:root {
  --brand: #1565c0;
  --brand-dark: #0d47a1;
  --accent: #f9a825;
  --ink: #1a2433;
  --muted: #5b6676;
  --bg: #f6f9fd;
  --card: #ffffff;
  --line: #dbe4ef;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --brand: #90caf9;
    --brand-dark: #bbdefb;
    --ink: #e8eef6;
    --muted: #a7b3c2;
    --bg: #0f1722;
    --card: #182333;
    --line: #2a3a50;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans Devanagari", sans-serif;
}
a { color: var(--brand); }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }
header.top { border-bottom: 1px solid var(--line); background: var(--card); }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; min-height: 60px; gap: 12px; }
.logo { font-weight: 800; font-size: 20px; color: var(--ink); text-decoration: none; }
.logo span { color: var(--brand); }
nav a { margin-left: 16px; text-decoration: none; color: var(--muted); font-weight: 600; }
.hero { padding: 48px 0 32px; }
.hero h1 { font-size: clamp(28px, 6vw, 44px); line-height: 1.15; margin: 0 0 12px; }
.hero p.lead { font-size: 19px; color: var(--muted); max-width: 680px; margin: 0 0 20px; }
.hi { color: var(--muted); }
.btn {
  display: inline-block; padding: 12px 20px; border-radius: 12px; font-weight: 700;
  text-decoration: none; background: var(--brand); color: #fff;
}
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .btn { color: #0f1722; } }
.btn.ghost { background: transparent; color: var(--brand); border: 2px solid var(--brand); }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }
section { padding: 28px 0; }
section h2 { font-size: 26px; margin: 0 0 16px; }
.tag { display: inline-block; font-size: 13px; font-weight: 700; padding: 2px 10px; border-radius: 99px; background: var(--accent); color: #1a2433; }
details { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin-bottom: 10px; }
summary { font-weight: 700; cursor: pointer; }
.doc { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 24px; margin: 24px 0; }
.doc h1 { margin-top: 0; }
.doc h2 { font-size: 20px; margin-top: 28px; }
footer { border-top: 1px solid var(--line); padding: 24px 0 40px; color: var(--muted); font-size: 14px; }
footer a { margin-right: 16px; }
@media (max-width: 520px) { nav a { margin-left: 10px; font-size: 14px; } }