:root {
  --bg: #f5f5f5;
  --fg: #111111;
  --accent: #2563eb;
  --muted: #666666;
  --radius: 6px;
  --max-width: 720px;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--fg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: var(--max-width);
  margin: 4rem auto;
  padding: 0 1.5rem;
}

header,
footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem;
}

header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.site-title {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

nav a {
  margin-left: 1rem;
  font-size: 0.9rem;
  color: var(--muted);
  text-decoration: none;
}

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

h1,
h2,
h3 {
  line-height: 1.25;
  margin: 0 0 0.75rem;
}

h1 {
  font-size: 2.1rem;
}

h2 {
  font-size: 1.4rem;
  margin-top: 2rem;
}

p {
  margin: 0 0 1rem;
}

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

a:hover {
  text-decoration: underline;
}

.card {
  background: #ffffff;
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.04);
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.9em;
  background: #e5e7eb;
  padding: 0.15em 0.35em;
  border-radius: 4px;
}

pre {
  background: #111827;
  color: #e5e7eb;
  padding: 1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  font-size: 0.9rem;
}

pre code {
  background: transparent;
  padding: 0;
}

footer {
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid #e5e5e5;
  margin-top: 3rem;
}