/* ── Header / Navbar ───────────────────────────────── */
.site-header {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: min(calc(100% - 28px), var(--container));
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  background: rgba(7, 19, 31, 0.72);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  color: #fff;
  transition:
    background var(--transition-base),
    box-shadow var(--transition-base);
}

.site-header.is-scrolled {
  background: rgba(7, 19, 31, 0.92);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  letter-spacing: 0.06em;
}

.brand-logo {
  width: 38px;
  height: 38px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 0.9rem;
  font-weight: 700;
}

.site-nav a,
.nav-dropdown-toggle {
  opacity: 0.82;
  transition:
    opacity 0.2s ease,
    color 0.2s ease,
    background 0.2s ease;
  position: relative;
  padding: 6px 0;
}

.nav-dropdown-toggle {
  border: 0;
  background: transparent;
  color: inherit;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.nav-dropdown-toggle::after {
  content: "⌄";
  font-size: 0.78rem;
  line-height: 1;
  transition: transform 0.2s ease;
}

.site-nav a:hover,
.nav-dropdown:hover .nav-dropdown-toggle,
.nav-dropdown.is-open .nav-dropdown-toggle,
.nav-dropdown-toggle:hover {
  opacity: 1;
  color: var(--acid-green);
}

.nav-dropdown {
  position: relative;
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 16px);
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  min-width: 290px;
  display: grid;
  gap: 4px;
  padding: 12px;
  border-radius: 18px;
  background: rgba(7, 19, 31, 0.96);
  border: 1px solid rgba(255, 255, 255, 0.14);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition:
    opacity 0.2s ease,
    transform 0.2s ease,
    visibility 0.2s ease;
}

.nav-dropdown-menu::before {
  content: "";
  position: absolute;
  top: -10px;
  left: 0;
  right: 0;
  height: 10px;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu,
.nav-dropdown.is-open .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown:hover .nav-dropdown-toggle::after,
.nav-dropdown.is-open .nav-dropdown-toggle::after {
  transform: rotate(180deg);
}

.nav-dropdown-menu a {
  display: block;
  padding: 11px 14px;
  border-radius: 12px;
  white-space: normal;
  line-height: 1.35;
}

.nav-dropdown-menu a:hover {
  background: rgba(185, 255, 102, 0.1);
}

/* Active nav indicator */
.site-nav a.active,
.nav-dropdown.is-active .nav-dropdown-toggle {
  opacity: 1;
  color: var(--acid-green);
}

.site-nav > a.active::after,
.nav-dropdown.is-active .nav-dropdown-toggle::before {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 3px;
  background: var(--acid-green);
  border-radius: 999px;
}

.nav-toggle {
  display: none;
  border: 0;
  background: transparent;
  width: 42px;
  height: 42px;
  padding: 10px;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: #fff;
  margin: 6px 0;
  transition:
    transform 0.3s ease,
    opacity 0.3s ease;
}