:root {
  color-scheme: light dark;
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #14182b;
  --muted: #5b6275;
  --accent: #1954dc;
  --line: rgba(20, 24, 43, 0.1);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #050914;
    --card: #0d1426;
    --text: #e8ecf6;
    --muted: #9aa3b8;
    --accent: #5ea2ff;
    --line: rgba(232, 236, 246, 0.12);
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", sans-serif;
}
header {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 24px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 12px; color: inherit; text-decoration: none; font-weight: 600; font-size: 20px; }
.brand img { width: 40px; height: 40px; border-radius: 9px; }
nav a { color: var(--accent); text-decoration: none; margin-left: 16px; font-size: 15px; }
main {
  max-width: 760px;
  margin: 24px auto 48px;
  padding: 32px 28px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
}
h1 { font-size: 30px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 19px; margin: 32px 0 8px; }
p, li { color: var(--text); }
.meta { color: var(--muted); font-size: 14px; margin: 0 0 24px; }
ul { padding-left: 22px; }
a { color: var(--accent); }
footer { max-width: 760px; margin: 0 auto 40px; padding: 0 24px; color: var(--muted); font-size: 13px; }