stage-card{width:100%;height:100%}}.hud{min-width:0;align-self:start;height:var(--hud-h);display:flex;align-items:center;gap:22px;padding:0 6px;overflow-x:auto;overflow-y:hidden;white-space:nowrap;scrollbar-width:none}.hud::-webkit-scrollbar{display:none}.hud .ro{display:grid;gap:1px;flex:0 0 auto}.hud .ro .k{font-size:.6rem;letter-spacing:.12em;line-height:1.2;margin:0}.hud .ro .v{font-size:.95rem;line-height:1.25}.hud .status{display:flex;align-items:center;gap:.6rem;flex:1 1 auto;min-width:max-content;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.74rem;color:var(--ink-soft)}.hud .status .lvl{color:var(--accent-ink);font-weight:700}.hud .status .score{margin-left:auto;padding-left:1rem}.ctl{position:relative;display:flex;flex-direction:column;gap:8px;min-height:0;min-width:0}.ctl-panel{flex:1 1 auto;min-height:0;display:flex;flex-direction:column}.ctl-panel>.panel{flex:1 1 auto;min-height:0;display:flex;flex-direction:column;padding:14px 16px}.mode-body{flex:1 1 auto;min-height:0;overflow-y:auto;overflow-x:hidden;overscroll-behavior:contain;touch-action:pan-y;scrollbar-width:thin;margin-right:-6px;padding-right:6px}.mode-foot{flex:0 0 auto;display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding-top:10px}.mode-foot .pips{margin-left:auto}.mode-foot .muted{font-size:.8rem;color:var(--faint)}.ctl-foot{flex:0 0 auto;min-height:33px;display:flex;align-items:center;gap:8px}.ctl-foot .spacer{flex:1}.ctl-overlay{position:absolute;inset:0;z-index:5;display:flex;flex-direction:column;overflow:hidden;background:var(--paper-3);border:1px solid var(--line);border-radius:var(--r-card);box-shadow:var(--shadow-sm)}.ov-h{flex:0 0 auto;display:flex;align-items:center;gap:8px;padding:10px 12px 10px 16px;border-bottom:1px solid var(--line);font-weight:600;font-size:.95rem}.ov-h .iconbtn{margin-left:auto;width:32px;height:32px}.ov-b{flex:1 1 auto;min-height:0;overflow-y:auto;overscroll-behavior:contain;touch-action:pan-y;padding:14px 16px 18px;display:grid;gap:10px;align-content:start}.ov-scrim{display:none}.lab .ex-simple{font-size:1rem;line-height:1.5}.lab .ex-row,.lab .ex-try{font-size:var(--t-body);line-height:1.5}.lab .ov-b .topic-h{margin:8px 0 0}.mode-body.col{display:flex;flex-direction:column}.mode-body.col>*{flex:0 0 auto}.about-inline{margin-top:auto;padding-top:12px;border-top:1px dashed var(--line);display:grid;gap:6px}.about-inline>:first-child{margin-top:14px}.about-inline .ls-tag{color:var(--faint);margin:0}.about-inline .ex-simple{font-size:var(--t-body);color:var(--ink-soft)}.lab .btn{padding:10px 18px}.lab .btn-sm{padding:7px 12px}.lab .ch-prompt{font-size:var(--t-prompt);line-height:1.4;max-width:none;overflow-wrap:anywhere}.lab .ch-instruct{font-size:var(--t-small);line-height:1.45;margin-top:6px;overflow-wrap:anywhere}.lab .ch-instruct .peek{font-size:.8rem}.lab .countrow{margin-top:10px;gap:6px}.lab .copt{font-size:.86rem;line-height:1.25;padding:.45em .8em;border-radius:8px}.lab .copt:disabled{cursor:default}.lab .copt:disabled:not(.sel){opacity:.55}.lab .copt.sel:disabled{opacity:1}.lab .fields{margin-top:10px;gap:8px 12px}.lab .fld{gap:4px}.lab .fld .fl{line-height:1.4;text-transform:none;letter-spacing:.02em;font-size:.7rem}.lab .stepper{height:36px;border-radius:8px}.lab .stepper button{width:30px;height:100%;padding:0;font-size:1rem;line-height:1}.lab .stepper input{width:3.2em;height:100%;padding:0 4px;font-size:1.05rem;line-height:1.2}.lab .stepper input:disabled,.lab .stepper button:disabled{opacity:.6;cursor:default}.bits{display:flex;gap:6px;margin-top:10px;flex-wrap:wrap}.bit{display:grid;gap:4px;justify-items:center}.bit .fl{font-size:.62rem;letter-spacing:.04em;line-height:1.4;color:var(--faint);font-weight:700}.bit button{width:36px;height:36px;border:1.5px solid var(--line);border-radius:8px;background:var(--paper);font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-weight:700;font-size:1rem;color:var(--ink-soft);cursor:pointer;transition:.2s}.bit