:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --border: #334155;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
}

header {
  padding: 2rem max(1rem, calc((100vw - 720px) / 2));
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

header .mark {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), #2563eb);
  flex-shrink: 0;
}

header .name {
  font-weight: 600;
  font-size: 1.1rem;
}

nav {
  margin-left: auto;
  display: flex;
  gap: 1.5rem;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
}

nav a:hover, nav a.active {
  color: var(--text);
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 3rem 1rem 5rem;
}

h1 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

h2 {
  font-size: 1.3rem;
  margin-top: 2.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.subtitle {
  color: var(--muted);
  margin-top: 0;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 1.5rem 0;
}

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

a { color: var(--accent); }

ul { padding-left: 1.25rem; }
li { margin-bottom: 0.5rem; }

footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
  padding: 2rem 1rem 3rem;
}