:root {
  --bg: #F7F6F2;
  --surface: #FFFFFF;
  --ink: #16181D;
  --ink-2: #3F434B;
  --muted: #6B6F78;
  --line: #E2E0D9;
  --accent: #4B45D8;
  --accent-soft: #ECEBFC;
  --code-bg: #F0EFEA;
  --radius: 12px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #121317;
    --surface: #1A1C21;
    --ink: #EDEEF0;
    --ink-2: #C9CBD2;
    --muted: #8D919A;
    --line: #2A2D34;
    --accent: #9C98FF;
    --accent-soft: #24233F;
    --code-bg: #20222A;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #121317; --surface: #1A1C21; --ink: #EDEEF0; --ink-2: #C9CBD2; --muted: #8D919A;
  --line: #2A2D34; --accent: #9C98FF; --accent-soft: #24233F; --code-bg: #20222A; color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 17px/1.65 var(--font);
}
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }

/* layout */
.layout { display: grid; grid-template-columns: 280px minmax(0, 1fr); min-height: 100vh; }
.sidebar {
  position: sticky; top: 0; height: 100vh; overflow-y: auto;
  padding: 32px 24px; border-right: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; color: var(--ink); text-decoration: none; font-size: 18px; }
.dot { width: 12px; height: 12px; border-radius: 4px; background: var(--accent); }
.sidebar nav { margin-top: 32px; }
.sidebar ul, .menu ul { list-style: none; margin: 0; padding: 0; }
.sidebar li a, .menu li a {
  display: block; padding: 8px 12px; border-radius: 8px;
  color: var(--ink-2); text-decoration: none; font-size: 15px;
}
.sidebar li a:hover, .menu li a:hover { background: var(--accent-soft); color: var(--ink); }
.sidebar li a.active, .menu li a.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.side-note { margin-top: 32px; color: var(--muted); font-size: 13px; line-height: 1.5; }

main { padding: 56px 48px 40px; }
.content, .pager, footer { max-width: 760px; }

.topbar { display: none; }

/* typography */
.content h1 { font-size: 40px; line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 16px; }
.content h2 { font-size: 26px; line-height: 1.25; margin: 48px 0 12px; letter-spacing: -0.01em; }
.content h3 { font-size: 19px; margin: 32px 0 8px; }
.content p, .content ul, .content ol { margin: 0 0 16px; }
.content li { margin: 4px 0; }
.content li > ul, .content li > ol { margin: 4px 0 0; }
.lead { font-size: 20px; color: var(--ink-2); }
.content hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }
.content strong { font-weight: 700; }

code { font-family: var(--mono); font-size: 0.88em; background: var(--code-bg); padding: 2px 6px; border-radius: 6px; }
pre {
  background: var(--code-bg); border-radius: var(--radius); padding: 16px 20px;
  overflow-x: auto; font-size: 14px; line-height: 1.55; margin: 0 0 20px;
}
pre code { background: none; padding: 0; font-size: inherit; }

blockquote {
  margin: 0 0 20px; padding: 14px 20px; border-left: 4px solid var(--accent);
  background: var(--accent-soft); border-radius: 0 var(--radius) var(--radius) 0; color: var(--ink);
}
blockquote p:last-child { margin-bottom: 0; }

.table-wrap, .content table { width: 100%; }
.content table {
  border-collapse: collapse; margin: 0 0 24px; font-size: 15px;
  display: block; overflow-x: auto;
}
.content th, .content td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.content th { font-weight: 700; color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: 0.04em; }

/* cards */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin: 24px 0 32px; }
.card {
  display: block; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; color: var(--ink); text-decoration: none; transition: border-color .15s, transform .15s;
}
a.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card .kicker { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--accent); }
.card h3 { margin: 6px 0 6px; font-size: 19px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.5; }

.path { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 12px 0 24px; }
.path span { background: var(--surface); border: 1px solid var(--line); border-radius: 999px; padding: 4px 12px; font-size: 14px; }
.path i { color: var(--muted); font-style: normal; }

.download {
  display: flex; gap: 16px; align-items: center; background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 16px 20px; margin: 0 0 12px; text-decoration: none; color: var(--ink);
}
.download:hover { border-color: var(--accent); }
.download b { display: block; }
.download small { color: var(--muted); }
.download .ext { flex: none; width: 48px; height: 48px; border-radius: 10px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-weight: 800; font-size: 12px; }

/* pager & footer */
.pager { display: flex; gap: 16px; margin-top: 56px; }
.pager a {
  flex: 1; border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 18px;
  text-decoration: none; color: var(--ink); font-weight: 600; background: var(--surface);
}
.pager a:hover { border-color: var(--accent); }
.pager span { display: block; font-size: 12px; color: var(--muted); font-weight: 400; text-transform: uppercase; letter-spacing: .05em; }
.pager .next { text-align: right; }
footer { margin-top: 48px; color: var(--muted); font-size: 13px; }

/* mobile */
@media (max-width: 900px) {
  .layout { display: block; }
  .sidebar { display: none; }
  .topbar {
    display: flex; justify-content: space-between; align-items: center;
    position: sticky; top: 0; z-index: 10; padding: 12px 16px;
    background: var(--bg); border-bottom: 1px solid var(--line);
  }
  .menu summary { list-style: none; cursor: pointer; padding: 6px 12px; border: 1px solid var(--line); border-radius: 8px; font-size: 14px; }
  .menu summary::-webkit-details-marker { display: none; }
  .menu[open] ul {
    position: absolute; left: 0; right: 0; top: 100%; background: var(--bg);
    border-bottom: 1px solid var(--line); padding: 8px 16px 16px;
  }
  main { padding: 32px 16px 32px; }
  .content h1 { font-size: 30px; }
  .content h2 { font-size: 22px; margin-top: 36px; }
  body { font-size: 16px; }
  .pager { flex-direction: column; }
  .pager .next { text-align: left; }
}

/* glossary */
.content dl { margin: 0 0 24px; }
.content dt { font-weight: 700; margin-top: 18px; }
.content dd { margin: 4px 0 0; color: var(--ink-2); padding-left: 16px; border-left: 2px solid var(--line); }