:root {
  color-scheme: light;
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #1f2937;
  --muted: #5f6b7a;
  --border: #d8dde5;
  --accent: #2457c5;
  --accent-soft: #edf2ff;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

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

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

a:hover {
  text-decoration: underline;
}

.site {
  max-width: 920px;
  margin: 0 auto;
  padding: 40px 20px 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
}

.brand {
  font-size: 15px;
  font-weight: 600;
  color: var(--muted);
}

.nav {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  font-size: 14px;
}

.hero,
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.hero {
  padding: 30px 32px;
  margin-bottom: 18px;
}

.hero h1 {
  margin: 0 0 10px;
  font-size: 30px;
  line-height: 1.25;
  letter-spacing: 0;
}

.hero p {
  margin: 0;
  color: var(--muted);
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.card {
  padding: 22px 24px;
}

.card h2,
.doc h2 {
  margin: 0 0 10px;
  font-size: 20px;
  line-height: 1.35;
}

.card p {
  margin: 0 0 16px;
  color: var(--muted);
}

.doc {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 32px;
}

.doc h1 {
  margin: 0 0 8px;
  font-size: 30px;
  line-height: 1.25;
}

.doc h2 {
  margin-top: 30px;
}

.doc p,
.doc li {
  color: var(--text);
}

.doc .muted {
  color: var(--muted);
}

.notice {
  background: var(--accent-soft);
  border: 1px solid #ccd9ff;
  border-radius: 8px;
  padding: 14px 16px;
  margin: 20px 0;
}

.listing-block {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  margin: 14px 0;
  background: #fbfcfe;
}

.listing-block h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.listing-block pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  font: inherit;
  color: var(--text);
}

.footer {
  margin-top: 22px;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 720px) {
  .site {
    padding: 24px 14px 40px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .hero,
  .doc,
  .card {
    padding: 22px 18px;
  }

  .hero h1,
  .doc h1 {
    font-size: 24px;
  }
}