:root{
    --bg:#f5f7f4;
    --surface:#ffffff;
    --surface-2:#eef2ee;
    --ink:#043529;
    --ink-soft:#325b4e;
    --primary:#0c936b;
    --primary-light:#70d6b1;
    --primary-wash:#e4f5ee;
    --border:#d9e3dd;
    --neutral-mid:#6b6f8f;
    --text:#12201b;
    --text-mute:#4d5c56;
    --red:#e74a41;
    --yellow:#c98f02;
    --pink:#e83c96;
    --blue:#4583d4;
    --shadow:0 1px 2px rgba(4,53,41,.06), 0 8px 24px -12px rgba(4,53,41,.18);
    /* Fixed brand-panel pair: intentionally constant across themes (credential/stamp
       motif — hero, spec sheets, badges). Never redefined in the dark-mode blocks. */
    --panel-bg:#043529;
    --panel-text:#f2faf6;
    --panel-text-mute:#cfe6db;
    --panel-accent:#70d6b1;
    color-scheme:light;
  }
  @media (prefers-color-scheme: dark){
    :root:not([data-theme="light"]){
      --bg:#0b1310;
      --surface:#121c18;
      --surface-2:#182620;
      --ink:#eaf6f0;
      --ink-soft:#bcd6c9;
      --primary:#3fcf9c;
      --primary-light:#1e5c45;
      --primary-wash:#173226;
      --border:#213a30;
      --neutral-mid:#98a0c2;
      --text:#eef3f0;
      --text-mute:#a9bab2;
      --red:#ff8079;
      --yellow:#f0c24a;
      --pink:#ef79b8;
      --blue:#79a9e8;
      --shadow:0 1px 2px rgba(0,0,0,.3), 0 8px 24px -12px rgba(0,0,0,.5);
      color-scheme:dark;
    }
  }
  :root[data-theme="dark"]{
    --bg:#0b1310;
    --surface:#121c18;
    --surface-2:#182620;
    --ink:#eaf6f0;
    --ink-soft:#bcd6c9;
    --primary:#3fcf9c;
    --primary-light:#1e5c45;
    --primary-wash:#173226;
    --border:#213a30;
    --neutral-mid:#98a0c2;
    --text:#eef3f0;
    --text-mute:#a9bab2;
    --red:#ff8079;
    --yellow:#f0c24a;
    --pink:#ef79b8;
    --blue:#79a9e8;
    --shadow:0 1px 2px rgba(0,0,0,.3), 0 8px 24px -12px rgba(0,0,0,.5);
    color-scheme:dark;
  }

  *{box-sizing:border-box;}
  body{
    background:var(--bg);
    color:var(--text);
    font-family:'Geist', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    -webkit-font-smoothing:antialiased;
    padding-inline:0;
  }
  .mono{font-family:'Geist Mono','SFMono-Regular',Consolas,monospace;}
  h1,h2,h3,h4{color:var(--ink);text-wrap:balance;margin:0;font-weight:700;letter-spacing:-.01em;}
  p{margin:0;line-height:1.6;}
  a{color:inherit;}
  img,svg{max-width:100%;}
  button{font-family:inherit;}

  .wrap{max-width:1040px;margin-inline:auto;padding-inline:20px;}

  /* ---------- Nav ---------- */
  header.site{
    position:sticky;top:env(safe-area-inset-top,0px);z-index:40;
    background:var(--surface);border-bottom:1px solid var(--border);
    padding-top:env(safe-area-inset-top,0px);
  }
  .nav-inner{display:flex;align-items:center;gap:18px;padding-block:12px;}
  .logo{flex:0 0 auto;display:flex;align-items:center;height:22px;color:var(--ink);}
  .logo svg{height:100%;width:auto;display:block;}
  nav.tabs{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none;flex:1 1 auto;}
  nav.tabs::-webkit-scrollbar{display:none;}
  nav.tabs a{
    flex:0 0 auto;font-size:13.5px;font-weight:600;color:var(--text-mute);
    padding:7px 12px;border-radius:999px;white-space:nowrap;text-decoration:none;
    transition:background .15s,color .15s;
  }
  nav.tabs a:hover{background:var(--surface-2);color:var(--ink);}
  nav.tabs a.active{background:var(--primary-wash);color:var(--primary);}

  /* ---------- Pages ---------- */
  main{padding-block:36px 64px;}
  .page{display:flex;flex-direction:column;gap:48px;}

