:root {
  --bg: #faf8f2;
  --ink: #23262d;
  --muted: #5c6068;
  --navy: #224678;
  --accent: #c94f1a;
  --card: #ffffff;
  --line: #e4e1d8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15181d;
    --ink: #eceae4;
    --muted: #a6abb3;
    --navy: #7fa6dc;
    --accent: #f0875a;
    --card: #1e2229;
    --line: #2f343c;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "BIZ UDPGothic", "Hiragino Sans", "Noto Sans JP", "Yu Gothic", sans-serif;
  line-height: 1.8;
}
header {
  background: var(--navy);
  color: #fff;
  padding: 28px 16px;
}
@media (prefers-color-scheme: dark) { header { color: #15181d; } }
header .wrap, main, footer { max-width: 720px; margin: 0 auto; }
header h1 { margin: 0; font-size: 1.6rem; letter-spacing: .02em; }
header p { margin: 4px 0 0; opacity: .9; }
main { padding: 24px 16px 8px; }
section {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 20px;
  margin-bottom: 16px;
}
h2 { font-size: 1.15rem; margin: 0 0 8px; color: var(--navy); }
a { color: var(--accent); }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  padding: 10px 18px;
  border-radius: 999px;
  font-weight: bold;
}
ul { padding-left: 1.2em; margin: 6px 0; }
.note { color: var(--muted); font-size: .92rem; }
footer { padding: 8px 16px 32px; color: var(--muted); font-size: .9rem; }
nav a { margin-right: 16px; }