:root {
  --bg: #ffffff;
  --surface: #f5f5f7;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --border: #d2d2d7;
  --accent: #007aff;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --surface: #1c1c1e;
    --text: #f5f5f7;
    --text-secondary: #98989d;
    --border: #38383a;
    --accent: #0a84ff;
  }
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI",
    Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

a:hover {
  text-decoration: underline;
}

.site-header,
main,
.site-footer {
  max-width: 720px;
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

.brand {
  font-weight: 700;
  font-size: 19px;
  color: var(--text);
}

.site-header nav {
  display: flex;
  gap: 18px;
  font-size: 15px;
}

main {
  padding-top: 32px;
  padding-bottom: 48px;
}

h1 {
  font-size: 34px;
  line-height: 1.15;
  margin: 0 0 8px;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 22px;
  margin: 36px 0 8px;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 17px;
  margin: 20px 0 4px;
}

p,
ul {
  margin: 0 0 14px;
}

ul {
  padding-left: 22px;
}

li {
  margin-bottom: 6px;
}

.meta {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 28px;
}

.lead {
  font-size: 20px;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.card {
  background: var(--surface);
  border-radius: 14px;
  padding: 18px 20px;
  margin: 0 0 14px;
}

.card p:last-child {
  margin-bottom: 0;
}

.site-footer {
  padding-top: 20px;
  padding-bottom: 32px;
  border-top: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 14px;
}

.site-footer a {
  margin-right: 16px;
}

@media (max-width: 480px) {
  h1 {
    font-size: 28px;
  }
  .site-header nav {
    gap: 12px;
  }
}