:root {
  --bg: #f6f7fb; --card: #ffffff; --text: #1f2430; --muted: #5d6475; --accent: #2f9e88; --line: #e4e7ef;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #14161c; --card: #1d2029; --text: #eceef3; --muted: #a3a9b8; --accent: #5cc8b0; --line: #2c303b; }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Helvetica Neue", sans-serif;
}
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 64px; }
header { text-align: center; margin-bottom: 24px; }
header img { width: 96px; height: 96px; border-radius: 22px; box-shadow: 0 6px 20px rgba(0,0,0,.12); }
h1 { font-size: 1.6rem; margin: 12px 0 4px; }
.sub { color: var(--muted); margin: 0; }
nav { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; margin: 16px 0 8px; }
nav a { color: var(--accent); text-decoration: none; padding: 6px 14px; border: 1px solid var(--line); border-radius: 999px; background: var(--card); }
section { background: var(--card); border-radius: 18px; padding: 20px 22px; margin: 16px 0; border: 1px solid var(--line); }
h2 { font-size: 1.2rem; margin: 0 0 8px; }
h3 { font-size: 1rem; margin: 18px 0 4px; }
p, li { color: var(--text); }
.muted { color: var(--muted); font-size: .9rem; }
a { color: var(--accent); }
.button { display: inline-block; background: var(--accent); color: #fff; text-decoration: none; padding: 10px 18px; border-radius: 12px; font-weight: 600; }
footer { text-align: center; color: var(--muted); font-size: .85rem; margin-top: 32px; }