.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px clamp(18px, 5vw, 64px);
  background: rgba(255, 253, 248, 0.92);
  border-bottom: 1px solid rgba(219, 231, 232, 0.82);
  backdrop-filter: blur(14px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 8px;
  background: var(--blue);
  color: white;
  font-weight: 800;
  transition: transform var(--hover-duration) var(--ease), background-color var(--hover-duration) var(--ease);
}

.brand:hover .brand-mark {
  transform: translateY(-2px) scale(1.03);
  background: var(--aqua);
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: var(--muted);
  font-size: 0.78rem;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.95rem;
}

.main-nav a {
  position: relative;
  text-decoration: none;
  color: var(--blue-dark);
  font-weight: 700;
}

.main-nav a::after {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -7px;
  height: 2px;
  background: var(--aqua);
  content: "";
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--hover-duration) var(--ease);
}

.main-nav a:hover::after,
.main-nav a:focus-visible::after {
  transform: scaleX(1);
}

.admin-link {
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.menu-button {
  display: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: white;
  padding: 9px 12px;
  color: var(--blue-dark);
  font-weight: 700;
}

/* Copyright RZU Informatique */