/* Header full-width (mờ dần khi cuộn) và footer dùng chung. */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 60; height: var(--header-h);
  background: linear-gradient(135deg, var(--mitc-red-deep), #d21628);
  border-bottom: 1px solid rgba(255, 255, 255, .18);
  transition: height .3s ease, background .3s ease, box-shadow .3s ease, backdrop-filter .3s ease;
}
.site-header::after {
  content: ""; position: absolute; left: 0; bottom: -1px; width: 100%; height: 3px;
  background: linear-gradient(90deg, #fff 0 8%, var(--mitc-yellow) 8% 16%, transparent 40%);
}
.site-header.is-scrolled {
  height: var(--header-h-sm);
  background: rgba(130, 8, 26, .66);
  -webkit-backdrop-filter: blur(16px) saturate(1.5);
  backdrop-filter: blur(16px) saturate(1.5);
  box-shadow: 0 12px 36px rgba(60, 0, 10, .22);
}
.header-inner { height: 100%; display: flex; align-items: center; gap: 28px; }
.brand { display: flex; align-items: center; height: 100%; }
.brand img { height: calc(100% - 14px); width: auto; transition: height .3s; }
.header-nav { display: flex; gap: 4px; margin-left: auto; }
.header-nav a {
  position: relative; padding: 8px 14px; border-radius: 999px; color: rgba(255, 255, 255, .88);
  font-size: 14px; font-weight: 600; text-transform: uppercase; letter-spacing: .3px; transition: color .2s, background .2s;
}
.header-nav a:hover { color: #fff; background: rgba(255, 255, 255, .12); }
.header-nav a.is-active { color: #fff; background: rgba(255, 255, 255, .18); }
.header-cta { background: var(--mitc-yellow); color: var(--ink); padding: 9px 18px; font-size: 14px; }
.header-cta:hover { background: #ffd24d; }
.nav-toggle { display: none; margin-left: auto; width: 44px; height: 44px; border: 1px solid rgba(255, 255, 255, .3); border-radius: 12px; background: rgba(255, 255, 255, .1); cursor: pointer; }
.nav-toggle span { display: block; width: 20px; height: 2px; margin: 5px auto; background: #fff; transition: transform .25s, opacity .25s; }
.nav-open .nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-open .nav-toggle span:nth-child(2) { opacity: 0; }
.nav-open .nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 1080px) {
  .header-cta { display: none; }
}
@media (max-width: 860px) {
  .nav-toggle { display: block; }
  .header-nav {
    position: absolute; top: 100%; left: 0; right: 0; margin: 0; padding: 12px 20px 20px; flex-direction: column;
    background: rgba(110, 6, 22, .96); -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px);
    transform: translateY(-8px); opacity: 0; visibility: hidden; transition: opacity .25s, transform .25s, visibility .25s;
  }
  .nav-open .header-nav { opacity: 1; transform: none; visibility: visible; }
  .header-nav a { padding: 13px 14px; font-size: 15px; }
}

.site-footer { background: var(--ink); color: #e8c9ce; font-size: 14px; }
.site-footer .container { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-block: 22px; }
.site-footer a:hover { color: #fff; }