:root{
  --ink:#1B2540; --ink-2:#4A5570; --ink-3:#7A849B;
  --paper:#F3F5F8; --card:#FFFFFF; --line:#DDE2EA; --soft:#E9EDF3;
  --track:#2E5BFF;
  --g:#1F8A5B; --g-bg:#E3F4EC;
  --a:#C98A10; --a-bg:#FBF1DC;
  --r:#C23B36; --r-bg:#F9E4E2;
  --focus:#2E5BFF;
  --lv1:#0E7C6B; --lv1-bg:#DDF3EE; --lv2:#5B3FD1; --lv2-bg:#ECE7FC; --lv3:#C2410C; --lv3-bg:#FDE9DD; --hot:#E8590C; --bad:#C23B36;
  --radius:10px;
  box-sizing:border-box;
  padding-top:env(safe-area-inset-top,0px);
  padding-bottom:env(safe-area-inset-bottom,0px);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --ink:#E8ECF5; --ink-2:#B3BBCD; --ink-3:#8590A8;
    --paper:#10152A; --card:#182038; --line:#2A3452; --soft:#1F2845;
    --track:#7C9BFF;
    --g:#4CC38A; --g-bg:#16342A; --a:#F0B84A; --a-bg:#3A2E14; --r:#F07A74; --r-bg:#3B1C1C; --focus:#7C9BFF; --lv1:#4FD1B5; --lv1-bg:#123530; --lv2:#A897FF; --lv2-bg:#2A2450; --lv3:#FB9A5E; --lv3-bg:#3D2414; --hot:#FF8A3D; --bad:#F07A74;
  }
}
:root[data-theme="dark"]{
  --ink:#E8ECF5; --ink-2:#B3BBCD; --ink-3:#8590A8;
  --paper:#10152A; --card:#182038; --line:#2A3452; --soft:#1F2845;
  --track:#7C9BFF;
  --g:#4CC38A; --g-bg:#16342A; --a:#F0B84A; --a-bg:#3A2E14; --r:#F07A74; --r-bg:#3B1C1C; --focus:#7C9BFF; --lv1:#4FD1B5; --lv1-bg:#123530; --lv2:#A897FF; --lv2-bg:#2A2450; --lv3:#FB9A5E; --lv3-bg:#3D2414; --hot:#FF8A3D; --bad:#F07A74;
}
*,*::before,*::after{box-sizing:inherit}
html{height:100%;scroll-padding-top:env(safe-area-inset-top,0px)}
body{margin:0;min-height:100%;background:var(--paper);color:var(--ink);font-family:"Figtree",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;font-size:16px;line-height:1.55;-webkit-font-smoothing:antialiased}
button,input,textarea,select{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px;border-radius:6px}
a{color:var(--track)}
img{max-width:100%}

/* shell */
.app{display:grid;grid-template-columns:232px 1fr;min-height:100vh}
.side{position:sticky;top:env(safe-area-inset-top,0px);align-self:start;height:100vh;padding:24px 16px;border-right:1px solid var(--line);display:flex;flex-direction:column;gap:4px}
.brand{font-weight:800;font-size:1.15rem;letter-spacing:-.01em;padding:0 10px 18px;display:flex;align-items:center;gap:8px}
.brand svg{flex:none}
.nav-btn{display:flex;align-items:center;gap:12px;width:100%;border:0;background:none;padding:10px 12px;border-radius:8px;cursor:pointer;text-align:left;font-weight:500;color:var(--ink-2)}
.nav-btn:hover{background:var(--soft)}
.nav-btn[aria-current="page"]{background:var(--ink);color:var(--paper)}
.nav-btn svg{flex:none}
.side-foot{margin-top:auto;font-size:.8rem;color:var(--ink-3);padding:0 12px}
main{padding:32px clamp(16px,4vw,48px) 96px;max-width:980px;width:100%}
.bottom-nav{display:none}

@media (max-width:760px){
  .app{grid-template-columns:1fr}
  .side{display:none}
  main{padding:20px 16px 110px}
  .bottom-nav{display:grid;grid-template-columns:repeat(5,1fr);position:fixed;left:0;right:0;bottom:0;background:var(--card);border-top:1px solid var(--line);padding:6px 4px calc(6px + env(safe-area-inset-bottom,0px));z-index:20}
  .bottom-nav .nav-btn{flex-direction:column;gap:2px;font-size:.7rem;padding:6px 2px;justify-content:center;align-items:center;text-align:center}
  .bottom-nav .nav-btn[aria-current="page"]{background:none;color:var(--track)}
}

/* type */
h1{font-size:clamp(1.6rem,4vw,2.2rem);line-height:1.15;letter-spacing:-.02em;margin:0 0 8px;font-weight:800}
h2{font-size:1.25rem;margin:32px 0 12px;letter-spacing:-.01em}
h3{font-size:1.05rem;margin:0 0 6px}
.lede{color:var(--ink-2);margin:0 0 24px;max-width:62ch}
.muted{color:var(--ink-3)}
.small{font-size:.875rem}

