:root {
  --bg: #f6f8f5;
  --card: #ffffff;
  --text: #1f2a22;
  --sub: #4d5b51;
  --border: #d8e0da;
  --primary: #2f7d4f;
  --on-primary: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121714;
    --card: #1b221d;
    --text: #eef3ef;
    --sub: #b4c0b7;
    --border: #2c3830;
    --primary: #4fae76;
    --on-primary: #0d1a12;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  font-size: 17px;
  line-height: 1.7;
}
main { max-width: 520px; margin: 0 auto; padding: 32px 16px 48px; }
.logo { font-size: 64px; text-align: center; margin: 0; }
h1 { font-size: 26px; text-align: center; margin: 8px 0 16px; }
h2 { font-size: 19px; margin: 0 0 8px; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 16px; margin: 16px 0; }
.sub { color: var(--sub); font-size: 16px; }
ul { padding-left: 1.2em; margin: 0; }
.button {
  display: flex; align-items: center; justify-content: center;
  min-height: 52px; margin-top: 12px; padding: 12px 16px;
  border-radius: 12px; border: 1px solid var(--border);
  color: var(--text); background: var(--card);
  font-size: 18px; font-weight: 700; text-decoration: none;
}
.button.primary { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
footer { margin-top: 32px; text-align: center; color: var(--sub); font-size: 16px; }
footer a { color: inherit; display: inline-block; min-height: 44px; line-height: 44px; }