.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: transparent;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 32px;
}

.header-card {
  margin-top: 10px;
  margin-bottom: 6px;
  border-radius: 18px;
  background: linear-gradient(
    180deg,
    rgba(224, 241, 255, 0.8) 0%,
    rgba(245, 249, 255, 0.8) 100%
  );
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
}

/* Desktop header card (>=901px) */
@media (min-width: 901px) {
  .brand img {
    height: 34px;
  }
  .nav-desktop {
    display: flex;
    gap: 32px;
    align-items: center;
  }
  .nav-desktop a {
    color: #374151;
    font-weight: 600;
    opacity: 0.9;
    padding: 8px 10px;
    border-radius: 10px;
  }
  .nav-desktop a:hover {
    background: rgba(230, 240, 255, 0.6);
  }
  .nav-collapse {
    display: none;
  }
  .mobmenu-toggle {
    display: none;
  }
}

/* Mobile layout (<=900px) */
@media (max-width: 900px) {
  .brand img {
    height: 22px;
  }
  .nav-desktop {
    display: none;
  }
  .mobmenu-toggle {
    --line: 2px;
    width: 24px;
    height: 24px;
    display: grid;
    gap: 6px;
    background: transparent;
    border: 0;
    padding: 0;
    cursor: pointer;
    z-index: 50;
  }
  .mobmenu-toggle .bar {
    height: var(--line);
    background: #111827;
    border-radius: 2px;
    transition: transform 0.25s ease, opacity 0.2s ease;
  }
  .mobmenu-toggle.is-open .bar:nth-child(1) {
    transform: translateY(10px) rotate(45deg);
  }
  .mobmenu-toggle.is-open .bar:nth-child(2) {
    opacity: 0;
  }
  .mobmenu-toggle.is-open .bar:nth-child(3) {
    transform: translateY(-10px) rotate(-45deg);
  }

  .nav-collapse {
    overflow: hidden;
    height: 0;
    transition: height 0.28s ease, opacity 0.28s ease, transform 0.28s ease;
    opacity: 0;
    transform: translateY(-6px);
    padding: 0 12px;
  }
  .nav-collapse.opening,
  .nav-collapse.open {
    opacity: 1;
    transform: translateY(0);
  }

  .nav-mobile {
    padding: 14px 16px;
  }

  .moblink {
    display: block;
    font-size: 22px;
    line-height: 1.6;
    color: #0f172a;
    padding: 12px 6px;
    border-radius: 12px;
  }
  .moblink:active,
  .moblink:focus {
    background: rgba(230, 240, 255, 0.6);
    outline: none;
  }
}