/* components */
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px}
.btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:var(--card);padding:8px 14px;border-radius:8px;cursor:pointer;font-weight:600;font-size:.92rem}
.btn:hover{border-color:var(--ink-3)}
.btn.primary{background:var(--track);border-color:var(--track);color:#fff}
.btn.ghost{background:none;border-color:transparent}
.btn.ghost:hover{background:var(--soft)}
.btn:disabled{opacity:.5;cursor:default}
.chip{display:inline-flex;align-items:center;gap:6px;font-size:.78rem;font-weight:600;padding:2px 9px;border-radius:999px;white-space:nowrap}
.lv-basic{background:var(--lv1-bg);color:var(--lv1)}
.lv-medium{background:var(--lv2-bg);color:var(--lv2)}
.lv-hard{background:var(--lv3-bg);color:var(--lv3)}
.rag-g{background:var(--g-bg);color:var(--g)}.rag-a{background:var(--a-bg);color:var(--a)}.rag-r{background:var(--r-bg);color:var(--r)}
.dot{width:8px;height:8px;border-radius:50%;display:inline-block}
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:18px}
.tab{border:1px solid var(--line);background:var(--card);border-radius:999px;padding:6px 14px;cursor:pointer;font-weight:600;font-size:.88rem;color:var(--ink-2)}
.tab[aria-pressed="true"]{background:var(--ink);color:var(--paper);border-color:var(--ink)}
input[type=text],input[type=date],textarea,select{width:100%;border:1px solid var(--line);background:var(--card);border-radius:8px;padding:9px 11px}
textarea{min-height:110px;resize:vertical;line-height:1.5}
label.fld{display:block;font-size:.85rem;font-weight:600;color:var(--ink-2);margin-bottom:4px}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.stack>*+*{margin-top:12px}
.grid2{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px}
.empty{border:1px dashed var(--line);border-radius:var(--radius);padding:28px;text-align:center;color:var(--ink-3)}
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);background:var(--ink);color:var(--paper);padding:10px 16px;border-radius:8px;font-weight:600;font-size:.9rem;z-index:50;opacity:0;pointer-events:none;transition:opacity .2s}
.toast.show{opacity:1}
@media (max-width:760px){.toast{bottom:calc(84px + env(safe-area-inset-bottom,0px))}}

/* critical path (signature element) */
.path-wrap{overflow-x:auto;margin:0 -4px 8px;padding:4px}
.path{position:relative;display:flex;align-items:flex-start;min-width:720px;padding:34px 8px 8px}
.path::before{content:"";position:absolute;left:18px;right:18px;top:48px;height:3px;background:var(--line);border-radius:2px}
.path .fill{position:absolute;left:18px;top:48px;height:3px;background:var(--track);border-radius:2px;transition:width .6s ease}
.node{position:relative;flex:1;display:flex;flex-direction:column;align-items:center;gap:6px;background:none;border:0;cursor:pointer;padding:0;z-index:1}
.node .pip{width:14px;height:14px;border-radius:50%;background:var(--card);border:3px solid var(--line);margin-top:1px}
.node.done .pip{background:var(--track);border-color:var(--track)}
.node.next .pip{border-color:var(--track);box-shadow:0 0 0 5px color-mix(in srgb,var(--track) 20%,transparent)}
.node.gate-node .pip{width:22px;height:22px;border-radius:4px;transform:rotate(45deg);margin-top:-3px}
.node .lbl{font-size:.68rem;color:var(--ink-3);max-width:62px;text-align:center;line-height:1.2}
.node.gate-node .lbl{font-weight:700;color:var(--ink-2);position:absolute;top:-30px;white-space:nowrap;max-width:none}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-top:16px}
.stat{padding:14px 16px;border-left:3px solid var(--line);background:var(--card);border-radius:0 8px 8px 0}
.stat b{display:block;font-size:1.5rem;letter-spacing:-.02em}
.stat.basic{border-color:var(--lv1)} .stat.medium{border-color:var(--lv2)} .stat.hard{border-color:var(--lv3)}

/* lesson list */
.lvl-head{display:flex;align-items:baseline;gap:12px;margin:28px 0 10px}
.lvl-head h2{margin:0}
.lesson-row{display:flex;align-items:center;gap:14px;padding:14px 16px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);cursor:pointer;width:100%;text-align:left;margin-bottom:8px}
.lesson-row:hover{border-color:var(--ink-3)}
.check{width:22px;height:22px;border-radius:50%;border:2px solid var(--line);flex:none;display:grid;place-items:center}
.check.on{background:var(--track);border-color:var(--track);color:#fff}
.lesson-row .t{flex:1;min-width:0}
.lesson-row .t b{display:block;font-weight:600}

/* lesson detail */
.back{margin-bottom:14px}
.points{padding-left:1.2em;margin:0}
.points li{margin-bottom:8px}
.quiz-opt{display:block;width:100%;text-align:left;border:1px solid var(--line);background:var(--card);border-radius:8px;padding:10px 12px;margin-bottom:8px;cursor:pointer}
.quiz-opt.right{border-color:var(--g);background:var(--g-bg)}
.quiz-opt.wrong{border-color:var(--r);background:var(--r-bg)}
.callout{border-left:3px solid var(--track);padding:10px 14px;background:var(--soft);border-radius:0 8px 8px 0}

/* cheat sheets */
.sheet{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);margin-bottom:10px;overflow:hidden}
.sheet summary{cursor:pointer;padding:14px 16px;font-weight:700;list-style:none;display:flex;align-items:center;gap:10px}
.sheet summary::-webkit-details-marker{display:none}
.sheet summary::after{content:"+";margin-left:auto;font-weight:600;color:var(--ink-3);font-size:1.2rem}
.sheet[open] summary::after{content:"–"}
.sheet .body{padding:0 16px 16px}
.tbl-wrap{overflow-x:auto}
table{border-collapse:collapse;width:100%;font-size:.9rem}
th,td{text-align:left;padding:8px 10px;border-bottom:1px solid var(--line);vertical-align:top}
th{color:var(--ink-2);font-weight:700}
pre.tpl{white-space:pre-wrap;background:var(--soft);padding:12px;border-radius:8px;font-family:ui-monospace,"SF Mono",Menlo,Consolas,monospace;font-size:.84rem;margin:8px 0 0;overflow-x:auto}