  .eyebrow{
    display:inline-flex;align-items:center;gap:8px;font-family:'Geist Mono',monospace;
    font-size:11.5px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;
    color:var(--primary);
  }
  .eyebrow::before{content:"";width:7px;height:7px;border-radius:2px;background:var(--primary);display:inline-block;}

  /* Hero */
  .hero{
    position:relative;overflow:hidden;background:var(--panel-bg);border-radius:20px;
    padding:44px 28px;color:var(--panel-text);isolation:isolate;
  }
  .hero .iso-watermark{position:absolute;right:-40px;top:-40px;width:280px;height:280px;opacity:.14;z-index:-1;}
  .hero .eyebrow{color:var(--panel-accent);}
  .hero .eyebrow::before{background:var(--panel-accent);}
  .hero h1{color:#fff;font-size:clamp(28px,4.6vw,44px);margin-top:10px;max-width:14ch;}
  .hero p.sub{color:var(--panel-text-mute);max-width:52ch;margin-top:14px;font-size:16px;}
  .hero .cta-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:26px;}

  .btn{
    display:inline-flex;align-items:center;gap:8px;border-radius:10px;
    padding:11px 18px;font-weight:600;font-size:14.5px;text-decoration:none;
    border:1px solid transparent;cursor:pointer;transition:transform .12s,filter .12s;
  }
  .btn:active{transform:translateY(1px);}
  .btn-primary{background:var(--primary);color:#062017;}
  .btn-primary:hover{filter:brightness(1.06);}
  .btn-ghost{background:rgba(255,255,255,.08);color:#fff;border-color:rgba(255,255,255,.28);}
  .btn-ghost:hover{background:rgba(255,255,255,.16);}
  .btn-outline{background:transparent;color:var(--primary);border-color:var(--primary);}
  .btn-outline:hover{background:var(--primary-wash);}

  section{display:flex;flex-direction:column;gap:16px;}
  .lede{max-width:64ch;color:var(--text-mute);font-size:15.5px;}

  /* Module grid */
  .grid-modules{display:grid;grid-template-columns:repeat(2,1fr);gap:14px;}
  @media (max-width:640px){.grid-modules{grid-template-columns:1fr;}}
  .card-module{
    background:var(--surface);border:1px solid var(--border);border-radius:16px;
    padding:20px;display:flex;flex-direction:column;gap:12px;box-shadow:var(--shadow);
    border-top:3px solid var(--accent,var(--primary));
  }
  .mod-badge{
    width:34px;height:34px;border-radius:9px;display:flex;align-items:center;justify-content:center;
    font-family:'Geist Mono',monospace;font-weight:700;font-size:14px;color:#fff;background:var(--accent,var(--primary));
  }
  .card-module h3{font-size:17px;}
  .card-module .desc{font-size:14px;color:var(--text-mute);}
  .spec-chips{display:flex;gap:8px;flex-wrap:wrap;margin-top:2px;}
  .chip{
    font-family:'Geist Mono',monospace;font-size:11.5px;font-weight:600;color:var(--ink-soft);
    background:var(--surface-2);border:1px solid var(--border);border-radius:999px;padding:4px 9px;
  }
  .card-module .btn{margin-top:4px;align-self:flex-start;}

  /* Generic info card */
  .card{
    background:var(--surface);border:1px solid var(--border);border-radius:16px;
    padding:22px;box-shadow:var(--shadow);
  }

  /* Placeholder card */
  .placeholder{
    border:1.5px dashed var(--border);border-radius:16px;padding:20px;
    display:flex;gap:14px;align-items:flex-start;background:var(--surface-2);
  }
  .placeholder .dot{
    flex:0 0 auto;width:28px;height:28px;border-radius:8px;background:var(--surface);
    border:1px solid var(--border);display:flex;align-items:center;justify-content:center;
    font-family:'Geist Mono',monospace;font-size:12px;color:var(--neutral-mid);
  }
  .placeholder strong{color:var(--ink);font-size:14px;}
  .placeholder p{font-size:13.5px;color:var(--text-mute);margin-top:4px;}

  /* two column layout */
  .two-col{display:grid;grid-template-columns:1.3fr 1fr;gap:16px;align-items:start;}
  @media (max-width:720px){.two-col{grid-template-columns:1fr;}}

