:root {
  color-scheme: light dark;
  --background: #f7f7f9;
  --surface: #ffffff;
  --text: #202124;
  --secondary: #5f6368;
  --accent: #315cce;
  --border: #d9dce3;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #111318;
    --surface: #1a1d24;
    --text: #f2f3f5;
    --secondary: #b2b7c2;
    --accent: #91adff;
    --border: #343945;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-size: 16px;
  line-height: 1.75;
}

header, main, footer {
  width: min(100% - 32px, 760px);
  margin-inline: auto;
}

header { padding: 28px 0 12px; }
main {
  margin-block: 16px 40px;
  padding: clamp(20px, 5vw, 40px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
}
footer {
  padding-bottom: 40px;
  color: var(--secondary);
  font-size: 0.9rem;
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

h1, h2, h3 { line-height: 1.35; }
h1 { margin-top: 0; font-size: clamp(1.7rem, 7vw, 2.4rem); }
h2 { margin-top: 2.2rem; font-size: 1.35rem; }
h3 { margin-top: 1.5rem; font-size: 1.1rem; }
a { color: var(--accent); text-underline-offset: 0.18em; }
p, li { overflow-wrap: anywhere; }
.lead { color: var(--secondary); font-size: 1.05rem; }
.notice {
  padding: 14px 16px;
  border-left: 4px solid var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
}
.updated { color: var(--secondary); font-size: 0.9rem; }
dt { margin-top: 1rem; font-weight: 700; }
dd { margin-left: 0; }

@media (max-width: 420px) {
  header, main, footer { width: min(100% - 20px, 760px); }
  main { border-radius: 12px; }
}