:root {
  --bg: #ffffff;
  --fg: #1f2328;
  --muted: #59636e;
  --accent: #1a73e8;
  --border: #d1d9e0;
  --card: #f6f8fa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --fg: #e6edf3;
    --muted: #9198a1;
    --accent: #4493f8;
    --border: #30363d;
    --card: #151b23;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.75;
}

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

header, main, footer {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 16px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

.brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--fg);
  text-decoration: none;
}

nav { display: flex; gap: 16px; flex-wrap: wrap; font-size: 0.95rem; }

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

h1 { font-size: 2rem; line-height: 1.3; margin: 0 0 12px; }
h2 { font-size: 1.3rem; margin: 40px 0 12px; }
h3 { font-size: 1.05rem; margin: 24px 0 8px; }

.lead { font-size: 1.1rem; color: var(--muted); margin: 0 0 24px; }

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  padding: 0;
  list-style: none;
}

.features li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
}

.features strong { display: block; margin-bottom: 4px; }

.meta { color: var(--muted); font-size: 0.9rem; }

table { border-collapse: collapse; width: 100%; font-size: 0.95rem; }
th, td { border: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
th { background: var(--card); }
td code { word-break: break-all; }

.note {
  background: var(--card);
  border-left: 4px solid var(--accent);
  padding: 12px 16px;
  border-radius: 4px;
}

footer {
  padding-top: 20px;
  padding-bottom: 32px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}

footer nav { margin-bottom: 8px; }