:root {
  --bg: #f5f6fa;
  --text: #16203a;
  --muted: #5d6881;
  --accent: #3563e9;
  --accent-text: #ffffff;
  --code-bg: #e8ecf5;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1628;
    --text: #e8ecf5;
    --muted: #9aa5bf;
    --accent: #5b82f0;
    --code-bg: #1d2740;
    color-scheme: dark;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 64px 16px;
}

h1 {
  margin: 0;
  font-size: 40px;
  line-height: 1.1;
}

h2 {
  margin: 48px 0 12px;
  font-size: 22px;
}

.lead {
  margin: 8px 0 28px;
  color: var(--muted);
  font-size: 18px;
}

.button {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 600;
  text-decoration: none;
}

.button:hover,
.button:focus-visible {
  filter: brightness(1.08);
}

.meta {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 14px;
}

ol {
  margin: 0;
  padding-left: 22px;
}

li + li {
  margin-top: 10px;
}

code {
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--code-bg);
  font-size: 14px;
}