:root {
  --bg: #f7f6f2;
  --surface: #ffffff;
  --text: #1c1d1f;
  --muted: #5d6066;
  --line: #e3e1da;
  --accent: #1f4e79;
  --accent-soft: #e6eef6;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121315;
    --surface: #1b1d20;
    --text: #ecedee;
    --muted: #a3a7ad;
    --line: #2c2f33;
    --accent: #7fb0e0;
    --accent-soft: #1d2a37;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
.wrap { max-width: 880px; margin: 0 auto; padding: 0 16px; }

header.top {
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
header.top .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; min-height: 64px; flex-wrap: wrap;
}
.brand { font-weight: 700; letter-spacing: -0.01em; text-decoration: none; color: var(--text); font-size: 18px; }
.brand span { color: var(--accent); }
nav a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 15px; }
nav a:first-child { margin-left: 0; }
nav a:hover { color: var(--text); }

.hero { padding: 64px 0 40px; }
.hero h1 { font-size: clamp(30px, 5vw, 44px); line-height: 1.15; margin: 0 0 16px; letter-spacing: -0.02em; }
.hero p { font-size: 18px; color: var(--muted); max-width: 620px; margin: 0; }

section { padding: 32px 0; }
section h2 { font-size: 22px; margin: 0 0 20px; letter-spacing: -0.01em; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 16px; }
.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 12px; padding: 20px;
}
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.tag {
  display: inline-block; font-size: 12px; font-weight: 600; letter-spacing: 0.04em;
  text-transform: uppercase; color: var(--accent); background: var(--accent-soft);
  padding: 2px 8px; border-radius: 999px; margin-bottom: 10px;
}

dl.data { display: grid; grid-template-columns: max-content 1fr; gap: 6px 20px; margin: 0; }
dl.data dt { color: var(--muted); }
dl.data dd { margin: 0; }
@media (max-width: 520px) {
  dl.data { grid-template-columns: 1fr; }
  dl.data dd { margin-bottom: 10px; }
}

.doc { padding: 48px 0; }
.doc h1 { font-size: 32px; margin: 0 0 6px; letter-spacing: -0.02em; }
.doc .updated { color: var(--muted); margin: 0 0 32px; }
.doc h2 { font-size: 20px; margin: 32px 0 10px; }
.doc p, .doc li { color: var(--text); }
.doc ul { padding-left: 22px; }

footer {
  border-top: 1px solid var(--line); margin-top: 48px; padding: 24px 0 40px;
  color: var(--muted); font-size: 14px;
}
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
footer a { color: var(--muted); margin-right: 14px; }