:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --text: #16181d;
  --muted: #5b616e;
  --line: #e3e3df;
  --accent: #1f5f4a;
  --accent-soft: #e6f0ec;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111317;
    --surface: #181b21;
    --text: #e9eaec;
    --muted: #a0a6b1;
    --line: #2a2e36;
    --accent: #6fc3a2;
    --accent-soft: #1c2b26;
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
.wrap { max-width: 880px; margin: 0 auto; padding: 0 16px; }
header { border-bottom: 1px solid var(--line); background: var(--surface); }
header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { font-weight: 700; letter-spacing: 0.2px; color: var(--text); text-decoration: none; font-size: 18px; }
.brand span { color: var(--accent); }
nav a { color: var(--muted); text-decoration: none; margin-left: 20px; font-size: 15px; }
nav a:hover { color: var(--text); }
.hero { padding: 72px 0 48px; }
.hero h1 { font-size: clamp(30px, 5vw, 44px); line-height: 1.15; margin: 0 0 16px; letter-spacing: -0.5px; }
.hero p { color: var(--muted); font-size: 18px; max-width: 640px; margin: 0; }
.tag { display: inline-block; background: var(--accent-soft); color: var(--accent); border-radius: 999px; padding: 4px 12px; font-size: 13px; font-weight: 600; margin-bottom: 20px; }
section { padding: 32px 0; }
h2 { font-size: 22px; margin: 0 0 16px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 20px; }
.card h3 { margin: 0 0 8px; font-size: 16px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.doc h1 { font-size: 30px; margin: 48px 0 8px; }
.doc h2 { margin-top: 32px; }
.doc p, .doc li { color: var(--text); }
.doc .muted { color: var(--muted); }
a { color: var(--accent); }
footer { border-top: 1px solid var(--line); margin-top: 48px; padding: 24px 0 40px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; }