body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  margin: 0;
  background: #fff;
  color: #000;
}

/* ── Top navigation ── */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 200;
  width: 100%;
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  height: 60px;
  background: rgba(17, 24, 39, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  text-align: center;
}

.nav-links {
  display: flex;
  gap: 2px;
  list-style: none;
  margin: 0 auto;
  padding: 0;
}

.nav-links a {
  font-family: 'Inter', sans-serif;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 6px;
  position: relative;
  transition: color 0.2s, background 0.2s;
}

.nav-links a:hover { color: #fff; background: rgba(255, 255, 255, 0.08); opacity: 1; }

/* ── Card ── */
main {
  flex: 1;
  display: flex;
  padding: 84px 16px 24px;
}

.card {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
  max-width: 300px;
  width: 100%;
  margin: auto;
  text-align: center;
  background: #fff;
}

.title {
  color: #595959;
  font-size: 18px;
}

.card a {
  text-decoration: none;
  font-size: 22px;
  color: #000;
  display: inline-block;
  padding: 4px 6px;
}

.card a.contact-button {
  display: block;
  padding: 8px;
  color: #fff;
  background-color: #000;
  font-size: 18px;
  font-family: system-ui, sans-serif;
}

.card a:hover { opacity: 0.7; }

@media (max-width: 900px) {
  nav { padding: 0 16px; }
}

/* ── Dark mode ── */
html[data-theme="dark"] body { background: #0d1117; color: #e6e9ed; }
html[data-theme="dark"] .card { background: #161b22; box-shadow: 0 4px 14px rgba(0, 0, 0, 0.5); }
html[data-theme="dark"] .title { color: #a3acb6; }
html[data-theme="dark"] .card a { color: #e6e9ed; }
html[data-theme="dark"] .card a.contact-button { background: #e6e9ed; color: #0d1117; }