:root {
  color-scheme: light dark;
  --bg: #f7f7f8;
  --card: #ffffff;
  --text: #1c1c1e;
  --muted: #666a73;
  --line: #e5e5ea;
  --accent: #0a84ff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111113;
    --card: #1c1c1e;
    --text: #f5f5f7;
    --muted: #a1a1aa;
    --line: #33333a;
    --accent: #64aaff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
}
a { color: var(--accent); }
.container {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
}
.hero {
  padding: 64px 0 28px;
}
.hero h1 {
  font-size: clamp(2rem, 6vw, 4rem);
  line-height: 1.15;
  margin: 0 0 12px;
  letter-spacing: -0.04em;
}
.hero p {
  margin: 0;
  color: var(--muted);
  font-size: 1.08rem;
}
.nav {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  padding: 18px 0 24px;
}
.nav a {
  text-decoration: none;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--text);
  border-radius: 999px;
  padding: 8px 14px;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 24px;
  margin: 18px 0;
  box-shadow: 0 12px 28px rgba(0,0,0,.04);
}
h2 { margin: 0 0 10px; font-size: 1.35rem; }
h3 { margin: 22px 0 6px; font-size: 1.05rem; }
ul { padding-left: 1.2em; }
code {
  background: color-mix(in srgb, var(--line) 75%, transparent);
  border-radius: 6px;
  padding: 0 6px;
}
.notice {
  border-left: 4px solid var(--accent);
  padding-left: 14px;
  color: var(--muted);
}
.footer {
  color: var(--muted);
  font-size: .9rem;
  padding: 28px 0 56px;
}