/* projects */
.proj{display:flex;flex-direction:column;gap:8px;cursor:pointer;text-align:left;width:100%}
.proj:hover{border-color:var(--ink-3)}
.ai-out{white-space:pre-wrap;background:var(--soft);border-radius:8px;padding:14px;font-size:.93rem}

/* tasks */
.board{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
@media (max-width:760px){.board{grid-template-columns:1fr}}
.col{background:var(--soft);border-radius:var(--radius);padding:10px;min-height:120px}
.col h3{font-size:.9rem;display:flex;align-items:center;gap:8px;padding:4px 6px 10px;margin:0}
.task{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:10px 12px;margin-bottom:8px}
.task .tt{font-weight:600;word-break:break-word}
.task .meta{font-size:.78rem;color:var(--ink-3);margin-top:4px;display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.task .acts{display:flex;gap:4px;margin-top:8px;flex-wrap:wrap}
.task .acts .btn{padding:4px 9px;font-size:.8rem}
.overdue{color:var(--r);font-weight:600}

/* discuss */
.thread{display:block;width:100%;text-align:left;cursor:pointer;margin-bottom:8px}
.thread:hover{border-color:var(--ink-3)}
.post-body{white-space:pre-wrap;word-break:break-word}
.reply{border-left:2px solid var(--line);padding:6px 0 6px 14px;margin:10px 0}
.who{font-weight:600;font-size:.88rem}

@media (prefers-reduced-motion:reduce){*{transition:none!important}}

.node.lv-node-basic .pip{border-color:var(--lv1)} .node.lv-node-medium .pip{border-color:var(--lv2)} .node.lv-node-hard .pip{border-color:var(--lv3)}
.node.lv-node-basic.done .pip{background:var(--lv1)} .node.lv-node-medium.done .pip{background:var(--lv2)} .node.lv-node-hard.done .pip{background:var(--lv3)}
.lvl-head h2{display:flex;align-items:center;gap:10px;font-size:1rem;font-weight:600;color:var(--ink-2)}
.lvl-head h2 .chip{font-size:.95rem;padding:4px 12px}
.gate{min-height:70vh;display:grid;place-items:center}
.dash{display:grid;grid-template-columns:minmax(220px,1fr) 2fr;gap:12px}
@media (max-width:760px){.dash{grid-template-columns:1fr}}
.big{font-size:2rem;font-weight:800;letter-spacing:-.03em}
.strip{display:grid;grid-template-columns:repeat(14,1fr);gap:4px;margin-top:14px}
.day{aspect-ratio:1;border-radius:4px;background:var(--soft);border:1px solid var(--line)}
.day.l1{background:color-mix(in srgb,var(--hot) 30%,var(--card));border-color:transparent}
.day.l2{background:color-mix(in srgb,var(--hot) 60%,var(--card));border-color:transparent}
.day.l3{background:var(--hot);border-color:transparent}
.goal+.goal{margin-top:12px}
.bar{height:8px;background:var(--soft);border-radius:4px;overflow:hidden;margin-top:4px}
.bar span{display:block;height:100%;background:var(--track);border-radius:4px;transition:width .5s}
.hit{color:var(--lv1);font-weight:700}
input[type=number],input[type=password]{width:100%;border:1px solid var(--line);background:var(--card);border-radius:8px;padding:9px 11px}
.example{white-space:pre-wrap;background:var(--card);border:1px solid var(--line);border-left:3px solid var(--lv2);border-radius:0 var(--radius) var(--radius) 0;padding:14px 16px;line-height:1.6}
.flash{margin:14px auto 0;max-width:620px;min-height:240px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:26px;display:flex;flex-direction:column;justify-content:center;gap:18px;cursor:pointer;box-shadow:0 1px 0 var(--line),0 8px 0 -4px var(--soft),0 9px 0 -4px var(--line)}
.flash .fq{font-size:1.3rem;font-weight:700;margin:4px 0 0;line-height:1.35}
.flash .face.back{border-top:1px dashed var(--line);padding-top:16px}
.flash .fa{font-size:1.05rem;margin:4px 0 0}
.flash.flipped{cursor:default}
.btn.again{border-color:var(--bad);color:var(--bad)}
.boxes{display:grid;grid-template-columns:repeat(6,1fr);gap:8px}
.boxcol{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:12px 8px;text-align:center}
.boxcol b{display:block;font-size:1.3rem}
.grid4{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px}
.timer{font-size:1.4rem;font-weight:800;font-variant-numeric:tabular-nums;padding:4px 12px;border-radius:8px;background:var(--soft)}
.timer.low{background:var(--r-bg);color:var(--r)}
.btn.small{padding:4px 10px;font-size:.84rem}
.panel.thread .row svg{flex:none;color:var(--track)}

