/* Layout idea: a reading app with one chapter per page — sticky top bar (search, theme, XP), chapter rail on the left, a calm 68ch column, and every chapter opening on a generative banner and closing on a hands-on tool + quiz. */
:root{
  --bg:#f2f3f7; --surface:#ffffff; --ink:#141c33; --muted:#586179; --line:#dce0ea;
  --accent:#d93a28;--accent-ink:#b8321f;--on-accent:#fff;--good-ink:#146652;--warn-ink:#855700; --accent-soft:#fde9e5; --blue:#2c56e0; --blue-soft:#e6ecfd;
  --good:#1a7d66; --good-soft:#dff3ed; --warn:#a46c00; --warn-soft:#fbefd6;
  --font-display:"Unbounded","Noto Sans","Arial Black",system-ui,sans-serif;
  --font-body:"Golos Text","Noto Sans","Segoe UI",system-ui,-apple-system,sans-serif;
  --radius:12px; --rail:270px;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0d1220; --surface:#151c30; --ink:#e8ebf3; --muted:#9aa3b8; --line:#28314b;
    --accent:#ff6a55;--accent-ink:#ff6a55;--on-accent:#0d1220;--good-ink:#43c39d;--warn-ink:#f0b429; --accent-soft:#3a2024; --blue:#7c9bff; --blue-soft:#1c2647;
    --good:#43c39d; --good-soft:#14302a; --warn:#f0b429; --warn-soft:#342a13;
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0d1220; --surface:#151c30; --ink:#e8ebf3; --muted:#9aa3b8; --line:#28314b;
  --accent:#ff6a55;--accent-ink:#ff6a55;--on-accent:#0d1220;--good-ink:#43c39d;--warn-ink:#f0b429; --accent-soft:#3a2024; --blue:#7c9bff; --blue-soft:#1c2647;
  --good:#43c39d; --good-soft:#14302a; --warn:#f0b429; --warn-soft:#342a13;
  color-scheme:dark;
}
*{box-sizing:border-box}
html{scroll-padding-top:72px}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font-body);font-size:17px;line-height:1.62}
a{color:var(--accent-ink)}
h1,h2,h3{text-wrap:balance;line-height:1.2}
h1,h2{font-family:var(--font-display);font-weight:700;letter-spacing:-.01em}
h3{font-size:1.12rem;margin:1.8em 0 .5em}
p{margin:0 0 1em}
:focus-visible{outline:3px solid var(--blue);outline-offset:2px;border-radius:4px}
.num{font-variant-numeric:tabular-nums}
.muted{color:var(--muted)}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
button{font:inherit;cursor:pointer;color:inherit}
@media (prefers-reduced-motion: reduce){*{transition:none!important;animation:none!important}}

/* top bar */
.topbar{position:sticky;top:0;z-index:40;background:var(--surface);border-bottom:1px solid var(--line);display:flex;align-items:center;gap:12px;padding:9px 18px}
.brand{font-family:var(--font-display);font-weight:700;font-size:15px;white-space:nowrap;text-decoration:none;color:var(--ink)}
.brand b{color:var(--accent)}
.progress{flex:1;display:flex;align-items:center;gap:10px;min-width:60px}
.bar{flex:1;height:8px;background:var(--line);border-radius:99px;overflow:hidden}
.bar>span{display:block;height:100%;width:0;background:var(--accent);border-radius:99px;transition:width .4s}
.xp{display:flex;align-items:center;gap:8px;font-size:13px;font-weight:600;white-space:nowrap;padding:5px 11px;border-radius:99px;background:var(--blue-soft);color:var(--blue)}
.lang{display:flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:99px;padding:0 4px 0 10px;height:38px;background:var(--surface)}
.lang svg{width:16px;height:16px;flex:none;color:var(--muted)}
.lang select{border:0;background:transparent;padding:6px 4px;font-size:14px;font-weight:600;width:auto;color:var(--ink);cursor:pointer}
.lang select option{background:var(--bg);color:var(--ink);font-weight:500}
.lang select option:checked{background:var(--accent);color:var(--on-accent)}
.iconbtn{width:38px;height:38px;border-radius:50%;border:1px solid var(--line);background:var(--surface);display:grid;place-items:center;flex:none}
.iconbtn:hover{border-color:var(--ink)}
.iconbtn svg{width:18px;height:18px}
.menu-btn{display:none}
.btn{border:1px solid var(--line);background:var(--surface);color:var(--ink);padding:9px 16px;border-radius:999px;font-weight:600;font-size:15px;text-decoration:none;display:inline-flex;align-items:center;gap:8px}
.btn:hover{border-color:var(--ink)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent)}
.btn.primary:hover{filter:brightness(1.07)}
.btn.done{background:var(--good-soft);border-color:var(--good);color:var(--good)}
.btn.small{padding:6px 12px;font-size:14px}

