:root{
    --bg:#eef6f6; --bg-raised:#f8fcfc; --bg-inverse:#004e5a;
    --text:#0d2a30; --text-muted:#4a6a70; --text-on-inverse:#eafaf8; --text-on-inverse-muted:#a9d3d6;
    --accent:#016c7c; --accent-on-inverse:#55d193; --line:#c6dfe1; --line-strong:#9fc4c8; --line-on-inverse:rgba(234,250,248,0.16);
    --paper-shadow:0 1px 2px rgba(0,40,48,.10), 0 18px 40px -22px rgba(0,40,48,.45);
    --font-display:"Iowan Old Style","Sitka Small","Palatino Linotype",Palatino,"Book Antiqua",Georgia,serif;
    --font-body:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
    --font-mono:"Courier New",ui-monospace,"Cascadia Mono",Consolas,monospace;
  }
  @media (prefers-color-scheme: dark){
    :root:not([data-theme="light"]){
      color-scheme:dark; --bg:#06242a; --bg-raised:#0b3037; --bg-inverse:#003a44;
      --text:#e3f4f3; --text-muted:#93b9bd; --accent:#46e9d8; --line:rgba(227,244,243,0.14); --line-strong:rgba(227,244,243,0.24);
      --paper-shadow:0 1px 2px rgba(0,0,0,.4), 0 18px 40px -22px rgba(0,0,0,.8);
    }
  }
  :root[data-theme="dark"]{
    color-scheme:dark; --bg:#06242a; --bg-raised:#0b3037; --bg-inverse:#003a44;
    --text:#e3f4f3; --text-muted:#93b9bd; --accent:#46e9d8; --line:rgba(227,244,243,0.14); --line-strong:rgba(227,244,243,0.24);
    --paper-shadow:0 1px 2px rgba(0,0,0,.4), 0 18px 40px -22px rgba(0,0,0,.8);
  }
  *{box-sizing:border-box;}
  [hidden]{display:none !important;}
  body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased;}
  a{color:inherit;}
  :focus-visible{outline:2px solid var(--accent);outline-offset:2px;}

  header.site{position:sticky;top:env(safe-area-inset-top,0px);z-index:20;background:var(--bg-inverse);color:var(--text-on-inverse);border-bottom:1px solid var(--line-on-inverse);}
  .bar{max-width:1440px;margin:0 auto;padding:14px clamp(16px,3vw,40px);display:flex;align-items:center;justify-content:space-between;gap:16px;}
  .brand{display:flex;flex-direction:column;gap:4px;line-height:1;text-decoration:none;}
  .brand .mark{font-family:var(--font-display);font-size:1.4rem;letter-spacing:.06em;font-weight:600;color:var(--accent-on-inverse);white-space:nowrap;}
  .brand .sub{font-family:var(--font-mono);font-size:.62rem;letter-spacing:.12em;text-transform:uppercase;color:var(--text-on-inverse-muted);}.bar nav a:hover{border-color:var(--accent-on-inverse);color:var(--accent-on-inverse);}

  .layout{max-width:1440px;margin:0 auto;padding:clamp(20px,3vw,36px) clamp(16px,3vw,40px) 64px;
    display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:clamp(24px,3vw,44px);align-items:start;}

  /* ---------- Guide (left) ---------- */
  .guide-head{max-width:1000px;margin:0 auto 20px;display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:16px 24px;}
  .crumbs{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--text-muted);display:flex;align-items:center;gap:8px;}
  .crumbs svg{width:14px;height:14px;color:var(--accent);}
  .guide-head h1{font-family:var(--font-display);font-weight:600;font-size:clamp(1.7rem,1.2vw + 1.2rem,2.3rem);line-height:1.15;margin:8px 0 6px;text-wrap:balance;}
  .guide-head .summary{margin:0;color:var(--text-muted);max-width:62ch;}
  .meta{margin:8px 0 0;font-size:.82rem;color:var(--text-muted);}
  .actions{display:flex;flex-wrap:wrap;gap:10px;}
  .btn{display:inline-flex;align-items:center;gap:8px;font:600 .92rem/1.2 var(--font-body);padding:12px 18px;border-radius:2px;text-decoration:none;cursor:pointer;border:1px solid transparent;white-space:nowrap;}
  .btn svg{width:16px;height:16px;}
  .btn-primary{background:#016c7c;color:#fff;}
  .btn-primary:hover{background:#004e5a;}
  .btn-outline{border-color:var(--line-strong);color:var(--text);background:transparent;}
  .btn-outline:hover{border-color:var(--accent);color:var(--accent);}

