:root{
  --bg:#F4EEE2; --surface:#FBF7EE; --card:#FFFFFF;
  --ink:#211F1A; --muted:#6E665A; --faint:#94897A;
  --line:#E6DCC9; --line-strong:#D8CBB2;
  --accent:#B14A26; --accent-soft:#F0DCCF;
  --teal:#1E4A40; --teal-soft:#DCE8E0;
  --gold:#A4742A;
  --shadow:0 1px 2px rgba(60,45,20,.05),0 8px 30px rgba(60,45,20,.06);
}
html[data-theme="dark"]{
  --bg:#16140F; --surface:#1E1B15; --card:#231F18;
  --ink:#F2ECDF; --muted:#A99E8B; --faint:#82786A;
  --line:#332D23; --line-strong:#453D2E;
  --accent:#E0814F; --accent-soft:#3A2418;
  --teal:#7FC0AD; --teal-soft:#1C2E29;
  --gold:#D2A661;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 10px 34px rgba(0,0,0,.34);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--bg);color:var(--ink);
  font-family:'Hanken Grotesk',sans-serif;
  font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased;
  background-image:radial-gradient(var(--line) 0.5px,transparent 0.5px);
  background-size:22px 22px;
}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

.shell{display:flex;min-height:100vh}
.sidebar{
  width:320px;flex:none;position:sticky;top:0;height:100vh;
  background:var(--surface);border-right:1px solid var(--line);
  display:flex;flex-direction:column;overflow:hidden;
}
.main{flex:1;min-width:0;padding:0 0 120px}
.wrap{max-width:760px;margin:0 auto;padding:0 28px}

.brand{padding:26px 24px 18px;border-bottom:1px solid var(--line);display:block;color:var(--ink)}
.brand:hover{text-decoration:none}
.brand .kicker{font-family:'IBM Plex Mono',monospace;font-size:10.5px;letter-spacing:.18em;text-transform:uppercase;color:var(--accent);font-weight:600}
.brand h1{font-family:'Fraunces',serif;font-weight:600;font-size:23px;line-height:1.1;margin-top:8px;letter-spacing:-.01em}
.brand p{font-size:12.5px;color:var(--muted);margin-top:7px}
.searchbox{padding:14px 18px;border-bottom:1px solid var(--line)}
.searchbox input{width:100%;background:var(--bg);border:1px solid var(--line-strong);border-radius:9px;padding:9px 12px;font-family:inherit;font-size:13.5px;color:var(--ink)}
.searchbox input:focus{outline:none;border-color:var(--accent)}
.navlist{flex:1;overflow-y:auto;padding:10px 12px 24px}
.navitem{display:flex;gap:11px;align-items:flex-start;padding:10px 12px;border-radius:10px;cursor:pointer;color:var(--ink);transition:background .15s;position:relative}
.navitem:hover{background:var(--bg);text-decoration:none}
.navitem.active{background:var(--accent-soft)}
.navitem.dim{opacity:.3}
.navitem .num{font-family:'IBM Plex Mono',monospace;font-size:11px;color:var(--faint);padding-top:3px;min-width:20px;font-weight:600}
.navitem.active .num{color:var(--accent)}
.navitem .nt{font-size:13.5px;font-weight:600;line-height:1.3}
.navitem .ns{font-size:11.5px;color:var(--muted);margin-top:1px;font-weight:400}
.navitem .dot{position:absolute;right:11px;top:13px;width:8px;height:8px;border-radius:50%;border:1.5px solid var(--line-strong)}
.navitem .dot.done{background:var(--gold);border-color:var(--gold)}
.progresswrap{padding:14px 20px;border-top:1px solid var(--line);background:var(--surface)}
.progresswrap .lbl{display:flex;justify-content:space-between;font-family:'IBM Plex Mono',monospace;font-size:10.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin-bottom:7px}
.bar{height:6px;background:var(--line);border-radius:6px;overflow:hidden}
.bar > i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--gold),var(--accent));border-radius:6px;transition:width .4s ease}