/* search */
.search-panel{position:fixed;inset:0;z-index:60;background:rgba(10,14,28,.55);display:none;align-items:flex-start;justify-content:center;padding:70px 16px}
.search-panel.open{display:flex}
.search-box{width:min(680px,100%);background:var(--surface);border-radius:16px;border:1px solid var(--line);overflow:hidden;max-height:calc(100vh - 120px);display:flex;flex-direction:column}
.search-box input{border:0;border-bottom:1px solid var(--line);border-radius:0;font-size:18px;padding:16px 18px;background:var(--surface)}
.search-results{overflow:auto;padding:8px}
.search-results a{display:block;padding:10px 12px;border-radius:8px;text-decoration:none;color:var(--ink)}
.search-results a:hover,.search-results a:focus{background:var(--bg)}
.search-results small{display:block;color:var(--muted);font-size:13px}
.search-results mark{background:var(--warn-soft);color:var(--ink);border-radius:3px;padding:0 2px}
.search-empty{padding:16px;color:var(--muted)}

/* shell */
.shell{display:grid;grid-template-columns:var(--rail) minmax(0,1fr);gap:40px;max-width:1240px;margin:0 auto;padding:0 20px}
.rail{position:sticky;top:57px;align-self:start;max-height:calc(100vh - 57px);overflow:auto;padding:22px 0 40px}
.rail h4{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:16px 0 6px}
.rail ol{list-style:none;margin:0;padding:0;display:grid;gap:2px}
.rail a{display:flex;gap:10px;align-items:flex-start;padding:6px 10px;border-radius:8px;color:var(--ink);text-decoration:none;font-size:15px;line-height:1.35}
.rail a:hover{background:var(--surface)}
.rail a.active{background:var(--surface);box-shadow:inset 3px 0 0 var(--accent);font-weight:600}
.rail .n{flex:none;width:22px;height:22px;border-radius:50%;border:1.5px solid var(--line);font-size:11px;display:grid;place-items:center;font-weight:700;color:var(--muted)}
.rail a.read .n{background:var(--good);border-color:var(--good);color:#fff}
.rail a.dim{opacity:1}.rail a.dim .t{color:var(--muted)}.rail a.dim .n{opacity:.55}
.rail a.rec .n{border-color:var(--accent);color:var(--accent-ink)}
.rail a.read.rec .n{color:#fff}
.rail .t{flex:1}
.rail .rt{font-size:12px;color:var(--muted);white-space:nowrap}

main{min-width:0;padding:28px 0 90px}
.col{max-width:68ch}
.page{animation:pagein .35s ease-out}
@keyframes pagein{from{opacity:.4;transform:translateY(6px)}to{opacity:1;transform:none}}