.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.img-prev img{max-height:180px;border-radius:8px;border:1px solid var(--line);margin:6px 0}
.deep h3{margin:18px 0 4px}
.deep p{margin:0;color:var(--ink-2);max-width:68ch}
.mistakes{list-style:none;padding:0;margin:0}
.mistakes li{position:relative;padding:8px 0 8px 30px;border-bottom:1px solid var(--line)}
.mistakes li::before{content:"✕";position:absolute;left:4px;top:8px;width:18px;height:18px;border-radius:50%;background:var(--r-bg);color:var(--r);font-size:.7rem;font-weight:800;display:grid;place-items:center}
/* diagrams */
.diagram{margin:18px 0 0;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:18px 16px 14px;display:flex;flex-direction:column;gap:18px}
.diagram img{display:block;margin:0 auto;border-radius:8px}
.diagram figcaption{font-size:.86rem;color:var(--ink-2);border-top:1px solid var(--line);padding-top:10px}
.d-svg{width:100%;max-width:540px;height:auto;display:block;margin:0 auto;font-family:inherit;overflow:visible}
.d-svg text{fill:var(--ink);font-size:13px}
.d-svg .tx-b{font-weight:700}
.d-svg .tx-s{font-size:11.5px;fill:var(--ink-2)}
.d-svg .tx-s.bad,.d-svg .bad{fill:var(--bad)}
.d-svg .bx{fill:var(--card);stroke:var(--ink-3);stroke-width:1.3}
.d-svg .bx.acc{stroke:var(--track);stroke-width:2.4;fill:color-mix(in srgb,var(--track) 8%,var(--card))}
.d-svg .ln{stroke:var(--ink-3);stroke-width:1.5;fill:none}
.d-svg .ln.acc{stroke:var(--track);stroke-width:2.6}
.d-svg .ln.bad{stroke:var(--bad);stroke-dasharray:5 4}
.d-svg .ln.hot{stroke:var(--bad);stroke-width:5;stroke-linecap:round}
.d-svg .mk{fill:var(--ink-3)} .d-svg .mk.acc{fill:var(--track)} .d-svg .mk.bad{fill:var(--bad)}
.d-svg .c1{fill:var(--lv1);fill-opacity:.14;stroke:var(--lv1);stroke-width:1.5}
.d-svg .c2{fill:var(--lv2);fill-opacity:.14;stroke:var(--lv2);stroke-width:1.5}
.d-svg .c3{fill:var(--track);fill-opacity:.14;stroke:var(--track);stroke-width:1.5}
.d-svg .risk{fill:var(--bad)} .d-svg .tx-risk{fill:#fff;font-size:11px;font-weight:800}
.d-svg .dot2{fill:var(--card);stroke:var(--track);stroke-width:2.5}
.d-flow{display:flex;align-items:stretch;flex-wrap:wrap;gap:6px;justify-content:center}
.d-step{flex:1 1 auto;min-width:80px;max-width:180px;border:1.5px solid var(--line);border-radius:8px;padding:8px 10px;text-align:center;background:var(--paper);display:flex;flex-direction:column;justify-content:center}
.d-step b{font-size:.88rem}
.d-step span{font-size:.76rem;color:var(--ink-2);line-height:1.3;margin-top:2px}
.d-step.t-g{border-color:var(--g);background:var(--g-bg)} .d-step.t-a{border-color:var(--a);background:var(--a-bg)} .d-step.t-r{border-color:var(--r);background:var(--r-bg)}
.d-arrow{align-self:center;color:var(--ink-3);font-weight:700}
.d-arrow::before{content:"→"}
.d-loop{flex-basis:100%;text-align:center;font-size:.8rem;color:var(--track);font-weight:600}
@media (max-width:560px){.d-flow{gap:4px}.d-step{flex:0 1 auto;min-width:0;padding:6px 8px}.d-step b{font-size:.8rem}.d-step span{font-size:.7rem}.ve .pt{font-size:.66rem;padding:2px 6px}}
.d-2x2{display:grid;grid-template-columns:auto 1fr;grid-template-rows:1fr auto;gap:6px;max-width:520px;margin:0 auto;width:100%}
.d-2x2 .ax-y,.d-risk .ax-y,.d-ve .ax-y{writing-mode:vertical-rl;transform:rotate(180deg);font-size:.78rem;color:var(--ink-2);text-align:center;font-weight:600}
.d-2x2 .ax-x,.d-risk .ax-x,.d-ve .ax-x{grid-column:2;text-align:center;font-size:.78rem;color:var(--ink-2);font-weight:600}
.q-wrap{display:grid;grid-template-columns:1fr 1fr;gap:6px}
.q-wrap .q{border:1.5px solid var(--line);border-radius:8px;padding:12px;min-height:84px;display:flex;flex-direction:column;gap:4px;background:var(--paper)}
.q-wrap .q b{font-size:.9rem} .q-wrap .q span{font-size:.8rem;color:var(--ink-2)}
.q-wrap .q.hot{border-color:var(--track);background:color-mix(in srgb,var(--track) 9%,var(--card))}
.q-wrap .q.cool{border-style:dashed}
.d-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:8px}
.d-card{border:1.5px solid var(--line);border-radius:8px;padding:10px 12px;background:var(--paper);display:flex;flex-direction:column;gap:3px}
.d-card b{font-size:.9rem} .d-card span{font-size:.8rem;color:var(--ink-2);line-height:1.35}
.d-card.acc{border-color:var(--track);background:color-mix(in srgb,var(--track) 9%,var(--card))}
.d-card.strike{border-style:dashed;opacity:.75} .d-card.strike span{text-decoration:line-through}
.d-tree{display:flex;flex-direction:column;align-items:center;gap:0;max-width:560px;margin:0 auto;width:100%}
.d-tree>.d-card.acc{max-width:340px;text-align:center}
.d-tree .kids{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;width:100%;position:relative;padding-top:22px;margin-bottom:12px}
.d-tree .kids::before{content:"";position:absolute;top:0;left:50%;height:11px;border-left:1.5px solid var(--ink-3)}
.d-tree .kids::after{content:"";position:absolute;top:11px;left:16.6%;right:16.6%;border-top:1.5px solid var(--ink-3)}
.d-tree .kids .d-card{position:relative}
.d-tree .kids .d-card::before{content:"";position:absolute;top:-11px;left:50%;height:11px;border-left:1.5px solid var(--ink-3)}
.d-tree>.d-card.strike{max-width:340px;text-align:center}
.d-scope{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.d-scope>div{border-radius:8px;padding:12px 14px;border:1.5px solid var(--lv1);background:var(--lv1-bg)}
.d-scope>div.out{border:1.5px dashed var(--ink-3);background:var(--paper)}
.d-scope ul{margin:6px 0;padding-left:1.1em;font-size:.88rem}
.d-scope .small{color:var(--ink-2)}
.d-stack{display:flex;border-radius:8px;overflow:hidden;min-height:58px}
.d-stack .sg{display:flex;flex-direction:column;justify-content:center;align-items:center;padding:6px 4px;min-width:0;text-align:center}
.d-stack .sg b{font-size:.92rem} .d-stack .sg span{font-size:.74rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:100%}
.d-stack .s1{background:var(--track);color:#fff} .d-stack .s2{background:color-mix(in srgb,var(--track) 55%,var(--card));color:#fff} .d-stack .s3{background:color-mix(in srgb,var(--track) 25%,var(--card));color:var(--ink)} .d-stack .s4{background:var(--soft);color:var(--ink-2)}
.d-risk{display:grid;grid-template-columns:auto 1fr;gap:6px;max-width:360px;margin:0 auto;width:100%}
.rgrid{display:grid;grid-template-columns:repeat(5,1fr);gap:3px}
.rc{aspect-ratio:1;border-radius:4px;display:grid;place-items:center;font-size:.72rem}
.rc.lo{background:var(--g-bg)} .rc.md{background:var(--a-bg)} .rc.hi{background:var(--r-bg)}
.rc b{background:var(--ink);color:var(--paper);padding:2px 5px;border-radius:4px;font-size:.7rem}
.d-bars{display:flex;flex-direction:column;gap:8px}
.d-bars .br{display:grid;grid-template-columns:minmax(110px,190px) 1fr;gap:10px;align-items:center}
.d-bars .bl{font-size:.84rem;color:var(--ink-2)}
.d-bars .bt{display:flex;height:26px;border-radius:6px;overflow:hidden;background:var(--soft)}
.d-bars .bt span{display:flex;align-items:center;justify-content:center;font-size:.74rem;font-weight:700;transition:width .5s}
.d-bars .new,.d-legend i.new{background:var(--track);color:#fff}
.d-bars .old,.d-legend i.old{background:color-mix(in srgb,var(--ink-3) 35%,var(--card));color:var(--ink)}
.d-legend{display:flex;gap:16px;font-size:.8rem;color:var(--ink-2);justify-content:flex-end}
.d-legend i{display:inline-block;width:12px;height:12px;border-radius:3px;margin-right:6px;vertical-align:-1px}
@media (max-width:560px){.d-bars .br{grid-template-columns:1fr}.d-scope{grid-template-columns:1fr}}
.d-ve{display:grid;grid-template-columns:auto 1fr;gap:6px;max-width:480px;margin:0 auto;width:100%}
.ve{position:relative;display:grid;grid-template-columns:1fr 1fr;gap:4px;aspect-ratio:1.5}
.ve .q{border-radius:6px;padding:8px;font-size:.8rem;color:var(--ink-2)}
.ve .q:nth-child(1){background:var(--g-bg)} .ve .q:nth-child(2){background:color-mix(in srgb,var(--track) 10%,var(--card))} .ve .q:nth-child(3){background:var(--soft)} .ve .q:nth-child(4){background:var(--r-bg)}
.ve .pt{position:absolute;transform:translate(-50%,-50%);background:var(--ink);color:var(--paper);font-size:.72rem;font-weight:600;padding:3px 8px;border-radius:999px;white-space:nowrap}

