:root {
  color-scheme: light dark;
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1d2430;
  --muted: #5d6675;
  --accent: #4f6d8f;
  --line: #e3e6eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171c;
    --card: #1d2128;
    --text: #e8ebf0;
    --muted: #9aa3b2;
    --accent: #8fb0d6;
    --line: #2c323c;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 20px 64px;
}
header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
}
header img {
  width: 64px;
  height: 64px;
  border-radius: 14px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}
header .app { font-size: 22px; font-weight: 700; margin: 0; }
header .tag { color: var(--muted); margin: 0; font-size: 15px; }
nav { margin-top: 4px; font-size: 15px; }
nav a { margin-right: 16px; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 28px 28px 12px;
}
h1 { font-size: 30px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 28px 0 8px; }
p, li { margin: 0 0 14px; }
ul { padding-left: 22px; }
.muted { color: var(--muted); font-size: 15px; }
a { color: var(--accent); }
footer { margin-top: 32px; color: var(--muted); font-size: 14px; text-align: center; }
@media (max-width: 480px) {
  main { padding-top: 28px; }
  .card { padding: 20px 18px 6px; }
  h1 { font-size: 26px; }
}