:root {
  --bg: #f7f9fc;
  --surface: #ffffff;
  --text: #000e22;
  --muted: #4a5d75;
  --border: #d7e2ee;
  --link: #1e64c6;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000e22;
    --surface: #071c38;
    --text: #f7faff;
    --muted: #abbdd3;
    --border: #3f78ae;
    --link: #8ac4ef;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
    'Noto Sans', sans-serif;
}

main {
  max-width: 680px;
  margin: 0 auto;
  padding: 40px 18px 64px;
}

header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 28px;
}

header img {
  width: 56px;
  height: 56px;
  border-radius: 12px;
}

header p {
  margin: 0;
  color: var(--muted);
}

h1 {
  margin: 0;
  font-size: 28px;
  line-height: 1.2;
}

h2 {
  margin: 32px 0 8px;
  font-size: 20px;
}

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

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px 20px;
  margin: 16px 0;
}

.muted {
  color: var(--muted);
}

nav {
  margin-top: 40px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 20px;
  font-size: 15px;
}