.eyebrow{font-size:.75rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--track);margin:0 0 6px;display:block}
.big-lede{font-size:1.08rem;max-width:66ch;color:var(--ink-2)}
.d-svg .big{font-size:18px}
.hero{display:flex;align-items:center;gap:18px;width:100%;text-align:left;background:var(--card);border:1.5px solid color-mix(in srgb,var(--track) 45%,var(--line));border-radius:12px;padding:14px 18px;margin-bottom:12px;cursor:pointer}
.hero:hover{border-color:var(--track)}
.hero>span:nth-child(2){flex:1;display:flex;flex-direction:column;gap:2px}
.hero b{font-size:1.05rem}
.hero .go{font-size:1.6rem;color:var(--track);font-weight:700}
.hero .hl{stroke:var(--track);stroke-width:2}
.hero .hb{fill:var(--soft);stroke:var(--ink-3);stroke-width:1.2}
.hero .hc{fill:var(--track)}
@media (max-width:560px){.hero svg{width:84px;height:50px}}
.d-life{display:grid;grid-template-columns:repeat(6,1fr);gap:22px}
.lc{position:relative;background:var(--paper);border:1.5px solid var(--line);border-radius:10px;padding:12px 12px 14px;display:flex;flex-direction:column;gap:4px}
.lc:not(:last-child)::after{content:"→";position:absolute;right:-18px;top:50%;transform:translateY(-50%);color:var(--track);font-weight:800}
.lc .n{width:24px;height:24px;border-radius:50%;background:var(--track);color:#fff;font-size:.78rem;font-weight:800;display:grid;place-items:center}
.lc b{font-size:.95rem}
.lc>span:last-child{font-size:.8rem;color:var(--ink-2);line-height:1.4}
.lc:nth-child(2),.lc:nth-child(3){border-color:var(--track)}
@media (max-width:900px){.d-life{grid-template-columns:1fr;gap:18px}.lc{flex-direction:row;flex-wrap:wrap;align-items:center;column-gap:10px}.lc>span:last-child{flex-basis:100%}.lc:not(:last-child)::after{content:"↓";right:auto;left:50%;top:auto;bottom:-19px;transform:translateX(-50%)}}
.resp{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.rcard{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;display:flex;flex-direction:column;gap:6px}
.rcard svg{color:var(--track)}
.rcard b{font-size:1rem}
.rcard>span{font-size:.88rem;color:var(--ink-2);flex:1}
.linkish{background:none;border:0;padding:0;color:var(--track);font-weight:700;cursor:pointer;text-align:left;font-size:.88rem}
td.hl{background:color-mix(in srgb,var(--track) 8%,transparent);font-weight:600}
.dayline{list-style:none;margin:0;padding:0;position:relative}
.dayline::before{content:"";position:absolute;left:61px;top:8px;bottom:8px;border-left:2px solid var(--line)}
.dayline li{display:grid;grid-template-columns:46px 1fr;gap:30px;padding:7px 0;position:relative}
.dayline li::before{content:"";position:absolute;left:56px;top:14px;width:12px;height:12px;border-radius:50%;background:var(--card);border:2.5px solid var(--track)}
.dayline .tm{font-weight:700;font-variant-numeric:tabular-nums;color:var(--ink-2);font-size:.9rem;padding-top:1px}
.ladder{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;align-items:end}
.rung{display:flex;flex-direction:column;gap:3px}
.rung .bar{height:calc(var(--h) * 26px);border-radius:6px 6px 0 0;background:color-mix(in srgb,var(--track) calc(var(--h) * 22%),var(--soft));margin-bottom:6px}
.rung b{font-size:.92rem} .rung span{font-size:.8rem;color:var(--ink-2)}
@media (max-width:560px){.ladder{grid-template-columns:repeat(2,1fr)}}
.d-step.stage-basic{border-color:var(--lv1);background:var(--lv1-bg)} .d-step.stage-medium{border-color:var(--lv2);background:var(--lv2-bg)} .d-step.stage-hard{border-color:var(--lv3);background:var(--lv3-bg)}

