:root {
  color-scheme: light dark;
  --bg: #E8EDF5;
  --card: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #5b6470;
  --accent: #1a472a;
  --accent-light: rgba(26, 71, 42, 0.1);
  --border: rgba(0, 0, 0, 0.08);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0b0b;
    --card: #1c1c1e;
    --text: #f0f0f2;
    --text-secondary: #9aa3ad;
    --accent: #4ea66d;
    --accent-light: rgba(78, 166, 109, 0.15);
    --border: rgba(255, 255, 255, 0.08);
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, Segoe UI, Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 22px 80px;
}
header.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
header.brand .logo {
  width: 32px;
  height: 32px;
  background: var(--accent);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 14px;
}
header.brand .name { font-weight: 700; font-size: 16px; }
header.brand .spacer { flex: 1; }
header.brand a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  margin-left: 14px;
}
header.brand a.active { color: var(--text); font-weight: 600; }
.lang-switch {
  display: inline-flex;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 20px;
}
.lang-switch button {
  background: none;
  border: none;
  padding: 6px 14px;
  font-size: 13px;
  cursor: pointer;
  color: var(--text-secondary);
  font-weight: 500;
}
.lang-switch button.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 700;
}
h1 { font-size: 28px; margin: 18px 0 6px; line-height: 1.2; letter-spacing: -0.5px; }
.updated { color: var(--text-secondary); font-size: 13px; margin-bottom: 32px; }
h2 {
  font-size: 18px;
  margin: 28px 0 8px;
  letter-spacing: -0.2px;
}
p, li { color: var(--text); }
p { margin: 10px 0; }
ul { padding-left: 22px; }
li { margin: 6px 0; }
strong { font-weight: 600; }
a { color: var(--accent); }
.lang { display: none; }
.lang.active { display: block; }
footer {
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding-top: 24px;
  font-size: 13px;
  color: var(--text-secondary);
}