.topbar{display:none;position:sticky;top:0;z-index:40;background:var(--surface);border-bottom:1px solid var(--line);padding:11px 16px;align-items:center;gap:12px}
.topbar h2{font-family:'Fraunces',serif;font-size:16px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.menubtn{background:var(--bg);border:1px solid var(--line-strong);border-radius:8px;width:38px;height:38px;font-size:18px;cursor:pointer;color:var(--ink);flex:none}
.themebtn{margin-left:auto;background:var(--bg);border:1px solid var(--line-strong);border-radius:8px;height:38px;padding:0 12px;cursor:pointer;color:var(--ink);font-size:13px;font-family:'IBM Plex Mono',monospace;flex:none}
.scrim{display:none;position:fixed;inset:0;background:rgba(20,15,5,.4);z-index:45}

.hero{padding:78px 0 40px;border-bottom:1px solid var(--line)}
.hero .eyebrow{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.2em;text-transform:uppercase;color:var(--accent);font-weight:600}
.hero h1{font-family:'Fraunces',serif;font-weight:600;font-size:clamp(34px,6vw,56px);line-height:1.02;letter-spacing:-.02em;margin:18px 0 0}
.hero h1 em{font-style:italic;color:var(--accent)}
.hero .lede{font-size:19px;color:var(--muted);margin-top:22px;max-width:620px}
.metarow{display:flex;flex-wrap:wrap;gap:26px;margin-top:34px;padding-top:26px;border-top:1px dashed var(--line-strong)}
.metarow .m .k{font-family:'Fraunces',serif;font-size:28px;font-weight:600;color:var(--ink)}
.metarow .m .v{font-size:12px;color:var(--muted);font-family:'IBM Plex Mono',monospace;letter-spacing:.05em;text-transform:uppercase;margin-top:2px}

.modgrid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px;margin-top:38px}
.modcard{display:block;border:1px solid var(--line);border-radius:14px;padding:18px 18px;background:var(--card);box-shadow:var(--shadow);color:var(--ink);transition:transform .15s,border-color .15s}
.modcard:hover{transform:translateY(-3px);border-color:var(--accent);text-decoration:none}
.modcard .mn{font-family:'IBM Plex Mono',monospace;font-size:11px;color:var(--accent);font-weight:600}
.modcard .mt{font-family:'Fraunces',serif;font-size:19px;font-weight:600;margin-top:6px;line-height:1.15}
.modcard .md{font-size:13px;color:var(--muted);margin-top:6px}

.mhead{padding-top:46px}
.mhead .tag{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--accent);font-weight:600}
.mhead h2{font-family:'Fraunces',serif;font-weight:600;font-size:clamp(30px,5vw,44px);line-height:1.05;letter-spacing:-.02em;margin:12px 0 0}
.mhead .sub{font-size:18px;color:var(--muted);margin-top:16px;max-width:640px}
.content h3{font-family:'Fraunces',serif;font-weight:600;font-size:25px;margin:42px 0 4px;letter-spacing:-.01em}
.content h4{font-family:'Hanken Grotesk',sans-serif;font-weight:700;font-size:17px;margin:26px 0 6px}
.content p{margin:14px 0;color:var(--ink)}
.content ul,.content ol{margin:14px 0 14px 4px;padding-left:22px}
.content li{margin:8px 0}
.content li::marker{color:var(--accent)}
.content strong{font-weight:700}
.lead-in{font-size:19px;line-height:1.55;color:var(--ink)}
.lead-in::first-letter{font-family:'Fraunces',serif;font-size:58px;float:left;line-height:.78;padding:6px 10px 0 0;color:var(--accent);font-weight:600}

