/* AB Test documentation — brand theme (light + dark) */
:root {
  --brand: #4C5BD4;
  --brand-strong: #3b45b0;
  --brand-tint: #eef0fb;
  --bg: #ffffff;
  --bg-soft: #f7f8fb;
  --bg-sidebar: #ffffff;
  --text: #1c1e26;
  --text-muted: #5b6070;
  --text-faint: #8a8f9e;
  --border: #ececf1;
  --border-strong: #dcdde6;
  --code-bg: #f5f6f8;
  --code-text: #35384a;
  --sel: #dfe3fb;
  --topbar-h: 60px;
  --sidebar-w: 268px;
  --toc-w: 220px;
  --content-max: 760px;
  --radius: 10px;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
:root[data-theme="dark"] {
  --brand: #7c8bf0;
  --brand-strong: #93a0f4;
  --brand-tint: #23273a;
  --bg: #0f1117;
  --bg-soft: #151824;
  --bg-sidebar: #0f1117;
  --text: #e6e8ef;
  --text-muted: #9aa0b2;
  --text-faint: #6c7284;
  --border: #23263300;
  --border: #232633;
  --border-strong: #2e3242;
  --code-bg: #171a24;
  --code-text: #c8ccda;
  --sel: #2b3160;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 16px); }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
::selection { background: var(--sel); }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 40;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 20px;
  padding: 0 24px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(8px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 600; color: var(--text); white-space: nowrap; }
.brand img { width: 28px; height: 28px; display: block; }
.brand .sub { color: var(--text-faint); font-weight: 500; }
.tabs { display: flex; gap: 4px; margin-left: 8px; }
.tabs a {
  padding: 7px 14px; border-radius: 8px; font-size: 14.5px; font-weight: 500;
  color: var(--text-muted);
}
.tabs a:hover { background: var(--bg-soft); text-decoration: none; color: var(--text); }
.tabs a.active { color: var(--brand); background: var(--brand-tint); }
.topbar .spacer { flex: 1; }
.search-btn {
  display: flex; align-items: center; gap: 8px; min-width: 200px;
  padding: 7px 12px; border: 1px solid var(--border-strong); border-radius: 9px;
  background: var(--bg-soft); color: var(--text-faint); font-size: 14px; cursor: text;
}
.search-btn kbd {
  margin-left: auto; font-family: var(--sans); font-size: 11px; padding: 2px 6px;
  border: 1px solid var(--border-strong); border-radius: 5px; color: var(--text-faint);
}
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border: 1px solid var(--border-strong); border-radius: 9px;
  background: transparent; color: var(--text-muted); cursor: pointer;
}
.icon-btn:hover { background: var(--bg-soft); color: var(--text); }
.ghost-link {
  padding: 7px 14px; border-radius: 9px; font-size: 14px; font-weight: 500;
  border: 1px solid var(--border-strong); color: var(--text);
}
.ghost-link:hover { background: var(--bg-soft); text-decoration: none; }
.menu-toggle { display: none; }

/* ---------- Layout ---------- */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr) var(--toc-w);
  max-width: 1440px; margin: 0 auto;
}
.sidebar {
  grid-column: 1;
  position: sticky; top: var(--topbar-h); align-self: start;
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto;
  padding: 28px 18px 60px 24px;
  border-right: 1px solid var(--border);
  background: var(--bg-sidebar);
}
.sidebar .group { margin-bottom: 24px; }
.sidebar .group h4 {
  margin: 0 0 8px; padding: 0 10px;
  font-size: 12px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase;
  color: var(--text-faint);
}
.sidebar a {
  display: block; padding: 6px 10px; border-radius: 7px;
  font-size: 14.5px; color: var(--text-muted); font-weight: 450;
}
.sidebar a:hover { background: var(--bg-soft); color: var(--text); text-decoration: none; }
.sidebar a.active { color: var(--brand); background: var(--brand-tint); font-weight: 500; }

.content { grid-column: 2; min-width: 0; padding: 40px 48px 80px; }
.doc-content { max-width: var(--content-max); }

.toc {
  grid-column: 3;
  position: sticky; top: var(--topbar-h); align-self: start;
  height: calc(100vh - var(--topbar-h)); overflow-y: auto;
  padding: 40px 24px; font-size: 13.5px;
}
.toc h5 { margin: 0 0 10px; font-size: 12px; text-transform: uppercase; letter-spacing: .04em; color: var(--text-faint); font-weight: 600; }
.toc a { display: block; padding: 4px 0 4px 12px; color: var(--text-muted); border-left: 2px solid var(--border); }
.toc a:hover { color: var(--text); text-decoration: none; }
.toc a.active { color: var(--brand); border-left-color: var(--brand); }
.toc a.lvl3 { padding-left: 24px; font-size: 13px; }

/* ---------- Content typography ---------- */
.doc-content h1 { font-size: 34px; line-height: 1.2; font-weight: 680; margin: 0 0 8px; letter-spacing: -0.01em; }
.doc-content .lead { font-size: 18px; color: var(--text-muted); margin: 0 0 32px; }
.doc-content h2 { font-size: 23px; font-weight: 600; margin: 44px 0 14px; padding-top: 8px; letter-spacing: -0.01em; }
.doc-content h3 { font-size: 18px; font-weight: 600; margin: 30px 0 10px; }
.doc-content p { margin: 14px 0; }
.doc-content ul, .doc-content ol { margin: 14px 0; padding-left: 24px; }
.doc-content li { margin: 6px 0; }
.doc-content hr { border: none; border-top: 1px solid var(--border); margin: 40px 0; }
.doc-content code {
  font-family: var(--mono); font-size: 0.86em; background: var(--code-bg); color: var(--code-text);
  padding: 2px 6px; border-radius: 6px; border: 1px solid var(--border);
}
.doc-content pre {
  background: var(--code-bg); border: 1px solid var(--border); border-radius: 12px;
  padding: 16px 18px; overflow-x: auto; margin: 18px 0; font-size: 13.5px; line-height: 1.6;
}
.doc-content pre code { background: none; border: none; padding: 0; color: var(--code-text); font-size: inherit; }
.doc-content table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14.5px; display: block; overflow-x: auto; }
.doc-content th, .doc-content td { text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--border); }
.doc-content th { font-weight: 600; color: var(--text); background: var(--bg-soft); }
.doc-content blockquote { margin: 18px 0; padding: 2px 18px; border-left: 3px solid var(--border-strong); color: var(--text-muted); }