  .viewer{max-width:1000px;margin:0 auto;display:flex;flex-direction:column;gap:22px;}
  .page{position:relative;background:#fff;box-shadow:var(--paper-shadow);border-radius:2px;overflow:hidden;aspect-ratio:210 / 297;width:100%;}
  .page canvas{display:block;width:100%;height:100%;}
  .page .pno{position:absolute;right:10px;bottom:8px;font:600 .7rem var(--font-mono);color:#4a6a70;background:rgba(255,255,255,.85);padding:2px 6px;border-radius:2px;}
  .viewer-note{max-width:1000px;margin:0 auto;padding:22px;border:1px dashed var(--line-strong);border-radius:2px;color:var(--text-muted);background:var(--bg-raised);}
  .viewer-note strong{color:var(--text);}
  .loading{display:flex;align-items:center;justify-content:center;color:#4a6a70;font-size:.9rem;}

  .pager{max-width:1000px;margin:24px auto 0;display:grid;grid-template-columns:1fr 1fr;gap:16px;}
  .pager a{display:flex;flex-direction:column;gap:2px;padding:14px 16px;border:1px solid var(--line);background:var(--bg-raised);text-decoration:none;border-radius:2px;}
  .pager a:hover{border-color:var(--accent);}
  .pager .dir{font-family:var(--font-mono);font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--text-muted);}
  .pager .t{font-weight:700;color:var(--accent);}
  .pager .next{text-align:right;grid-column:2;}

  /* ---------- Guide list (right) ---------- */
  .shelf{position:sticky;top:96px;background:var(--bg-raised);border:1px solid var(--line);border-radius:4px;padding:20px 18px;max-height:calc(100vh - 120px);overflow:auto;}
  .shelf h2{font-family:var(--font-display);font-weight:600;font-size:1.25rem;margin:0 0 4px;}
  .shelf > p{margin:0 0 14px;font-size:.85rem;color:var(--text-muted);}
  .group{margin:0 0 14px;}
  .group h3{display:flex;align-items:center;gap:7px;margin:0 0 6px;font-family:var(--font-mono);font-size:.7rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--text-muted);}
  .group h3 svg{width:13px;height:13px;color:var(--accent);}
  .group ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:2px;}
  .group a{display:block;padding:8px 10px;border-radius:3px;text-decoration:none;font-size:.93rem;border-left:3px solid transparent;}
  .group a:hover{background:var(--bg);}
  .group a[aria-current="page"]{background:var(--bg);border-left-color:var(--accent);font-weight:700;color:var(--accent);}
  .shelf .cta{margin-top:8px;padding-top:14px;border-top:1px solid var(--line);font-size:.85rem;color:var(--text-muted);}
  .shelf .cta a{color:var(--accent);font-weight:700;}

  @media (max-width:1060px){
    .layout{grid-template-columns:1fr;}
    .shelf{position:static;max-height:none;}
  }
  @media (max-width:560px){
    .pager{grid-template-columns:1fr;}
    .pager .next{grid-column:1;}
  }

