:root {
  --bg: #f5f6fa;
  --surface: #ffffff;
  --text: #1c1c1e;
  --muted: #6b6b73;
  --border: #e3e4ea;
  --accent: #2563eb;
  --accent-soft: #e8efff;
  --radius: 16px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --surface: #181b21;
    --text: #f2f2f5;
    --muted: #a0a3ad;
    --border: #2a2e37;
    --accent: #5b8cff;
    --accent-soft: #1d2740;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

header.site {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
header.site .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 60px;
  flex-wrap: wrap;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--text);
}
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
nav.links { display: flex; gap: 18px; font-size: 15px; }

.hero { text-align: center; padding: 56px 0 32px; }
.hero img {
  width: 112px;
  height: 112px;
  border-radius: 26px;
  box-shadow: 0 10px 30px rgba(37, 99, 235, 0.25);
}
.hero h1 { font-size: 34px; margin: 20px 0 8px; line-height: 1.25; }
.hero p { color: var(--muted); margin: 0 auto; max-width: 520px; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin: 24px 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

section { margin: 40px 0; }
section > h2 { font-size: 22px; margin: 0 0 12px; }

details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 18px;
  margin-bottom: 10px;
}
details summary { cursor: pointer; font-weight: 600; }
details p, details ol, details ul { color: var(--muted); margin: 10px 0 0; }

.notice {
  background: var(--accent-soft);
  border-radius: 12px;
  padding: 14px 18px;
  font-size: 15px;
}

article.doc {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  margin: 32px 0;
}
article.doc h1 { font-size: 28px; margin: 0 0 4px; line-height: 1.3; }
article.doc h2 { font-size: 19px; margin: 28px 0 8px; }
article.doc .meta { color: var(--muted); font-size: 14px; margin: 0 0 20px; }
article.doc ul { padding-left: 22px; }
article.doc li { margin: 4px 0; }

.lang-switch { font-size: 14px; color: var(--muted); }

footer.site {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
  padding: 24px 0 40px;
  margin-top: 48px;
}
footer.site .wrap { display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: space-between; }

@media (max-width: 520px) {
  .hero h1 { font-size: 28px; }
  article.doc { padding: 22px 16px; }
  nav.links { gap: 14px; }
}