/* home hero */
.hero{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);gap:36px;align-items:center;padding:12px 0 8px}
.eyebrow{font-size:13px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent-ink);font-weight:700}
.hero h1{font-size:clamp(2.1rem,5vw,3.5rem);margin:.15em 0 .3em}
.hero h1 em{font-style:normal;color:var(--accent)}
.hero .lead{font-size:1.18rem;color:var(--muted);max-width:52ch}
.hero-cta{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px}
.cover-wrap{perspective:1200px;display:grid;place-items:center}
.cover{width:min(300px,80vw);aspect-ratio:2/3;border-radius:6px 14px 14px 6px;position:relative;overflow:hidden;background:#141c33;color:#fff;transform:rotateY(-14deg) rotateX(4deg);box-shadow:24px 30px 60px rgba(13,18,40,.35),inset 8px 0 0 rgba(255,255,255,.08);transition:transform .5s}
.cover:hover{transform:rotateY(-4deg) rotateX(1deg)}
.cover canvas{position:absolute;inset:0;width:100%;height:100%}
.cover-text{position:absolute;inset:0;padding:26px 22px;display:flex;flex-direction:column;justify-content:space-between}
.cover-text .k{font-size:11px;letter-spacing:.14em;text-transform:uppercase;opacity:.8}
.cover-text h2{font-family:var(--font-display);font-size:2.15rem;line-height:1.02;margin:0;color:#fff}
.cover-text h2 b{color:#ff7a66}
.cover-text p{font-size:13px;margin:0;opacity:.9;line-height:1.4}
.ticker{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:34px 0 0}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px}
.stat b{display:block;font-family:var(--font-display);font-size:1.6rem;line-height:1.1}
.stat span{font-size:14px;color:var(--muted)}
.section-title{display:flex;justify-content:space-between;align-items:baseline;gap:12px;margin:52px 0 14px;flex-wrap:wrap}
.section-title h2{font-size:1.45rem;margin:0}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.card{display:grid;grid-template-rows:96px auto;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;text-decoration:none;color:var(--ink);transition:transform .2s,border-color .2s}
.card:hover{transform:translateY(-3px);border-color:var(--ink)}
.card canvas{width:100%;height:96px;display:block}
.card div{padding:12px 14px 14px}
.card b{display:block;font-size:15px;line-height:1.3}
.card small{color:var(--muted);font-size:13px}
.card.read{border-color:var(--good)}
.card.rec{box-shadow:0 0 0 2px var(--accent)}

/* chapter */
.banner{position:relative;height:190px;border-radius:16px;overflow:hidden;background:#141c33;margin-bottom:24px}
.banner canvas{position:absolute;inset:0;width:100%;height:100%}
.banner .bn{position:absolute;left:22px;bottom:14px;font-family:var(--font-display);font-size:4.6rem;line-height:1;color:#fff;opacity:.95}
.banner .bp{position:absolute;right:20px;top:16px;font-size:12px;letter-spacing:.1em;text-transform:uppercase;color:#fff;background:rgba(0,0,0,.28);padding:4px 10px;border-radius:99px}
.chapter h1{font-size:clamp(1.6rem,3.6vw,2.3rem);margin:0 0 .3em}
.meta{display:flex;gap:14px;flex-wrap:wrap;color:var(--muted);font-size:14px;margin-bottom:14px}
.hook{font-size:1.25rem;line-height:1.45;font-weight:500;border-left:4px solid var(--accent);padding:4px 0 4px 16px;margin:18px 0 22px}
.tldr{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin:18px 0 22px}
.tldr b{display:block;font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent-ink);margin-bottom:4px}
.tldr ul{margin:0;padding-left:18px}
.note{background:var(--warn-soft);border-radius:10px;padding:12px 16px;font-size:15px;margin:16px 0}
.note b{color:var(--warn)}
.case{background:var(--blue-soft);border-radius:12px;padding:16px 18px;margin:22px 0;max-width:68ch}
.case .ct{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--blue);font-weight:700}
.case h4{margin:4px 0 8px;font-size:1.05rem}
.case .nums{display:flex;gap:10px;flex-wrap:wrap;margin:10px 0 6px}
.case .nums span{background:var(--surface);border-radius:8px;padding:6px 10px;font-size:14px}
.case .nums b{font-variant-numeric:tabular-nums}
.case small{color:var(--muted);font-size:13px}
.challenge{border:2px dashed var(--accent);border-radius:12px;padding:14px 18px;margin:26px 0;max-width:68ch}
.challenge b{color:var(--accent-ink)}
.src{font-size:14px;color:var(--muted)}
.chapter-foot{margin-top:28px;display:flex;gap:10px;flex-wrap:wrap;align-items:center;justify-content:space-between;max-width:68ch;border-top:1px solid var(--line);padding-top:18px}
.chapter-foot .navs{display:flex;gap:8px;flex-wrap:wrap}
.notes-box{max-width:68ch;margin-top:26px}
.notes-box textarea{min-height:90px}
.notes-actions{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:8px}