/* callouts */
.callout { display: flex; gap: 12px; padding: 14px 16px; border-radius: 12px; margin: 20px 0; font-size: 14.5px; border: 1px solid var(--border); background: var(--bg-soft); }
.callout .ci { flex: none; width: 20px; height: 20px; margin-top: 2px; }
.callout p { margin: 0; }
.callout.note { border-color: #cdd6f6; background: #eef1fc; color: #2e3572; }
.callout.tip { border-color: #bfe6d5; background: #e7f6ef; color: #10553f; }
.callout.warn { border-color: #f2d9a8; background: #fbf1dd; color: #7a5410; }
:root[data-theme="dark"] .callout.note { border-color: #303a6b; background: #1a1e33; color: #b9c2f0; }
:root[data-theme="dark"] .callout.tip { border-color: #22503f; background: #12241d; color: #8fe0bf; }
:root[data-theme="dark"] .callout.warn { border-color: #4d3c17; background: #241d10; color: #e8c583; }

/* landing cards */
.hero { max-width: var(--content-max); margin-bottom: 8px; }
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; margin: 24px 0; max-width: var(--content-max); }
.card { display: block; padding: 18px; border: 1px solid var(--border); border-radius: 14px; background: var(--bg); transition: border-color .15s, transform .15s; }
.card:hover { border-color: var(--brand); text-decoration: none; transform: translateY(-2px); }
.card .ci { width: 22px; height: 22px; color: var(--brand); margin-bottom: 10px; }
.card h3 { margin: 0 0 4px; font-size: 15.5px; font-weight: 600; color: var(--text); }
.card p { margin: 0; font-size: 13.5px; color: var(--text-muted); line-height: 1.55; }

/* prev/next */
.page-nav { display: flex; justify-content: space-between; gap: 16px; margin-top: 56px; padding-top: 24px; border-top: 1px solid var(--border); max-width: var(--content-max); }
.page-nav a { flex: 1; padding: 14px 18px; border: 1px solid var(--border); border-radius: 12px; }
.page-nav a:hover { border-color: var(--brand); text-decoration: none; }
.page-nav .dir { font-size: 12px; color: var(--text-faint); }
.page-nav .ttl { font-size: 15px; font-weight: 500; color: var(--text); }
.page-nav .next { text-align: right; }

/* pill / badges */
.pill { display: inline-block; padding: 2px 9px; font-size: 12px; font-weight: 600; border-radius: 20px; background: var(--brand-tint); color: var(--brand-strong); vertical-align: middle; }
.method { font-family: var(--mono); font-weight: 700; }

/* search modal */
.search-overlay { position: fixed; inset: 0; z-index: 100; background: rgba(10,12,20,.45); display: none; align-items: flex-start; justify-content: center; padding-top: 12vh; }
.search-overlay.open { display: flex; }
.search-box { width: min(560px, 92vw); background: var(--bg); border: 1px solid var(--border-strong); border-radius: 14px; overflow: hidden; box-shadow: 0 20px 60px rgba(0,0,0,.3); }
.search-box input { width: 100%; border: none; outline: none; padding: 18px 20px; font-size: 16px; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border); }
.search-results { max-height: 50vh; overflow-y: auto; }
.search-results a { display: block; padding: 12px 20px; color: var(--text); border-bottom: 1px solid var(--border); }
.search-results a:hover, .search-results a.sel { background: var(--brand-tint); text-decoration: none; }
.search-results .r-tab { font-size: 12px; color: var(--text-faint); }
.search-results .empty { padding: 24px 20px; color: var(--text-faint); font-size: 14px; }

/* ---------- Responsive ---------- */
@media (max-width: 1100px) { .toc { display: none; } .layout { grid-template-columns: var(--sidebar-w) minmax(0,1fr); } }
@media (max-width: 820px) {
  .layout { grid-template-columns: minmax(0, 1fr); }
  .menu-toggle { display: inline-flex; }
  .tabs { display: none; }
  .search-btn { min-width: 0; width: 40px; padding: 7px; }
  .search-btn .lbl, .search-btn kbd { display: none; }
  .ghost-link { display: none; }
  .sidebar {
    position: fixed; top: var(--topbar-h); left: 0; width: 82vw; max-width: 320px; z-index: 45;
    height: calc(100vh - var(--topbar-h)); transform: translateX(-100%); transition: transform .2s;
    box-shadow: 0 10px 40px rgba(0,0,0,.2);
  }
  body.nav-open .sidebar { transform: translateX(0); }
  body.nav-open::after { content:""; position: fixed; inset: var(--topbar-h) 0 0 0; background: rgba(0,0,0,.4); z-index: 44; }
  .content { padding: 28px 20px 64px; }
  .sidebar .m-tabs { display: block; margin-bottom: 20px; }
}
.sidebar .m-tabs { display: none; }
.sidebar .m-tabs a { font-weight: 500; }