/* ===== 公共导航样式（以首页为准，全站共用）===== */
:root {
  --cyan: #00f5ff;
  --pink: #ff2bd6;
  --line: rgba(0, 245, 255, 0.28);
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 1.4rem;
}
.brand {
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
  text-shadow: 0 0 12px rgba(0,245,255,0.45);
  text-decoration: none;
  cursor: pointer;
}
.brand:hover { color: var(--cyan); }
.nav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.nav a {
  display: inline-flex;
  align-items: center;
  padding: 0.42rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(0, 245, 255, 0.06);
  color: var(--cyan);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  box-shadow: 0 0 0 1px rgba(255,43,214,0.08), 0 0 18px rgba(0,245,255,0.08);
  transition: 0.15s ease;
}
.nav a:hover {
  border-color: var(--pink);
  color: #fff;
  background: rgba(0, 245, 255, 0.06);
  box-shadow: 0 0 18px rgba(255,43,214,0.25);
}
.nav a.active {
  color: #04131a;
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 18px rgba(0,245,255,.45), 0 0 36px rgba(0,245,255,.18);
}
@media (max-width: 720px) {
  .topbar { align-items: flex-start; flex-direction: column; }
}