:root {
  color-scheme: light dark;
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #18212f;
  --muted: #667085;
  --border: #e4e7ec;
  --accent: #3157d5;
  --accent-soft: #eef2ff;
  --warning-bg: #fff7ed;
  --warning-border: #fdba74;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1218;
    --card: #171b23;
    --text: #f4f6f8;
    --muted: #a4adbb;
    --border: #2a303b;
    --accent: #8ea6ff;
    --accent-soft: #202a4a;
    --warning-bg: #2b2118;
    --warning-border: #9a6135;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}
.container { max-width: 900px; margin: 0 auto; padding: 32px 20px 64px; }
header {
  display: flex; justify-content: space-between; align-items: center;
  gap: 16px; margin-bottom: 28px;
}
.brand { font-weight: 800; font-size: 1.1rem; text-decoration: none; color: var(--text); }
nav a { margin-left: 16px; }
.hero, .card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 18px; padding: 28px;
}
.hero { margin-bottom: 20px; }
.grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px; margin-top: 22px;
}
h1 { margin: 0 0 10px; font-size: clamp(2rem, 5vw, 3.2rem); line-height: 1.1; }
h2 { margin-top: 30px; font-size: 1.35rem; }
h3 { margin-top: 0; }
p { margin: 10px 0 16px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.button {
  display: inline-block; padding: 10px 14px; border-radius: 10px;
  background: var(--accent); color: white; font-weight: 700; margin-right: 8px;
}
.button:hover { text-decoration: none; opacity: .92; }
.muted { color: var(--muted); }
.notice {
  padding: 16px; border-radius: 12px; background: var(--accent-soft);
  border: 1px solid var(--border); margin: 18px 0;
}
.warning { background: var(--warning-bg); border-color: var(--warning-border); }
footer { margin-top: 34px; color: var(--muted); font-size: .92rem; }
code { padding: 2px 6px; border: 1px solid var(--border); border-radius: 6px; }
ul { padding-left: 22px; }