/* tables, lists */
.table-wrap{overflow-x:auto;margin:16px 0 20px;border:1px solid var(--line);border-radius:var(--radius);background:var(--surface);max-width:820px}
table{border-collapse:collapse;width:100%;font-size:15px}
th,td{padding:10px 14px;text-align:left;vertical-align:top;border-bottom:1px solid var(--line)}
th{font-size:13px;color:var(--muted);font-weight:600;background:var(--bg)}
tr:last-child td{border-bottom:0}
.pill{display:inline-block;font-size:12px;font-weight:700;padding:2px 9px;border-radius:99px;white-space:nowrap}
.pill.lo{background:var(--good-soft);color:var(--good-ink)}
.pill.mid{background:var(--warn-soft);color:var(--warn-ink)}
.pill.hi{background:var(--accent-soft);color:var(--accent-ink)}
.steps{counter-reset:s;list-style:none;padding:0;display:grid;gap:10px;margin:14px 0}
.steps li{counter-increment:s;display:grid;grid-template-columns:32px 1fr;gap:12px}
.steps li::before{content:counter(s);width:28px;height:28px;border-radius:50%;background:var(--ink);color:var(--bg);display:grid;place-items:center;font-weight:700;font-size:14px;margin-top:1px}

/* tools */
.tool{background:var(--surface);border:1.5px solid var(--ink);border-radius:16px;padding:20px;margin:26px 0;max-width:820px}
.tool-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap;margin-bottom:14px}
.tool-head strong{font-family:var(--font-display);font-size:15px}
.tool-head span{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent-ink);font-weight:700}
.grid2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.grid3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}
label{display:grid;gap:4px;font-size:14px;color:var(--muted);font-weight:500}
input[type="number"],input[type="text"],input[type="date"],input[type="search"],textarea,select{font:inherit;font-size:16px;color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:8px;padding:9px 11px;width:100%}
textarea{resize:vertical;min-height:70px}
input[type="range"]{width:100%;accent-color:var(--accent)}
.out{display:grid;gap:10px;margin-top:16px}
.out-row{display:grid;grid-template-columns:1fr auto;gap:12px;align-items:center;padding:12px 14px;border-radius:10px;background:var(--bg)}
.out-row b{font-size:1.25rem;font-variant-numeric:tabular-nums;text-align:right}
.out-row small{display:block;color:var(--muted);font-size:13px}
.out-row.best{background:var(--good-soft)}
.out-row.bad{background:var(--accent-soft)}
.meter{height:12px;border-radius:99px;background:var(--line);overflow:hidden;margin-top:8px}
.meter span{display:block;height:100%;transition:width .3s}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{border:1.5px solid var(--line);background:var(--bg);color:var(--ink);padding:7px 13px;border-radius:999px;font-size:15px}
.chip[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:var(--bg)}
.result-list{list-style:none;padding:0;margin:14px 0 0;display:grid;gap:8px}
.result-list li{padding:10px 14px;border-radius:8px;background:var(--bg);font-size:15px}
.result-list li b{display:block}
.gen-out{white-space:pre-wrap;background:var(--bg);border:1px dashed var(--line);border-radius:10px;padding:14px 16px;font-size:15px;margin-top:14px;min-height:60px}
.big-out{font-family:var(--font-display);font-size:1.25rem;line-height:1.35;margin:14px 0 6px}
.toast{font-size:14px;color:var(--good);margin-left:10px}
.row-actions{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:12px}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:99px;overflow:hidden}
.seg button{border:0;background:var(--surface);padding:6px 12px;font-size:14px;font-weight:600}
.seg button[aria-pressed="true"]{background:var(--ink);color:var(--bg)}

/* quiz */
.q{padding:14px 0;border-top:1px solid var(--line)}
.q:first-child{border-top:0;padding-top:0}
.q p{margin:0 0 8px;font-weight:600}
.opts{display:flex;flex-wrap:wrap;gap:8px}
.opt{border:1.5px solid var(--line);background:var(--bg);color:var(--ink);padding:7px 13px;border-radius:8px;font-size:15px;text-align:left}
.opt:hover:not(:disabled){border-color:var(--ink)}
.opt.right{background:var(--good-soft);border-color:var(--good);color:var(--good);font-weight:600}
.opt.wrong{background:var(--accent-soft);border-color:var(--accent);color:var(--accent-ink)}
.opt:disabled{cursor:default}
.why{font-size:14px;color:var(--muted);margin-top:8px;display:none}
.q.answered .why{display:block}
.score{font-weight:700;margin-top:12px}

