:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --accent: #2563eb;
  --border: #e5e7eb;
  --card: #f9fafb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0b0f;
    --fg: #e5e7eb;
    --muted: #9ca3af;
    --accent: #60a5fa;
    --border: #1f2937;
    --card: #111827;
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

header {
  border-bottom: 1px solid var(--border);
  background: var(--card);
}

header nav {
  max-width: 760px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  gap: 20px;
  font-size: 14px;
}

header nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
}

header nav a.active {
  color: var(--fg);
}

header nav a:hover {
  color: var(--accent);
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 40px 24px 60px;
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 8px;
}

h2 {
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 36px 0 12px;
  padding-top: 8px;
}

h3 {
  font-size: 1.08rem;
  font-weight: 600;
  margin: 24px 0 8px;
}

p, ul {
  margin: 10px 0;
}

ul {
  padding-left: 22px;
}

li {
  margin: 4px 0;
}

.meta {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

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

a:hover {
  text-decoration: underline;
}

strong {
  font-weight: 600;
  color: var(--fg);
}

footer {
  border-top: 1px solid var(--border);
  padding: 24px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}

footer a {
  color: var(--muted);
}

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