/* ============================================
   Terra Lanna TRAVEL — HEADER CSS
   Sticky navigation header
   ============================================ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 1000;
  background: rgba(8, 8, 16, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition);
}

.site-header.scrolled {
  background: rgba(8, 8, 16, 0.97);
  box-shadow: 0 4px 30px rgba(0, 87, 255, 0.15);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- LOGO --- */
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  cursor: pointer;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-blue), var(--color-red));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1;
}

.logo-main {
  font-family: var(--font-display);
  font-size: 1.3rem;
  letter-spacing: 0.08em;
  color: var(--color-white);
}

.logo-sub {
  font-family: var(--font-heading);
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-blue-glow);
  font-weight: 600;
}

/* --- NAV --- */
.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
  justify-content: center;
}

.nav-link {
  padding: 8px 14px;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-muted);
  border-radius: var(--radius);
  transition: all var(--transition);
  white-space: nowrap;
  cursor: pointer;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--color-blue-glow);
  transform: scaleX(0);
  transition: transform var(--transition);
  border-radius: 2px;
}

.nav-link:hover {
  color: var(--color-white);
  background: rgba(255,255,255,0.05);
}

.nav-link:hover::after,
.nav-link.active::after {
  transform: scaleX(1);
}

.nav-link.active {
  color: var(--color-blue-glow);
}

/* --- HEADER RIGHT --- */
.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

/* --- LANGUAGE SWITCHER --- */
.lang-switcher {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn:hover {
  border-color: var(--color-blue-glow);
  background: rgba(0, 87, 255, 0.1);
}

.lang-flag {
  font-size: 1rem;
  line-height: 1;
}

.lang-arrow {
  font-size: 0.6rem;
  transition: transform var(--transition);
}

.lang-switcher.open .lang-arrow {
  transform: rotate(180deg);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  min-width: 160px;
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(0,0,0,0.5);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition);
  z-index: 100;
}

.lang-switcher.open .lang-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  cursor: pointer;
  transition: background var(--transition);
  font-family: var(--font-heading);
  font-size: 0.9rem;
  border-bottom: 1px solid var(--color-border);
}

.lang-option:last-child {
  border-bottom: none;
}

.lang-option:hover {
  background: rgba(0, 87, 255, 0.15);
}

.lang-option.active {
  color: var(--color-blue-glow);
  background: rgba(0, 87, 255, 0.1);
}

/* --- MOBILE MENU BUTTON --- */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  cursor: pointer;
}

.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-white);
  border-radius: 2px;
  transition: all var(--transition);
}

.mobile-menu-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-menu-btn.open span:nth-child(2) { opacity: 0; }
.mobile-menu-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* --- MOBILE NAV --- */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: rgba(8, 8, 16, 0.97);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  padding: 16px 24px 24px;
  z-index: 999;
  transform: translateY(-100%);
  transition: transform var(--transition-slow);
}

.mobile-nav.open {
  transform: translateY(0);
}

.mobile-nav .nav-link {
  display: block;
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 1rem;
}

.mobile-nav .nav-link:last-child {
  border-bottom: none;
}

/* --- SPACER --- */
.header-spacer {
  height: var(--header-height);
}

/* --- RESPONSIVE --- */
@media (max-width: 900px) {
  .site-nav { display: none; }
  .mobile-menu-btn { display: flex; }
  .mobile-nav { display: block; }
  .logo-text .logo-sub { display: none; }
}

@media (max-width: 480px) {
  .logo-main { font-size: 1.1rem; }
}