/* plan */
.week{margin:18px 0}
.week h3{margin:0 0 8px;display:flex;justify-content:space-between;gap:10px}
.week h3 small{font-weight:500;color:var(--muted);font-size:14px}
.task{display:flex;gap:12px;align-items:flex-start;padding:9px 12px;border-radius:8px;background:var(--bg);margin:6px 0;cursor:pointer;color:var(--ink);font-size:15px;font-weight:400}
.task input{width:20px;height:20px;margin:2px 0 0;accent-color:var(--good);flex:none}
.task .d{margin-left:auto;font-size:13px;color:var(--muted);white-space:nowrap;padding-left:10px}
.task.today{box-shadow:inset 3px 0 0 var(--accent)}
.task.today .d{color:var(--accent-ink);font-weight:700}
.task.checked span:not(.d){color:var(--muted);text-decoration:line-through}
.ring{display:flex;align-items:center;gap:14px}
.verdict{margin-top:14px;padding:14px 16px;border-radius:10px;font-size:15px}
.verdict.must{background:var(--accent-soft)}
.verdict.ok{background:var(--good-soft)}

/* charts & diagrams */
.figure{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:18px;margin:22px 0;max-width:820px}
.figure figcaption{font-size:14px;color:var(--muted);margin-top:8px}
.figure svg{width:100%;height:auto;display:block}
.figure .ft{font-weight:700;font-size:15px;margin-bottom:6px}

/* prompts & glossary */
.toolbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:16px 0}
.toolbar input{max-width:320px}
.prompt-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px}
.prompt{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 16px;display:grid;gap:8px;align-content:start}
.prompt .pt{display:flex;justify-content:space-between;gap:8px;align-items:baseline}
.prompt .pt b{font-size:15px}
.prompt .tag{font-size:12px;color:var(--blue);font-weight:700;white-space:nowrap}
.prompt p{font-size:14px;margin:0;color:var(--ink);white-space:pre-wrap;background:var(--bg);border-radius:8px;padding:10px 12px}
.gloss{display:grid;gap:10px;max-width:820px}
.gloss div{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:12px 16px}
.gloss b{display:block}
.gloss span{font-size:15px;color:var(--muted)}
.saved{display:grid;gap:10px;max-width:820px}
.saved .item{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:12px 16px}
.saved blockquote{margin:0 0 6px;font-style:italic}
.level-card{display:flex;gap:18px;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:16px 18px;max-width:820px;flex-wrap:wrap}
.level-card .lv{font-family:var(--font-display);font-size:1.3rem}
.badges{display:flex;gap:8px;flex-wrap:wrap}
.badge{font-size:13px;padding:5px 10px;border-radius:99px;background:var(--bg);color:var(--muted);border:1px solid var(--line)}
.badge.on{background:var(--good-soft);color:var(--good);border-color:var(--good);font-weight:600}
.floating-save{position:absolute;z-index:50;display:none}
.floating-save.show{display:inline-flex}
.toast-global{position:fixed;left:50%;bottom:24px;transform:translateX(-50%) translateY(20px);background:var(--ink);color:var(--bg);padding:10px 18px;border-radius:99px;font-size:15px;font-weight:600;opacity:0;transition:all .3s;z-index:70;pointer-events:none}
.toast-global.show{opacity:1;transform:translateX(-50%)}
footer{margin-top:60px;color:var(--muted);font-size:14px;max-width:68ch}

@media (max-width: 980px){
  .shell{grid-template-columns:1fr;gap:0}
  .menu-btn{display:grid}
  .rail{display:none;position:fixed;top:57px;left:0;right:0;bottom:0;max-height:none;background:var(--bg);z-index:30;padding:16px 20px 40px}
  .rail.open{display:block}
  .hero{grid-template-columns:1fr}
  .cover-wrap{order:-1}
  .ticker{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width: 640px){
  body{font-size:16px}
  .grid2,.grid3{grid-template-columns:1fr}
  .progress{display:none}
  .xp{display:none}
  .brand{display:none}
  .banner{height:140px}
  .banner .bn{font-size:3.2rem}
}

