:root {
  --primary: #1A4DFF;
  --accent: #00C2FF;
  --dark: #0F172A;
  --light: #F8FAFC;
  --muted: #64748B;
  --line: #DBE5FF;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; font-family: Inter, system-ui, sans-serif; background: var(--light); color: var(--dark); }
.container { width: min(980px, 92vw); margin: 0 auto; }
.header { padding: 48px 0 24px; background: linear-gradient(135deg, #eef3ff, #f7fcff); border-bottom: 1px solid var(--line); }
.header h1 { margin: 0 0 8px; }
.header p { margin: 0; color: var(--muted); }
.back { display: inline-block; margin-bottom: 8px; color: var(--primary); text-decoration: none; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; padding: 24px 0; }
.stack { display: grid; gap: 14px; padding: 24px 0; }
.card { display: block; text-decoration: none; color: inherit; background: white; border: 1px solid var(--line); border-radius: 12px; padding: 18px; }
.card h2 { margin: 0 0 10px; }
.card p { margin: 0; color: #334155; }
ul { margin: 10px 0 0 18px; }
pre { margin: 0; padding: 12px; border-radius: 10px; overflow: auto; background: #0f172a; color: #dbeafe; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.footer { border-top: 1px solid var(--line); padding: 24px 0; color: var(--muted); }
@media (max-width: 768px) { .grid { grid-template-columns: 1fr; } }