/* Site header: one markup, two layouts */
.site-header {
  position: sticky;
  top: 0;
  z-index: 3; /* below .w3-modal so dialogs cover it */
  padding: 10px 16px;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid #242429;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 12px;
}

.nav-btn {
  font-weight: bold;
  background: rgba(14, 14, 16, 0.8);
}

.site-nav .w3-button i {
  margin-right: 8px;
}

/* Phones: static 2-column grid, primary button full width */
@media (max-width: 600px) {
  .site-header {
    position: static;
    padding: 8px;
  }

  .site-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .nav-wide {
    grid-column: 1 / -1;
  }

  .site-nav .w3-button {
    text-align: center;
  }
}