main{min-width:0}

.hub-list{display:none;list-style:none;margin:0;padding:0}
.hub-list li{display:flex;flex-direction:column;padding:8px 0;border-top:1px solid var(--line)}
.hub-list li b{font-size:.9rem} .hub-list li span{font-size:.84rem;color:var(--ink-2)}
@media (max-width:560px){.hub-list{display:block}.d-flow.stages{flex-direction:column;align-items:stretch}.d-flow.stages .d-step{max-width:none}.d-flow.stages .d-arrow::before{content:"↓"}}

.hero2{border-color:color-mix(in srgb,var(--lv1) 45%,var(--line))}
.hero2:hover{border-color:var(--lv1)} .hero2 .eyebrow,.hero2 .go{color:var(--lv1)}
.hico{width:56px;height:56px;border-radius:12px;background:var(--lv1-bg);color:var(--lv1);display:grid;place-items:center;flex:none}
.chip.phase{background:var(--ink);color:var(--paper)} .chip.fmt{background:var(--soft);color:var(--ink-2)} .chip.techchip{background:var(--lv1-bg);color:var(--lv1)}
.tplstep{cursor:pointer;font:inherit;color:inherit} .tplstep.on{border-color:var(--track);background:color-mix(in srgb,var(--track) 10%,var(--card))}
pre.tpl.big{font-size:.84rem;line-height:1.55;max-height:none;background:var(--card);border:1px solid var(--line);padding:16px}
textarea.mono{font-family:ui-monospace,"SF Mono",Menlo,Consolas,monospace;font-size:.84rem}
table.csvt th,table.csvt td{white-space:nowrap;font-size:.82rem}
.asklist{margin:0;padding-left:1.3em} .asklist li{padding:4px 0;font-weight:500}
.gloss{margin:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:8px}
.gloss>div{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:10px 12px}
.gloss dt{font-weight:700} .gloss dd{margin:2px 0 0;font-size:.88rem;color:var(--ink-2)}
.analogy{display:flex;gap:14px;align-items:flex-start;background:var(--a-bg);border-radius:12px;padding:14px 16px;margin-top:16px}
.analogy svg{color:var(--a);flex:none;margin-top:2px}
.analogy p{margin:4px 0 0}
.d-cloud{display:grid;grid-template-columns:minmax(90px,1.2fr) repeat(4,1fr);gap:3px;font-size:.8rem}
.d-cloud .ch{font-weight:700;text-align:center;padding:4px 2px}
.d-cloud .rh{font-weight:600;color:var(--ink-2);padding:8px 4px;display:flex;align-items:center}
.d-cloud .cell{text-align:center;padding:8px 2px;border-radius:4px;font-weight:600}
.d-cloud .you{background:color-mix(in srgb,var(--ink-3) 25%,var(--card));color:var(--ink)}
.d-cloud .them{background:var(--track);color:#fff}
@media (max-width:560px){.d-cloud{font-size:.68rem}}

