:root {
  color-scheme: light dark;
  --bg: #f7f5fa;
  --surface: #ffffff;
  --text: #14121a;
  --muted: #5b5766;
  --border: #e4dff0;
  --accent: #6c4bf4;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #100e17;
    --surface: #1b1825;
    --text: #f4f2f9;
    --muted: #b4afc2;
    --border: #302a42;
    --accent: #9b82ff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 0 20px 80px;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Noto Sans JP', sans-serif;
  line-height: 1.9;
  font-size: 16px;
}
main { max-width: 720px; margin: 0 auto; }
header {
  margin: 0 -20px 40px;
  padding: 56px 20px 40px;
  background: linear-gradient(135deg, #6c4bf4, #b14bf4);
  color: #fff;
}
header .inner { max-width: 720px; margin: 0 auto; }
header p { opacity: 0.85; margin: 8px 0 0; }
h1 { font-size: 28px; margin: 0; letter-spacing: -0.02em; }
h2 { font-size: 19px; margin: 40px 0 8px; }
h3 { font-size: 16px; margin: 24px 0 4px; }
p, li { color: var(--text); }
.meta { color: var(--muted); font-size: 14px; }
a { color: var(--accent); }
table { border-collapse: collapse; width: 100%; margin: 16px 0; font-size: 14px; }
th, td { border: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
th { background: var(--surface); }
nav { margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--border); font-size: 14px; }