  /* ---------- Library listing (cards) ---------- */
  .lib-hero{background:var(--bg-inverse);color:var(--text-on-inverse);}
  .lib-hero .in{max-width:1440px;margin:0 auto;padding:clamp(36px,6vw,72px) clamp(16px,3vw,40px);}
  .lib-hero .eyebrow{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.14em;text-transform:uppercase;color:var(--accent-on-inverse);margin:0 0 12px;}
  .lib-hero h1{font-family:var(--font-display);font-weight:600;font-size:clamp(2rem,2vw + 1.4rem,3.2rem);line-height:1.1;margin:0 0 14px;max-width:22ch;}
  .lib-hero p{margin:0;max-width:56ch;color:var(--text-on-inverse-muted);}
  .lib-body{max-width:1440px;margin:0 auto;padding:clamp(28px,4vw,56px) clamp(16px,3vw,40px) 72px;}
  .lgroup{margin:0 0 clamp(32px,4vw,52px);}
  .lgroup h2{display:flex;align-items:center;gap:10px;margin:0 0 18px;padding-bottom:12px;border-bottom:1px solid var(--line-strong);font-family:var(--font-mono);font-size:.76rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--accent);}
  .lgroup h2 svg{width:16px;height:16px;}
  .lgrid{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(290px,1fr));column-gap:20px;row-gap:0;}
  /* Each card spans four rows of the shared grid (label, title, description, links), so a row of cards lines up
     whatever the length of each title. Browsers without subgrid fall back to equal-height cards. */
  .lcard{padding-bottom:20px;display:flex;}
  .lcard article{flex:1;display:flex;flex-direction:column;gap:10px;padding:24px 22px 18px;background:var(--bg-raised);border:1px solid var(--line);border-radius:2px;}
  @supports (grid-template-rows:subgrid){
    .lcard{display:grid;grid-row:span 4;grid-template-rows:subgrid;}
    .lcard article{display:grid;grid-row:1 / span 4;grid-template-rows:subgrid;row-gap:10px;align-content:start;}
    .lcard .row{align-self:end;}
  }
  .lcard article:hover,.lcard article:focus-within{border-color:var(--accent);}
  .lcard .tag{margin:0;font-family:var(--font-mono);font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;color:var(--text-muted);}
  .lcard h3{margin:0;font-family:var(--font-display);font-weight:600;font-size:1.3rem;line-height:1.2;}
  .lcard h3 a{text-decoration:none;color:var(--text);}
  .lcard h3 a:hover{color:var(--accent);}
  .lcard p{margin:0;color:var(--text-muted);font-size:.95rem;flex:1;}
  .lcard .row{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;padding-top:12px;border-top:1px solid var(--line);font-size:.8rem;color:var(--text-muted);}
  .lcard .acts{display:flex;gap:14px;}
  .lcard .acts a{font-weight:700;color:var(--accent);text-decoration:none;}
  .lcard .acts a:hover{text-decoration:underline;}
  .lib-cta{color:var(--text-muted);}
  .lib-cta a{color:var(--accent);font-weight:700;}


  /* ---------- Site menu (same items as the home page) ---------- */
  .bar nav.links{display:flex;gap:clamp(14px,2vw,30px);}
  .bar nav.links a{text-decoration:none;font-size:1rem;font-weight:500;color:var(--text-on-inverse-muted);border-bottom:1px solid transparent;padding-bottom:3px;white-space:nowrap;transition:color .15s,border-color .15s;}
  .bar nav.links a:hover,.bar nav.links a:focus-visible,.bar nav.links a[aria-current="page"]{color:var(--text-on-inverse);border-color:var(--accent-on-inverse);}
  .bar nav.links a.in-menu{display:none;}
  .nav-right{display:flex;align-items:center;gap:20px;}
  .nav-phone{font-weight:700;letter-spacing:.02em;color:var(--text-on-inverse);text-decoration:none;white-space:nowrap;font-variant-numeric:tabular-nums;}
  header.site .btn-primary{background:var(--accent-on-inverse);color:var(--bg-inverse);padding:12px 22px;}
  header.site .btn-primary:hover{background:var(--text-on-inverse);}
  .portal-text{font-size:1rem;font-weight:600;color:var(--accent-on-inverse);text-decoration:none;white-space:nowrap;border-bottom:1px solid transparent;padding-bottom:2px;}
  .portal-text:hover,.portal-text:focus-visible{color:var(--text-on-inverse);border-color:var(--accent-on-inverse);}
  .menu-toggle{display:none;background:none;border:1px solid var(--line-on-inverse);color:var(--text-on-inverse);width:40px;height:40px;align-items:center;justify-content:center;border-radius:2px;cursor:pointer;}
  @media (max-width:860px){
    .bar nav.links{position:fixed;inset:68px 0 0 0;background:var(--bg-inverse);flex-direction:column;padding:24px;gap:18px;transform:translateY(-8px);opacity:0;pointer-events:none;transition:opacity .18s ease,transform .18s ease;border-top:1px solid var(--line-on-inverse);}
    .bar nav.links.open{opacity:1;transform:none;pointer-events:auto;}
    .bar nav.links a{font-size:1.05rem;padding-bottom:14px;border-bottom:1px solid var(--line-on-inverse);}
    .bar nav.links a.in-menu{display:block;}
    .portal-text,header.site .btn-primary{display:none;}
    .menu-toggle{display:flex;}
  }