.recs{border-color:color-mix(in srgb,var(--track) 40%,var(--line))}
.recgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:8px}
.rec{text-align:left;background:var(--paper);border:1.5px solid var(--line);border-radius:10px;padding:12px;cursor:pointer;display:flex;flex-direction:column;gap:4px;font:inherit;color:inherit}
.rec:hover{border-color:var(--track)} .rec b{font-size:.95rem} .rec span{font-size:.82rem;color:var(--ink-2)}
.search{display:flex;align-items:center;gap:8px;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:0 12px;margin-bottom:16px;color:var(--ink-3)}
.search input{border:0;background:none;padding:12px 0;flex:1;width:auto}
.search input:focus-visible{outline:none} .search:focus-within{border-color:var(--focus);box-shadow:0 0 0 2px color-mix(in srgb,var(--focus) 25%,transparent)}
.seg{display:inline-flex;background:var(--soft);border-radius:10px;padding:3px;gap:3px}
.segb{border:0;background:none;padding:7px 14px;border-radius:8px;font-weight:600;font-size:.88rem;cursor:pointer;color:var(--ink-2)}
.segb[aria-pressed="true"]{background:var(--card);color:var(--ink);box-shadow:0 1px 2px rgba(0,0,0,.12)}
.exnote{background:var(--a-bg);padding:8px 12px;border-radius:8px;margin:10px 0 0}
.chip.new{background:var(--hot);color:#fff}
.story{display:flex;gap:12px;align-items:flex-start;background:var(--lv2-bg);border-radius:12px;padding:14px 16px}
.story svg{color:var(--lv2);flex:none;margin-top:2px} .story p{margin:0}
.deeper summary{font-size:1.05rem}
.badge-panel{display:flex;align-items:center;gap:16px;background:var(--card);border:1.5px solid var(--lv1);border-radius:12px;padding:14px 18px;margin-top:12px;flex-wrap:wrap}
.badge-panel>div{flex:1;min-width:200px}
.badge-panel.locked{border-color:var(--line)} .badge-panel.locked svg{filter:grayscale(1);opacity:.5}
.bdg-r{fill:var(--lv2)} .bdg-c{fill:var(--lv1)} .bdg-i{fill:none;stroke:#fff;stroke-width:2;stroke-dasharray:3 3} .bdg-k{fill:none;stroke:#fff;stroke-width:4;stroke-linecap:round;stroke-linejoin:round}
.result{display:flex;align-items:center;gap:20px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px;margin-top:6px;flex-wrap:wrap}
.result>div{flex:1;min-width:220px} .result:not(.pass) svg{filter:grayscale(1);opacity:.5} .result.pass{border-color:var(--lv1);background:var(--lv1-bg)}
.quiz-opt.sel{border-color:var(--track);background:color-mix(in srgb,var(--track) 10%,var(--card));font-weight:600}
.badwrd{color:var(--r);font-weight:700} .goodwrd{color:var(--g);font-weight:700}
.d-pyr{display:flex;flex-direction:column;align-items:center;gap:4px}
.d-pyr .lvl{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:8px;border-radius:6px;color:#fff;text-align:center}
.d-pyr .lvl span{font-size:.76rem;opacity:.9}
.d-pyr .l3{width:40%;background:var(--lv3)} .d-pyr .l2{width:65%;background:var(--lv2)} .d-pyr .l1{width:90%;background:var(--lv1)}
@media (max-width:560px){.d-pyr .l3{width:60%}.d-pyr .l2{width:80%}.d-pyr .l1{width:100%}}

.md{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:18px 22px;line-height:1.6}
.md .md-h1{font-size:1.25rem;margin:0 0 10px} .md .md-h2{font-size:1.02rem;margin:20px 0 8px;color:var(--track)} .md .md-h3{font-size:.95rem;margin:14px 0 6px}
.md p{margin:8px 0} .md ul,.md ol{margin:6px 0;padding-left:1.3em} .md table{font-size:.86rem;margin:6px 0 10px}
.md p{white-space:pre-wrap}

