:root {
  --bg: #f7f8fb; --card: #ffffff; --text: #18202f; --muted: #5a6475; --line: #e3e7ef;
  --accent: #1f55e0; --accent-soft: #e8eefc;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f131b; --card: #171c27; --text: #e8ecf3; --muted: #9aa4b5; --line: #2a3242;
          --accent: #7ea2ff; --accent-soft: #1d2740; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text);
       font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Sans", "Noto Sans JP", sans-serif; }
main { max-width: 760px; margin: 0 auto; padding: 32px 16px 64px; }
header { display: flex; align-items: center; gap: 14px; margin-bottom: 8px; }
header img { width: 56px; height: 56px; border-radius: 14px; }
h1 { font-size: 1.7rem; margin: 0; }
h2 { font-size: 1.2rem; margin: 2rem 0 .5rem; }
h3 { font-size: 1rem; margin: 1.2rem 0 .3rem; }
p, li { color: var(--text); }
.sub { color: var(--muted); margin: 0 0 1rem; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 4px 20px 16px; margin: 16px 0; }
.lang { display: flex; gap: 8px; margin: 12px 0 0; }
.lang a { padding: 4px 12px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); text-decoration: none; font-size: .9rem; }
a { color: var(--accent); }
footer { color: var(--muted); font-size: .85rem; margin-top: 40px; }