:root {
  --teal: #0f9e99;
  --teal-deep: #044d57;
  --ink: #10201f;
  --muted: #5b6b6a;
  --bg: #f6fbfa;
  --card: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8f1f0;
    --muted: #9db3b1;
    --bg: #0c1514;
    --card: #14201f;
  }
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
}
header {
  background: linear-gradient(135deg, #139e94, var(--teal-deep));
  color: #fff;
  padding: 3.5rem 1.5rem 3rem;
  text-align: center;
}
header img { width: 88px; height: 88px; border-radius: 22px; box-shadow: 0 10px 30px rgba(0,0,0,.3); }
header h1 { font-size: 2rem; margin-top: 1rem; letter-spacing: -.02em; }
header p { opacity: .85; max-width: 34rem; margin: .5rem auto 0; }
nav { margin-top: 1.5rem; }
nav a {
  color: #fff; text-decoration: none; font-weight: 600;
  margin: 0 .75rem; padding: .45rem 1.1rem;
  border: 1.5px solid rgba(255,255,255,.5); border-radius: 999px;
  transition: background .2s;
}
nav a:hover, nav a[aria-current] { background: rgba(255,255,255,.18); }
main { max-width: 44rem; margin: 0 auto; padding: 2.5rem 1.5rem 4rem; }
h2 { font-size: 1.35rem; margin: 2.2rem 0 .6rem; letter-spacing: -.01em; }
h2:first-child { margin-top: 0; }
p, li { color: var(--muted); }
main strong { color: var(--ink); }
ul { padding-left: 1.3rem; margin: .4rem 0 1rem; }
a { color: var(--teal); }
.card {
  background: var(--card); border-radius: 16px; padding: 1.5rem;
  margin: 1rem 0; box-shadow: 0 2px 12px rgba(4,77,87,.08);
}
.updated { font-size: .85rem; margin-top: 2.5rem; }
footer {
  text-align: center; padding: 2rem 1rem 3rem;
  font-size: .85rem; color: var(--muted);
}
footer a { color: var(--muted); }