.ink{color:var(--ink)} .tiny{font-size:.72rem;display:block}
.decks{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:10px}
.deck{text-align:left;background:var(--card);border:1.5px solid var(--line);border-radius:12px;padding:12px 14px;cursor:pointer;display:flex;flex-direction:column;gap:3px;font:inherit;color:inherit}
.deck:hover{border-color:var(--ink-3)} .deck.on{border-color:var(--track);box-shadow:0 0 0 2px color-mix(in srgb,var(--track) 20%,transparent)}
.deck b{font-size:.95rem} .deck>span:nth-child(2){font-size:.78rem;color:var(--ink-2);flex:1}
.deck .dm{display:flex;justify-content:space-between;font-size:.76rem;color:var(--ink-3);margin-top:6px} .deck .dm .due{color:var(--hot);font-weight:700}
.mbar{height:4px;background:var(--soft);border-radius:2px;overflow:hidden;margin-top:4px} .mbar i{display:block;height:100%;background:var(--lv1)}
.modes{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.mode{text-align:left;background:var(--paper);border:1.5px solid var(--line);border-radius:10px;padding:10px 12px;cursor:pointer;display:flex;flex-direction:column;gap:2px;font:inherit;color:inherit}
.mode b{font-size:.9rem} .mode span{font-size:.76rem;color:var(--ink-2)} .mode.on{border-color:var(--track);background:color-mix(in srgb,var(--track) 9%,var(--card))}
@media (max-width:560px){.modes{grid-template-columns:1fr}}
.boxcol .tiny{margin-top:2px}
.flash3d{margin:10px auto 0;max-width:640px;perspective:1400px;cursor:pointer;touch-action:pan-y}
.flash3d.mc{cursor:default}
.flash3d>.face,.flash3d .inner{min-height:230px}
.flash3d>.face{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:24px;display:flex;flex-direction:column;justify-content:center}
.flash3d .inner{position:relative;transition:transform .45s cubic-bezier(.2,.7,.2,1);transform-style:preserve-3d}
.flash3d.flipped .inner{transform:rotateY(180deg)}
.flash3d .inner .face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:24px;display:flex;flex-direction:column;justify-content:center;gap:6px;box-shadow:0 1px 0 var(--line),0 10px 0 -5px var(--soft),0 11px 0 -5px var(--line);overflow:auto}
.flash3d .inner .face.b{transform:rotateY(180deg);border-color:color-mix(in srgb,var(--track) 40%,var(--line))}
.flash3d .tap{margin-top:auto;text-align:center}
.flash3d .fq{font-size:1.35rem;font-weight:700;margin:4px 0 0;line-height:1.35}
.flash3d .fa{font-size:1.05rem;margin:4px 0 0;line-height:1.55}
.flash3d.swr .face.b{border-color:var(--g);background:var(--g-bg)} .flash3d.swl .face.b{border-color:var(--r);background:var(--r-bg)}
@media (prefers-reduced-motion:reduce){.flash3d .inner{transition:none}}
.grades{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin:18px auto 0;max-width:640px}
.gbtn{border:1.5px solid var(--line);background:var(--card);border-radius:10px;padding:10px 4px;cursor:pointer;display:flex;flex-direction:column;align-items:center;gap:2px;font:inherit;color:inherit}
.gbtn b{font-size:.92rem} .gbtn span{font-size:.74rem;color:var(--ink-3)}
.gbtn.again{border-color:var(--r);color:var(--r)} .gbtn.hard{border-color:var(--a)} .gbtn.good{border-color:var(--track);background:var(--track);color:#fff} .gbtn.good span{color:#fff;opacity:.85} .gbtn.easy{border-color:var(--g)}
.compare{max-width:640px;margin:14px auto 0;background:var(--soft);border-radius:10px;padding:12px 14px;display:flex;flex-direction:column;gap:8px}
.compare p{margin:2px 0 0}
.mcopts{max-width:640px;margin:14px auto 10px}
.quiz-opt:disabled{cursor:default;color:inherit;opacity:1}
.star{border:0;background:none;font-size:1.25rem;line-height:1;color:var(--line);cursor:pointer;padding:2px 4px} .star.on{color:var(--a)}
.chip.deckchip{background:var(--soft);color:var(--ink-2)}
.bcard{display:flex;gap:12px;justify-content:space-between;align-items:flex-start;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:12px 14px;margin-bottom:8px}
.bcard>div:first-child{display:flex;flex-direction:column;gap:2px;min-width:0} .bcard>div:first-child>span:last-child{font-size:.88rem;color:var(--ink-2)}
.bside{display:flex;align-items:center;gap:4px;flex-wrap:wrap;justify-content:flex-end}
.boxpill{font-size:.7rem;font-weight:700;padding:2px 8px;border-radius:999px;background:var(--soft);color:var(--ink-2);white-space:nowrap}
.boxpill.b5{background:var(--lv1-bg);color:var(--lv1)} .boxpill.b3,.boxpill.b4{background:color-mix(in srgb,var(--track) 12%,var(--card));color:var(--track)}

.ainote{display:inline-flex;align-items:center;gap:6px;font-size:.88rem;color:var(--ink-2);background:var(--soft);padding:7px 12px;border-radius:8px}
.ainote svg{color:var(--lv2);flex:none}
.aipanel{border-left:4px solid var(--line)} .aipanel.live{border-left-color:var(--lv1)}
.aipanel .eyebrow{display:inline-flex;align-items:center;gap:4px}
.switch{width:46px;height:26px;border-radius:999px;border:0;background:var(--line);position:relative;cursor:pointer;flex:none;transition:background .15s}
.switch i{position:absolute;top:3px;left:3px;width:20px;height:20px;border-radius:50%;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,.25);transition:left .15s}
.switch.on{background:var(--lv1)} .switch.on i{left:23px}
.switch.big{width:64px;height:34px} .switch.big i{width:28px;height:28px} .switch.big.on i{left:33px}


/* ---------- standalone sign-in ---------- */
#auth[hidden]{display:none}
.auth-wrap{position:fixed;inset:0;z-index:100;display:grid;place-items:center;padding:20px;background:var(--paper)}
.auth-card{width:100%;max-width:400px;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:28px}
.auth-card h1{font-size:1.6rem;margin:8px 0 6px}
.auth-card input{margin-bottom:4px}
.auth-brand{display:flex;align-items:center;gap:8px;font-weight:800;color:var(--track)}
.auth-brand .dot{width:12px;height:12px;border-radius:50%;background:var(--track)}
.auth-btn{width:100%;justify-content:center;margin-top:14px;padding:11px}
.auth-msg{color:var(--bad);font-size:.88rem;margin:8px 0 0}
.auth-or{display:flex;align-items:center;gap:10px;color:var(--ink-3);font-size:.8rem;margin-top:14px}
.auth-or::before,.auth-or::after{content:"";flex:1;border-top:1px solid var(--line)}
code{background:var(--soft);padding:1px 5px;border-radius:4px}
input[type=email]{width:100%;border:1px solid var(--line);background:var(--card);border-radius:8px;padding:9px 11px}

.path button.node:first-of-type .lbl{left:-8px}
.lvl-head h2{flex-wrap:wrap;row-gap:4px}