*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  :root {
    --bg: #0f1117;
    --bg2: #181c27;
    --bg3: #1e2333;
    --border: #2a3050;
    --text: #c9d1e0;
    --text-dim: #6b7899;
    --r7rs: #4a9eff;
    --r7rs-bg: #0d2040;
    --r7rs-border: #1a3a6a;
    --scm: #5ec48a;
    --scm-bg: #0a2018;
    --scm-border: #1a4a30;
    --srfi: #c792ea;
    --srfi-bg: #1a0d2e;
    --srfi-border: #3a1a5a;
    --tag-bg: #1e2a45;
    --tag-text: #8baad4;
    --heading: #e8edf5;
    --code: #b8c8e8;
  }

  body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
  }

  header {
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    padding: 24px 40px;
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 24px;
  }

  header h1 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--heading);
    letter-spacing: -0.02em;
  }

  header p { color: var(--text-dim); font-size: 0.875rem; }

  #search {
    margin-left: auto;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 7px 14px;
    color: var(--text);
    font-size: 0.875rem;
    width: 260px;
    outline: none;
    transition: border-color 0.15s;
  }

  #search:focus { border-color: var(--r7rs); }
  #search::placeholder { color: var(--text-dim); }

  .layout {
    display: flex;
    min-height: calc(100vh - 65px);
  }

  nav {
    width: 220px;
    flex-shrink: 0;
    background: var(--bg2);
    border-right: 1px solid var(--border);
    padding: 24px 0;
    position: sticky;
    top: 65px;
    height: calc(100vh - 65px);
    overflow-y: auto;
  }

  nav h2 {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-dim);
    padding: 0 20px 8px;
    margin-top: 20px;
  }

  nav h2:first-child { margin-top: 0; }

  nav a {
    display: block;
    padding: 5px 20px;
    font-size: 0.8rem;
    color: var(--text-dim);
    text-decoration: none;
    transition: color 0.1s, background 0.1s;
    border-left: 2px solid transparent;
  }

  nav a:hover { color: var(--text); background: var(--bg3); }

  nav a.r7rs { border-left-color: transparent; }
  nav a.r7rs:hover { color: var(--r7rs); border-left-color: var(--r7rs); }
  nav a.scm:hover { color: var(--scm); border-left-color: var(--scm); }
  nav a.srfi:hover { color: var(--srfi); border-left-color: var(--srfi); }

  main {
    flex: 1;
    padding: 40px;
    max-width: 1100px;
  }

  .section-heading {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
    margin-top: 40px;
  }

  .section-heading:first-child { margin-top: 0; }

  .section-heading h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--heading);
  }

  .section-heading hr {
    flex: 1;
    border: none;
    border-top: 1px solid var(--border);
  }

  .badge {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 2px 7px;
    border-radius: 4px;
  }

  .badge-r7rs { background: var(--r7rs-bg); color: var(--r7rs); border: 1px solid var(--r7rs-border); }
  .badge-scm  { background: var(--scm-bg);  color: var(--scm);  border: 1px solid var(--scm-border);  }
  .badge-srfi { background: var(--srfi-bg); color: var(--srfi); border: 1px solid var(--srfi-border); }

  .library {
    background: var(--bg2);
    border: 1px solid var(--border);
    border-radius: 10px;
    margin-bottom: 20px;
    overflow: hidden;
    transition: border-color 0.15s;
  }

  .library:hover { border-color: #3a4560; }

  .library.r7rs { border-left: 3px solid var(--r7rs); }
  .library.scm  { border-left: 3px solid var(--scm);  }
  .library.srfi { border-left: 3px solid var(--srfi); }

  .lib-header {
    display: flex;
    align-items: baseline;
    gap: 12px;
    padding: 16px 20px 12px;
    border-bottom: 1px solid var(--border);
    cursor: pointer;
    user-select: none;
  }

  .lib-name {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--heading);
  }

  .library.r7rs .lib-name { color: var(--r7rs); }
  .library.scm  .lib-name { color: var(--scm); }
  .library.srfi .lib-name { color: var(--srfi); }

