:root {
  --bg: #f4f6f9;
  --panel: #ffffff;
  --ink: #111827;
  --muted: #5b6472;
  --line: #e2e6ee;
  --accent: #2457d6;
  --accent-ink: #1a43ad;
  --accent-soft: #eef3ff;
  --warn: #9a4b00;
  --warn-bg: #fff6e9;
  --warn-line: #f2c98c;
  --code-bg: #f1f3f7;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 10px 28px rgba(16, 24, 40, .05);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --panel: #141a22;
    --ink: #e7ecf3;
    --muted: #9aa6b6;
    --line: #26303d;
    --accent: #7aa2ff;
    --accent-ink: #9dbaff;
    --accent-soft: #17233c;
    --warn: #ffc078;
    --warn-bg: #2a1f10;
    --warn-line: #5c431f;
    --code-bg: #1b2330;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 10px 28px rgba(0, 0, 0, .25);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.78 -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-ink); }

.skip {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 50;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 14px;
}
.skip:focus { top: 12px; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 24px;
  padding: 14px clamp(16px, 4vw, 64px);
  background: color-mix(in srgb, var(--panel) 88%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.brand { display: flex; align-items: center; gap: 12px; min-width: 0; }

.logo {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 11px;
  background: linear-gradient(135deg, #2457d6, #6d8dff);
  color: #fff;
  font-weight: 700;
  font-size: 18px;
  letter-spacing: .02em;
  flex: none;
}

.brand strong { display: block; font-size: 16px; line-height: 1.25; }
.brand small { display: block; color: var(--muted); font-size: 12px; line-height: 1.4; }

.topnav { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }

.topnav a {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 9px;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  white-space: nowrap;
}
.topnav a:hover { background: var(--accent-soft); color: var(--accent-ink); }
.topnav a[aria-current="page"] { background: var(--accent-soft); color: var(--accent-ink); }
.topnav a.lang { border: 1px solid var(--line); color: var(--ink); }

.shell {
  display: grid;
  grid-template-columns: minmax(220px, 280px) minmax(0, 1fr);
  gap: clamp(20px, 3vw, 56px);
  align-items: start;
  width: 100%;
  padding: clamp(18px, 3.2vw, 44px) clamp(16px, 4vw, 64px) 72px;
}

.toc {
  position: sticky;
  top: 84px;
  padding: 18px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  max-height: calc(100vh - 108px);
  overflow: auto;
}

.toc p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.toc ol { margin: 0; padding-left: 18px; }
.toc li { margin: 3px 0; }
.toc a {
  color: var(--muted);
  text-decoration: none;
  font-size: 13.5px;
  line-height: 1.5;
  display: inline-block;
  padding: 2px 0;
}
.toc a:hover { color: var(--accent-ink); }

.doc {
  min-width: 0;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: clamp(20px, 3.2vw, 52px);
}

.doc p,
.doc li { max-width: 92ch; }

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent-ink);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1.2;
  letter-spacing: -.02em;
}

h2 {
  margin: 44px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
  font-size: clamp(20px, 2.2vw, 25px);
  line-height: 1.35;
  letter-spacing: -.01em;
  scroll-margin-top: 90px;
}

h3 {
  margin: 28px 0 8px;
  font-size: 17.5px;
  line-height: 1.45;
  scroll-margin-top: 90px;
}

.meta { margin: 0 0 4px; color: var(--muted); font-size: 14px; }

.lead {
  margin: 20px 0 0;
  padding: 16px 18px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 10px 10px 0;
  max-width: 92ch;
}

.callout {
  margin: 24px 0 8px;
  padding: 18px 20px;
  border: 1px solid var(--warn-line);
  border-radius: 12px;
  background: var(--warn-bg);
  max-width: 96ch;
}
.callout strong { color: var(--warn); }
.callout p:first-child { margin-top: 0; }
.callout p:last-child { margin-bottom: 0; }

ul, ol { padding-left: 22px; }
li { margin: 5px 0; }

code {
  padding: 1px 5px;
  border-radius: 5px;
  background: var(--code-bg);
  font: .9em/1.6 ui-monospace, Consolas, "SFMono-Regular", monospace;
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 16px 0;
  border: 1px solid var(--line);
  border-radius: 10px;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
  font-size: 14.5px;
}

td code { overflow-wrap: anywhere; }

th, td {
  padding: 10px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}
tbody tr:last-child td { border-bottom: 0; }
th { background: var(--code-bg); font-weight: 650; white-space: nowrap; }

hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }

footer {
  padding: 26px clamp(16px, 4vw, 64px) 48px;
  color: var(--muted);
  font-size: 13px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  justify-content: space-between;
  border-top: 1px solid var(--line);
}
footer nav { display: flex; flex-wrap: wrap; gap: 8px 18px; }
footer a { color: var(--muted); }

.toc-mobile { display: none; }

@media (max-width: 960px) {
  .shell { grid-template-columns: 1fr; }
  .toc { display: none; }
  .toc-mobile {
    display: block;
    margin: 20px 0 4px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--bg);
    padding: 10px 14px;
  }
  .toc-mobile summary { cursor: pointer; font-weight: 650; }
  .toc-mobile ol { margin: 8px 0 0; }
  .doc p, .doc li { max-width: none; }
  .topbar { position: static; }
}

@media (max-width: 720px) {
  .table-wrap { border: 0; overflow: visible; }
  table, tbody, tr, td { display: block; width: 100%; min-width: 0; }
  thead { display: none; }
  tbody tr {
    margin: 0 0 12px;
    padding: 6px 0;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--bg);
  }
  tbody tr:last-child { margin-bottom: 0; }
  td {
    display: grid;
    grid-template-columns: minmax(84px, 32%) minmax(0, 1fr);
    gap: 12px;
    padding: 7px 14px;
    border: 0;
    font-size: 14px;
  }
  td::before {
    content: attr(data-label);
    color: var(--muted);
    font-weight: 650;
    font-size: 13px;
    line-height: 1.6;
  }
  td:empty { display: none; }
}

@media print {
  .topbar, .toc, .toc-mobile, footer { display: none; }
  body { background: #fff; }
  .shell { display: block; padding: 0; }
  .doc { border: 0; box-shadow: none; padding: 0; }
  h2 { break-after: avoid; }
  a { color: inherit; text-decoration: none; }
}