  /* Module detail page */
  .mod-hero{border-radius:20px;padding:30px 26px;border:1px solid var(--border);background:var(--surface);}
  .mod-hero .top{display:flex;align-items:center;gap:12px;}
  .mod-number{
    font-family:'Geist Mono',monospace;font-weight:700;font-size:13px;color:#fff;
    background:var(--accent,var(--primary));width:40px;height:40px;border-radius:10px;
    display:flex;align-items:center;justify-content:center;flex:0 0 auto;
  }
  .mod-hero h1{font-size:clamp(24px,3.6vw,32px);margin-top:14px;}
  .mod-hero .sub{color:var(--text-mute);font-size:15px;margin-top:8px;max-width:58ch;}

  .spec-card{
    background:var(--panel-bg);color:var(--panel-text);border-radius:16px;padding:20px;
    display:grid;grid-template-columns:repeat(2,1fr);gap:16px 20px;
  }
  .spec-card .item .k{font-family:'Geist Mono',monospace;font-size:10.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--panel-accent);}
  .spec-card .item .v{font-family:'Geist Mono',monospace;font-size:19px;font-weight:600;margin-top:4px;color:#fff;}

  .back-link{display:inline-flex;align-items:center;gap:6px;font-size:13.5px;font-weight:600;color:var(--primary);text-decoration:none;}
  .back-link:hover{text-decoration:underline;}

  .mod-nav{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;padding-top:6px;border-top:1px solid var(--border);margin-top:8px;}
  .mod-nav a{font-size:13.5px;font-weight:600;color:var(--ink);text-decoration:none;}
  .mod-nav a:hover{color:var(--primary);}

  /* FAQ */
  details.faq{
    background:var(--surface);border:1px solid var(--border);border-radius:14px;
    padding:16px 18px;
  }
  details.faq + details.faq{margin-top:10px;}
  details.faq summary{
    cursor:pointer;font-weight:600;font-size:15px;color:var(--ink);list-style:none;
    display:flex;justify-content:space-between;align-items:center;gap:12px;
  }
  details.faq summary::-webkit-details-marker{display:none;}
  details.faq summary::after{content:"+";font-family:'Geist Mono',monospace;font-size:18px;color:var(--primary);flex:0 0 auto;}
  details.faq[open] summary::after{content:"–";}
  details.faq .a{padding-top:10px;font-size:14.5px;color:var(--text-mute);line-height:1.65;}
  .faq-group h3{font-size:13px;text-transform:uppercase;letter-spacing:.08em;color:var(--neutral-mid);font-family:'Geist Mono',monospace;margin-bottom:12px;}

  /* Documentation table-ish */
  .doc-path{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:20px;}
  .doc-path h3{font-size:16px;display:flex;align-items:center;gap:10px;}
  .doc-path .path-index{
    font-family:'Geist Mono',monospace;font-size:12px;color:#fff;background:var(--panel-bg);
    width:24px;height:24px;border-radius:7px;display:flex;align-items:center;justify-content:center;
  }
  .doc-path ul{margin:12px 0 0;padding-left:0;list-style:none;display:flex;flex-direction:column;gap:8px;}
  .doc-path li{font-size:14px;color:var(--text-mute);padding-left:18px;position:relative;}
  .doc-path li::before{content:"—";position:absolute;left:0;color:var(--primary);}
  .fee{font-family:'Geist Mono',monospace;font-weight:600;color:var(--ink);}

  .timeline{display:flex;flex-direction:column;gap:0;border-left:2px solid var(--border);margin-left:6px;}
  .timeline .t-item{position:relative;padding:0 0 20px 22px;}
  .timeline .t-item:last-child{padding-bottom:0;}
  .timeline .t-item::before{content:"";position:absolute;left:-7px;top:2px;width:12px;height:12px;border-radius:50%;background:var(--primary);border:2px solid var(--surface);}
  .timeline .t-item .k{font-family:'Geist Mono',monospace;font-size:11.5px;color:var(--primary);font-weight:700;letter-spacing:.04em;}
  .timeline .t-item p{font-size:14px;color:var(--text-mute);margin-top:3px;}

  footer.site{border-top:1px solid var(--border);padding-block:22px;margin-top:12px;}
  footer.site .wrap{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;font-size:12.5px;color:var(--neutral-mid);}

  [hidden]{display:none!important;}

/* Multi-page site additions */
.back-link{margin-bottom:-8px;}