.pw{text-align:center;max-width:620px;margin:60px auto}
.pw h1{font-family:Unbounded,system-ui,sans-serif;font-size:1.8rem;margin:12px 0}
.pw-tag{display:inline-block;font-size:12px;letter-spacing:.08em;text-transform:uppercase;font-weight:700;color:var(--good);border:1.5px solid var(--good);border-radius:99px;padding:3px 12px}
.pw-form{margin:34px auto 0;max-width:420px;text-align:left}
.pw-form label{font-size:14px;color:var(--muted)}
.pw-row{display:flex;gap:8px;margin-top:6px}
.pw-row input{flex:1}
.pw-err{display:block;color:var(--accent-ink);font-size:13px;min-height:18px;margin-top:6px}
/* community + updates */
.x-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin:36px 0 10px;max-width:880px}
.x-box{display:flex;gap:14px;align-items:flex-start;background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:18px 20px}
.x-box>svg{flex:none;color:var(--accent);margin-top:2px}
.x-box h3{margin:0 0 6px;font-size:1.05rem}
.x-box p{margin:0 0 12px;color:var(--muted);font-size:15px;line-height:1.5}
.x-log{list-style:none;padding:0;margin:24px 0;max-width:720px}
.x-log>li{display:grid;grid-template-columns:110px 1fr;gap:16px;padding:18px 0;border-top:1px solid var(--line)}
.x-v b{display:block;font-size:1.2rem}
.x-v span{font-size:14px}
.x-log ul{margin:0;padding-left:18px;line-height:1.6}
@media (max-width:520px){.x-log>li{grid-template-columns:1fr;gap:6px}}
.ch-video{margin:22px 0 6px}
.ch-video video{display:block;width:100%;aspect-ratio:16/9;border-radius:16px;background:#0d1220;border:1px solid var(--line)}
.ch-video figcaption{font-size:14px;color:var(--muted);margin-top:8px}

/* license line + prompt teaser */
.lic{max-width:760px;margin:26px auto 0;font-size:13px;color:var(--muted);text-align:center;border-top:1px solid var(--line);padding-top:12px}
.prompt.pw-teaser{border-style:dashed;border-color:var(--accent)}
@media print{.lic{display:block}}

/* pilot chapters: structure blocks */
.pilot-flag{display:inline-block;background:var(--warn-soft);color:var(--ink);font-size:13px;font-weight:600;border-radius:999px;padding:4px 12px;margin:0 0 8px}
.goal{border-left:4px solid var(--accent);background:var(--surface);border-radius:12px;padding:14px 18px;margin:18px 0;max-width:68ch}
.goal b{display:block;margin-bottom:4px}
.goal ul{margin:6px 0 0;padding-left:20px}
.demo{position:relative;border:1px solid var(--line);border-radius:14px;padding:30px 20px 14px;margin:22px 0;max-width:68ch;background:var(--surface)}
.demo:before{content:attr(data-label);position:absolute;top:-11px;left:16px;background:var(--warn);color:#111;font-size:12px;font-weight:700;letter-spacing:.02em;border-radius:999px;padding:3px 10px}
.result{border:2px solid var(--good);border-radius:14px;padding:14px 18px;margin:26px 0;max-width:68ch}
.result b{color:var(--good)}
.checked{font-size:13px;color:var(--muted)}
.pack-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-top:12px}
.otrack{width:100%;border-collapse:collapse;font-size:14px}
.otrack td,.otrack th{border-bottom:1px solid var(--line);padding:6px 4px;text-align:left;vertical-align:top}
.otrack input,.otrack select{width:100%;min-width:0;font-size:14px;padding:6px}
.ohint{font-size:13px;color:var(--muted);margin-top:4px}
.ohint.warn{color:var(--accent-ink)}

.skip-link{position:absolute;left:8px;top:-60px;z-index:100;background:var(--surface);color:var(--ink);padding:10px 14px;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,.2);font-weight:700}.skip-link:focus{top:8px}
#view:focus{outline:none}

video:focus-visible,[tabindex]:focus-visible,summary:focus-visible,select:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
.ch-video video:focus,.ch-video video:focus-within{outline:3px solid var(--blue);outline-offset:2px}
.mistakes{list-style:none;padding:0;margin:12px 0;max-width:68ch;display:grid;gap:8px}
.mistakes li{border-left:4px solid var(--warn);background:var(--warn-soft);border-radius:8px;padding:10px 14px}
.mistakes li b{display:block}
.pp{border:1px solid var(--line);border-radius:12px;background:var(--surface);margin:0 0 10px;max-width:72ch}
.pp>summary{cursor:pointer;padding:12px 16px;display:grid;gap:2px;list-style-position:outside}
.pp>summary span{font-size:14px;color:var(--muted)}
.pp-body{padding:0 16px 14px}
pre.tpl{white-space:pre-wrap;overflow-wrap:anywhere;background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:12px 14px;font:inherit;font-size:14px;margin:10px 0 6px;max-width:68ch}
.tpl-copy{margin:0 0 12px}