:root {
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #1c1c1e;
  --muted: #6b7280;
  --accent: #4a8cff;
  --border: #e6e8eb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --card: #1a1d23;
    --text: #f2f3f5;
    --muted: #9aa0ab;
    --accent: #6ea3ff;
    --border: #2a2e36;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0 20px 64px;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

.container {
  max-width: 720px;
  margin: 0 auto;
}

header {
  padding: 40px 0 8px;
}

header .brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--accent);
}

h1 {
  font-size: 1.9rem;
  margin: 18px 0 4px;
  letter-spacing: -0.02em;
}

.updated {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 28px;
}

h2 {
  font-size: 1.2rem;
  margin: 32px 0 10px;
  letter-spacing: -0.01em;
}

p, li { color: var(--text); }
li { margin: 6px 0; }

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

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px 22px;
  margin: 16px 0;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0;
}

.nav-links a {
  display: inline-block;
  padding: 12px 18px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  font-weight: 600;
}

footer {
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
}

.note {
  background: rgba(74, 140, 255, 0.08);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 12px 16px;
  margin: 16px 0;
  font-size: 0.95rem;
}