.header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(8, 11, 20, 0.85);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav-shell { display: flex; align-items: center; gap: 1rem; min-height: 76px; }
.brand { display: flex; align-items: center; gap: .7rem; }
.brand-mark {
  width: 2rem; height: 2rem; border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #061225; display: grid; place-items: center; font-weight: 800;
}
.brand-copy { display: flex; flex-direction: column; }
.brand-name { font-weight: 700; }
.brand-sub { color: var(--muted); font-size: .8rem; }
.nav { margin-left: auto; display: flex; gap: 1rem; align-items: center; }
.nav a { color: #d7deef; }
.btn { border-radius: 12px; padding: .6rem .9rem; border: 1px solid var(--border); }
.btn-primary { background: linear-gradient(135deg, #2588ff, #4ca8ff); color: #041227; font-weight: 700; border: 0; }
@media (max-width: 900px) {
  .brand-sub, .nav { display: none; }
  .nav-shell { justify-content: space-between; }
}