:root {
  --primary: #0b3d91;
  --accent: #1f6feb;
  --text: #222222;
  --muted: #6b7280;
  --bg: #f8fafc;
  --white: #ffffff;
}
* { box-sizing: border-box; }
html, body { margin:0; padding:0; }
body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}
header {
  background: var(--white);
  border-bottom: 1px solid #e5e7eb;
  position: sticky; top: 0; z-index: 10;
}
.bar { max-width: 1000px; margin: 0 auto; padding: 14px 20px; display:flex; align-items:center; gap:16px; }
.brand { font-weight: 700; color: var(--primary); letter-spacing: .2px; }
.tag { color: var(--muted); font-size: 14px; }
.nav { margin-left:auto; display:flex; flex-wrap:wrap; align-items:center; gap: 6px;}
.nav a {
  color: var(--text);
  text-decoration: none;
  padding: 8px 10px;
  border-radius: 8px;
}
.nav a:hover { background: #eef2ff; color: var(--primary); }
.nav-toggle { display:none; margin-left:auto; background: var(--primary); color:#fff; border:0; padding:8px 10px; border-radius:8px; }
main { max-width: 1000px; margin: 0 auto; padding: 32px 20px; }
h1 { color: var(--primary); margin: 0 0 12px 0; }
h2 { color: var(--primary); margin-top: 28px; }
.card { background: var(--white); border: 1px solid #e5e7eb; border-radius: 14px; padding: 22px; box-shadow: 0 1px 2px rgba(0,0,0,.04);}
footer { border-top: 1px solid #e5e7eb; background: var(--white); }
.foot { max-width: 1000px; margin: 0 auto; padding: 18px 20px; font-size: 14px; color: var(--muted); display:flex; justify-content:space-between; flex-wrap:wrap; gap:10px;}
ul { padding-left: 20px; }
.muted { color: var(--muted); }
.grid { display:grid; grid-template-columns: repeat(auto-fit,minmax(260px,1fr)); gap:16px; }
a.button { background: var(--primary); color:#fff; padding:10px 14px; border-radius:10px; text-decoration:none; display:inline-block; }
details { margin-bottom:14px; border:1px solid #e5e7eb; border-radius:10px; padding:12px; background:var(--white);}
summary { font-weight:600; cursor:pointer; color:var(--primary);}
summary:hover { color:var(--accent);}

/* Responsive nav */
@media (max-width: 820px) {
  .nav { display:none; width:100%; }
  .nav[aria-expanded="true"] { display:flex; flex-direction:column; align-items:flex-start; padding:10px 0; }
  .nav-toggle { display:block; }
  .bar { flex-wrap:wrap; }
}