  .lib-desc {
    font-size: 0.8rem;
    color: var(--text-dim);
  }

  .lib-count {
    margin-left: auto;
    font-size: 0.75rem;
    color: var(--text-dim);
    white-space: nowrap;
  }

  .lib-body {
    padding: 16px 20px;
  }

  .exports {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
  }

  .export {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 4px;
    background: var(--tag-bg);
    color: var(--tag-text);
    border: 1px solid transparent;
    transition: background 0.1s, color 0.1s;
    cursor: pointer;
  }

  .library.r7rs .export { background: var(--r7rs-bg); color: #6aafe8; border-color: var(--r7rs-border); }
  .library.scm  .export { background: var(--scm-bg);  color: #5ab87e; border-color: var(--scm-border); }
  .library.srfi .export { background: var(--srfi-bg); color: #c0a0e0; border-color: var(--srfi-border); }

  .export.highlight {
    background: #3a2800;
    color: #ffcc55;
    border-color: #5a4400;
  }

  .export.active { background: #3a2800; color: #ffcc55; border-color: #5a4400; }
  .library.r7rs .export.active { background: #0d2a50; color: #7ac0f0; border-color: #1e4a80; }
  .library.scm  .export.active { background: #0d2a18; color: #6edd90; border-color: #1a4a28; }
  .library.srfi .export.active { background: #200d38; color: #d4a8f0; border-color: #4a1a70; }

  .export.hidden { display: none; }

  .doc-panel {
    display: none;
    margin-top: 12px;
    padding: 12px;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.8rem;
    white-space: pre-wrap;
    color: var(--text);
  }

  .doc-panel.visible { display: block; }

  .library.hidden { display: none; }

  @media (max-width: 768px) {
    header { padding: 16px 20px; }
    main { padding: 20px; }
    nav { display: none; }
    #search { width: 180px; }
  }

  /* Per-library preamble (rendered from documentation/preambles/<id>.md) */
  .lib-preamble {
    margin-bottom: 14px;
    padding: 12px 14px;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.85rem;
    color: var(--text);
  }
  .lib-preamble h1, .lib-preamble h2, .lib-preamble h3 {
    font-size: 0.9rem;
    color: var(--heading);
    margin: 10px 0 6px;
  }
  .lib-preamble h1:first-child, .lib-preamble h2:first-child, .lib-preamble h3:first-child { margin-top: 0; }
  .lib-preamble p { margin: 6px 0; }
  .lib-preamble ul, .lib-preamble ol { margin: 6px 0 6px 20px; }
  .lib-preamble li { margin: 2px 0; }
  .lib-preamble a { color: var(--r7rs); text-decoration: none; }
  .lib-preamble a:hover { text-decoration: underline; }
  .lib-preamble code {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.8rem;
    background: var(--tag-bg);
    color: var(--code);
    padding: 1px 5px;
    border-radius: 4px;
  }
  .lib-preamble pre {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 10px 12px;
    overflow-x: auto;
    margin: 8px 0;
  }
  .lib-preamble pre code { background: none; padding: 0; color: var(--code); }
  .lib-preamble blockquote {
    border-left: 3px solid var(--border);
    margin: 8px 0;
    padding: 2px 0 2px 12px;
    color: var(--text-dim);
  }

  /* ===================================================================
     Multi-page site additions (documentation/site/).
     Loaded after style.css; reuses its CSS variables and base chrome
     (header, nav, .layout, .badge, .section-heading, .lib-preamble).
     =================================================================== */

  header h1 a { color: inherit; text-decoration: none; }

  /* ---- global search dropdown ---- */
  .search-wrap { margin-left: auto; position: relative; }
  .search-results {
    display: none;
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    width: 440px;
    max-width: 80vw;
    max-height: 65vh;
    overflow-y: auto;
    background: var(--bg2);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
    z-index: 200;
  }
  .search-result {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 8px 12px;
    text-decoration: none;
    border-bottom: 1px solid var(--border);
  }
  .search-result:last-child { border-bottom: none; }
  .search-result:hover { background: var(--bg3); }
  .sr-kind {
    font-size: 0.6rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 2px 6px;
    border-radius: 4px;
    flex-shrink: 0;
  }
  .sr-kind.sr-sym { background: var(--scm-bg);  color: var(--scm);  border: 1px solid var(--scm-border); }
  .sr-kind.sr-lib { background: var(--r7rs-bg); color: var(--r7rs); border: 1px solid var(--r7rs-border); }
  .sr-name {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.85rem;
    color: var(--code);
  }
  .sr-ctx {
    margin-left: auto;
    color: var(--text-dim);
    font-size: 0.75rem;
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    white-space: nowrap;
  }