button[aria-pressed=true]{border-color:var(--accent);background:var(--accent-soft);color:var(--accent-ink)}.bit button:disabled{cursor:default;opacity:.7}.lab .ch-extra{margin-top:10px;gap:6px}.lab .tog{font-size:.78rem;line-height:1.2;padding:.4em .8em}.lab .verdict{display:block;margin-top:8px;font-size:var(--t-body);line-height:1.45}.lab .prove{margin-top:12px;padding-top:10px;gap:8px;overflow:hidden}.lab .prove .pq{font-size:.92rem;line-height:1.45}.lab .prove .fields{margin-top:0}.lab .worked{margin-top:10px;padding:10px 12px;font-size:var(--t-body);line-height:1.5;overflow-wrap:anywhere}.lab .ls-top{margin-bottom:10px}.lab .ls-tag{display:block;line-height:1.4;margin-bottom:6px}.lab .ls-text{font-size:var(--t-text);line-height:1.5;max-width:none}.lab .opts{margin-top:10px;gap:6px;max-width:none}.lab .opts.two{grid-template-columns:1fr 1fr}.lab .opt{font-size:var(--t-opt);line-height:1.4;padding:.55em .8em;border-radius:10px;gap:.55em}.lab .opt .k{width:20px;height:20px;font-size:.66rem;margin-top:0}.lab .opt:hover:not(:disabled){transform:none}.lab .why{margin-top:10px;padding:9px 12px;font-size:var(--t-body);line-height:1.45;max-width:none}.lab .ls-done{gap:8px}.lab .caption{font-size:1.15rem;line-height:1.45;margin-top:0;max-width:none}.lab .ex-try.lead{margin-top:10px;padding:8px 12px;border-radius:10px;background:var(--accent-soft)}@media (pointer:coarse){.ctl-tabs.seg button{min-height:34px}.lab .stepper{height:40px}.lab .stepper button{width:36px}.lab .copt,.lab .tog{padding:.55em .9em}.bit button{width:38px;height:38px}}@media (max-width:1023px),(orientation:portrait){.lab{--stage-h:clamp(200px, calc(var(--vvh,var(--svh)) - var(--top-h) - 18px - 36px - 32px - var(--hud-h) - 40px - 250px), calc((100vw - 24px)/2) );padding:8px 12px calc(10px + env(safe-area-inset-bottom,0px));gap:8px;grid-template-columns:minmax(0,1fr);grid-template-rows:36px var(--stage-h) var(--hud-h) 40px minmax(0,1fr);grid-template-areas:"title" "stage" "hud" "tabs" "ctl"}.lab-title .about-i{display:inline-grid}.ctl-foot,.about-inline{display:none}.stage-wrap{container-type:normal;display:block;overflow:hidden}.lab .stage-card{width:100%;height:100%;transition:height .16s var(--ease)}.ctl-tabs.seg button{min-height:34px}.lab .countrow.two{display:grid;grid-template-columns:1fr 1fr}.lab .stepper button{width:34px}.lab .mode-foot{padding-top:8px}.hintpill{inset:8px 8px auto auto;max-width:calc(100% - 16px);white-space:nowrap;overflow:hidden;font-size:.7rem;padding:.3em .7em}.toast{top:auto;bottom:10px;font-size:.82rem}.ctl-overlay{position:fixed;inset:auto 0 0;height:auto;max-height:70svh;z-index:30;border-radius:16px 16px 0 0;border-bottom:0;padding-bottom:env(safe-area-inset-bottom,0px)}.ov-scrim{display:block;position:fixed;inset:0;z-index:29;background:#0e214040}.lab.kbd{grid-template-rows:0 0 0 0 minmax(0,1fr);gap:0}.lab.kbd>:not(.ctl){overflow:hidden;visibility:hidden}}@media (prefers-reduced-motion:reduce){.lab .stage-card{transition:none}}@media (max-width:640px){.lab{--stage-h:clamp(200px, calc(var(--vvh,var(--svh)) - var(--top-h) - 12px - 30px - 24px - var(--hud-h) - 40px - 250px), calc((100vw - 20px)/1.6) );padding:6px 10px calc(6px + env(safe-area-inset-bottom,0px));gap:6px;grid-template-rows:30px var(--stage-h) var(--hud-h) 40px minmax(0,1fr)}.lab-title{gap:8px;min-height:0}.lab-title h1{font-size:1.05rem;line-height:1.2}.lab-title .back{padding:0;width:28px;height:28px;justify-content:center;border-radius:var(--r-pill)}.lab-title .back .back-txt{display:none}.lab-title .back .back-i{display:inline;font-size:1.2rem;line-height:1}.lab-title .chip.diff,.lab-title .chip .long{display:none}.lab-title .iconbtn{width:28px;height:28px}.lab .stage-card{border-radius:12px}.hud{gap:14px;padding:0 4px}.hud .ro .k{font-size:.56rem}.hud .ro .v{font-size:.8rem;line-height:1.2}.hud .status{font-size:.68rem}.hud .status .long{display:none}.ctl-panel>.panel{padding:12px;border-radius:12px}.lab .btn{padding:10px 16px}.bits{gap:5px}.bit button{width:34px;height:34px}.lab .stepper input{width:3em}}@media (max-width:640px) and (max-height:620px) and (orientation:portrait){.lab{gap:4px}.lab[data-mode=play]:not(.kbd){grid-template-rows:30px var(--stage-h) 0 40px minmax(0,1fr)}.lab[data-mode=play] .hud{display:none}}@media (max-height:500px) and (orientation:landscape){:root{--top-h:40px;--hud-h:30px }.lab{padding:6px max(10px,env(safe-area-inset-right,0px)) 6px max(10px,env(safe-area-inset-left,0px));gap:6px 10px;grid-template-columns:minmax(0,1fr) 300px;grid-template-rows:36px minmax(0,1fr) var(--hud-h);grid-template-areas:"stage tabs" "stage ctl" "hud ctl"}.lab-title{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;min-height:0;padding:0}.lab-title .back,.lab-title .chips,.lab-title .about-i{display:none}.ctl-foot{display:flex;min-height:28px}.ctl-foot .back-l{display:inline-flex}.stage-wrap{container-type:size;display:grid}.lab .stage-card{width:min(100cqw,200cqh);height:min(100cqh,80cqw);transition:none}.ctl-overlay{position:absolute;inset:0;max-height:none;border-radius:var(--r-card);border-bottom:1px solid var(--line);padding-bottom:0}.ov-scrim{display:none}.lab.kbd{grid-template-columns:0 minmax(0,1fr);grid-template-rows:0 minmax(0,1fr) 0;gap:0}.lab.kbd>:not(.ctl){visibility:hidden}}.verdict.ok,.mastered,.chip.ok,.why b{color:var(--ok-ink)}.verdict.no,.why.no b{color:var(--bad-ink)}.toast{background:var(--ok-ink)}.toast.bad{background:var(--bad-ink)}.hud .ro .k,.mode-foot .muted,.bit .fl,.about-inline .ls-tag{color:var(--ink-soft)}.hintpill span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.rlink:disabled{opacity:.55;cursor:default}.rlink:disabled:hover{transform:none;border-color:var(--line)}.ls-card{outline:none}.terms-wrap{display:grid;gap:6px}button.term{font:inherit;font-size:.76rem;line-height:1.4;cursor:pointer;color:inherit}.term.on{border-color:var(--blue);background:#1560c40f}.term-def{font-size:var(--t-body,.9rem);color:var(--ink-soft);line-height:1.45}.term-def b{color:var(--blue)}.back-l{display:none}.stage-card canvas:focus-visible{outline:2px solid var(--accent);outline-offset:-2px}.ctl-panel>.panel{position:relative}.calc{position:absolute;left:10px;right:10px;bottom:62px;z-index:6;background:var(--paper);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:10px;display:grid;gap:8px}.calc-top{display:flex;align-items:center;gap:8px}.calc-tag{font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;font-weight:700;color:var(--ink-soft);flex:1}.calc-top .iconbtn{width:28px;height:28px}.calc-in{font:inherit;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:1rem;padding:8px 10px;border:1.5px solid var(--line);border-radius:8px;background:var(--paper);color:var(--ink);outline:none}.calc-in:focus{border-color:var(--accent)}.calc-out{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:1.25rem;font-weight:600;color:var(--ink);text-align:right;padding:0 4px;min-height:1.5em;font-variant-numeric:tabular-nums}.calc-out.err{color:var(--bad-ink);font-size:.85rem;font-weight:500}.calc-keys{display:grid;grid-template-columns:repeat(5,1fr);gap:5px}.ck{font:inherit;font-size:.86rem;font-weight:600;padding:7px 0;border:1px solid var(--line);border-radius:7px;background:var(--paper-3);color:var(--ink-soft);cursor:pointer;transition:.15s}.ck:hover{border-color:var(--ink);color:var(--ink)}.ck.num{background:var(--paper);color:var(--ink);font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.ck.eq{background:var(--accent);border-color:var(--accent);color:var(--ink)}.calc-foot{display:flex;justify-content:flex-end}@media (max-width:640px){.calc{left:6px;right:6px;bottom:58px}.ck{padding:9px 0}}.beatrow{display:flex;align-items:center;gap:5px;margin-bottom:8px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.7rem;color:var(--ink-soft)}.beatrow i{width:18px;height:6px;border-radius:3px;background:var(--line)}.beatrow i.on{background:var(--accent)}.beatrow i.done{background:var(--ok)}.beatrow span{margin-left:6px}.canvas-cue{color:var(--accent-ink);font-weight:600}