.box{border-radius:14px;padding:20px 22px;margin:26px 0;border:1px solid var(--line);background:var(--card);box-shadow:var(--shadow)}
.box .bt{font-family:'IBM Plex Mono',monospace;font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;font-weight:600;margin-bottom:8px}
.box p{margin:8px 0 0}
.box.orelis{background:var(--teal-soft);border-color:transparent}
.box.orelis .bt{color:var(--teal)}
.box.key{background:var(--accent-soft);border-color:transparent}
.box.key .bt{color:var(--accent)}
.box.warn{border-left:3px solid var(--accent)}
.box.warn .bt{color:var(--accent)}

.exercise{border:1px dashed var(--line-strong);border-radius:14px;padding:18px 20px;margin:20px 0;background:var(--surface)}
.exercise .q{font-weight:700;display:flex;gap:10px}
.exercise .q .ix{font-family:'IBM Plex Mono',monospace;color:var(--accent);font-size:14px}
.exercise details{margin-top:10px}
.exercise summary{cursor:pointer;font-family:'IBM Plex Mono',monospace;font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);font-weight:600;list-style:none}
.exercise summary::-webkit-details-marker{display:none}
.exercise summary::before{content:"\\25B8  "}
.exercise details[open] summary::before{content:"\\25BE  "}
.exercise .ans{margin-top:10px;padding-top:10px;border-top:1px solid var(--line);color:var(--muted);font-size:15.5px}

.resources{margin:30px 0 0;border-top:1px solid var(--line);padding-top:22px}
.resources .rh{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);font-weight:600;margin-bottom:14px}
.res{display:block;border:1px solid var(--line);border-radius:12px;padding:14px 16px;margin-bottom:10px;background:var(--card);transition:border-color .15s,transform .15s}
.res:hover{border-color:var(--accent);text-decoration:none;transform:translateX(3px)}
.res .rt{font-weight:700;color:var(--ink);font-size:15px}
.res .rd{font-size:13px;color:var(--muted);margin-top:2px}
.res .rmeta{font-family:'IBM Plex Mono',monospace;font-size:10.5px;color:var(--accent);margin-top:6px;letter-spacing:.04em}
.free{display:inline-block;font-family:'IBM Plex Mono',monospace;font-size:9.5px;letter-spacing:.1em;background:var(--teal-soft);color:var(--teal);padding:2px 7px;border-radius:5px;font-weight:600;vertical-align:middle;margin-left:6px}

.foot{margin-top:48px;padding-top:26px;border-top:1px solid var(--line);display:flex;flex-wrap:wrap;gap:14px;align-items:center}
.complete{background:var(--ink);color:var(--bg);border:none;border-radius:10px;padding:12px 20px;font-family:'Hanken Grotesk',sans-serif;font-weight:700;font-size:14px;cursor:pointer;transition:opacity .15s}
.complete:hover{opacity:.88}
.complete.done{background:var(--teal);color:#fff}
.nextprev{margin-left:auto;display:flex;gap:10px}
.np{border:1px solid var(--line-strong);background:var(--surface);border-radius:10px;padding:11px 16px;font-size:13px;font-weight:600;cursor:pointer;color:var(--ink)}
.np:hover{border-color:var(--accent);text-decoration:none}
.np.disabled{opacity:.35;pointer-events:none}

.disclaimer{font-size:13px;color:var(--faint);margin-top:30px;line-height:1.55;border-top:1px dashed var(--line-strong);padding-top:18px}
.lead-para{padding-top:34px}

.gloss dt{font-family:'Fraunces',serif;font-weight:600;font-size:18px;margin-top:22px;color:var(--ink)}
.gloss dd{margin:4px 0 0;color:var(--muted);font-size:15.5px}

@media(max-width:880px){
  .sidebar{position:fixed;left:0;top:0;z-index:50;transform:translateX(-100%);transition:transform .28s ease;width:300px;box-shadow:var(--shadow)}
  .sidebar.open{transform:none}
  .topbar{display:flex}
  .scrim.open{display:block}
  .wrap{padding:0 20px}
  .hero{padding:34px 0 30px}
  .lead-in::first-letter{font-size:48px}
  .modgrid{grid-template-columns:1fr}
}