  /* ---- index landing: library cards ---- */
  .intro {
    color: var(--text-dim);
    font-size: 0.9rem;
    margin-bottom: 28px;
    max-width: 70ch;
  }
  .lib-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 12px;
    margin-bottom: 8px;
  }
  .lib-card {
    display: block;
    padding: 14px 16px;
    background: var(--bg2);
    border: 1px solid var(--border);
    border-left: 3px solid var(--border);
    border-radius: 8px;
    text-decoration: none;
    transition: border-color 0.15s;
  }
  .lib-card:hover { border-color: #3a4560; }
  .lib-card.r7rs { border-left-color: var(--r7rs); }
  .lib-card.scm  { border-left-color: var(--scm);  }
  .lib-card.srfi { border-left-color: var(--srfi); }
  .lib-card .name {
    display: block;
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--heading);
    margin-bottom: 4px;
  }
  .lib-card.r7rs .name { color: var(--r7rs); }
  .lib-card.scm  .name { color: var(--scm);  }
  .lib-card.srfi .name { color: var(--srfi); }
  .lib-card .desc { font-size: 0.8rem; color: var(--text-dim); }

  /* ---- per-library page ---- */
  .backlink {
    display: inline-block;
    margin-bottom: 16px;
    color: var(--text-dim);
    text-decoration: none;
    font-size: 0.85rem;
  }
  .backlink:hover { color: var(--text); }
  .lib-title {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--heading);
    margin-bottom: 4px;
  }
  .lib-title.r7rs { color: var(--r7rs); }
  .lib-title.scm  { color: var(--scm);  }
  .lib-title.srfi { color: var(--srfi); }
  .lib-sub { color: var(--text-dim); font-size: 0.9rem; margin-bottom: 20px; }
  .toolbar { margin: 18px 0 6px; }
  #export-filter {
    width: 100%;
    max-width: 440px;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 7px 12px;
    color: var(--text);
    font-size: 0.85rem;
    outline: none;
  }
  #export-filter:focus { border-color: var(--scm); }
  .export-count { color: var(--text-dim); font-size: 0.75rem; margin-bottom: 8px; }
  .entry { padding: 16px 0; border-top: 1px solid var(--border); }
  .entry-name {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--code);
  }
  .entry-doc {
    margin-top: 8px;
    padding: 12px;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.8rem;
    white-space: pre-wrap;
    color: var(--text);
  }
  .entry .nodoc { margin-top: 6px; color: var(--text-dim); font-style: italic; font-size: 0.85rem; }
  .entry.target { background: rgba(255, 204, 85, 0.05); border-radius: 6px; }
  .entry.target .entry-name { color: #ffcc55; }

  /* ---- per-library page: breadcrumb ---- */
  /* The breadcrumb is a <nav>, so it must shed the sidebar nav chrome. */
  .breadcrumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
    font-size: 0.8rem;
    width: auto;
    height: auto;
    padding: 0;
    background: none;
    border: none;
    position: static;
    overflow: visible;
  }
  .breadcrumb a { color: var(--text-dim); text-decoration: none; }
  .breadcrumb a:hover { color: var(--text); }
  .breadcrumb .sep { color: var(--border); }
  .breadcrumb .current { color: var(--text); }

  /* ---- per-library page: bindings table of contents (left nav) ---- */
  nav.toc a {
    font-family: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
    font-size: 0.78rem;
  }
  nav.toc a:hover { color: var(--scm); border-left-color: var(--scm); }

  /* ---- preamble cross-reference links ---- */
  .lib-preamble a.xref { border-bottom: 1px dotted var(--scm); }
  .lib-preamble a.xref code { color: var(--scm); }
  .lib-preamble a.xref:hover { border-bottom-style: solid; }
  .lib-preamble a.xref:hover code { color: var(--text); }