/* === Header === */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: var(--z-sticky);
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition-base);
}

.header.is-scrolled {
  border-bottom-color: var(--border-color);
  background: rgba(10, 14, 23, 0.95);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* === Logo === */
.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--fs-xl);
  font-weight: var(--fw-bold);
  color: var(--text-primary);
  z-index: calc(var(--z-overlay) + 1);
}

.header__logo:hover {
  color: var(--text-primary);
}

.header__logo-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--gradient-primary);
  color: white;
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  font-family: var(--font-mono);
}

.header__logo-text span {
  color: var(--accent-primary);
}

/* === Navigation === */
.nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav__link {
  position: relative;
  padding: var(--space-2) var(--space-4);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav__link:hover,
.nav__link.is-active {
  color: var(--text-primary);
}

.nav__link.is-active {
  color: var(--accent-primary);
  background: rgba(var(--accent-primary-rgb), 0.08);
}

/* === Dropdown === */
.nav__dropdown {
  position: relative;
}

.nav__dropdown-trigger {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  background: none;
}

.nav__dropdown-trigger:hover {
  color: var(--text-primary);
}

.nav__dropdown-trigger svg {
  width: 14px;
  height: 14px;
  transition: transform var(--transition-fast);
}

.nav__dropdown:hover .nav__dropdown-trigger svg {
  transform: rotate(180deg);
}

.nav__dropdown:focus-within .nav__dropdown-trigger svg {
  transform: rotate(180deg);
}

.nav__dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  min-width: 220px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-2);
  box-shadow: var(--shadow-xl);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-fast);
}

.nav__dropdown:hover .nav__dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav__dropdown:focus-within .nav__dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav__dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  font-size: var(--fs-sm);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav__dropdown-item:hover {
  background: rgba(var(--accent-primary-rgb), 0.08);
  color: var(--text-primary);
}

.nav__dropdown-icon {
  font-size: var(--fs-lg);
  width: 24px;
  text-align: center;
}

.nav__dropdown-title {
  font-weight: var(--fw-medium);
  color: var(--text-primary);
}

.nav__dropdown-desc {
  color: var(--text-muted);
}

/* === Header Actions === */
.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  z-index: calc(var(--z-overlay) + 1);
}

/* === Language Switcher === */
.lang-switch {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1);
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.lang-switch__btn {
  padding: var(--space-1) var(--space-3);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  background: none;
}

.lang-switch__btn.is-active {
  background: rgba(var(--accent-primary-rgb), 0.15);
  color: var(--accent-primary);
}

/* === Mobile Menu Toggle === */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 28px;
  height: 28px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
}

.menu-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-base);
  transform-origin: center;
}

.menu-toggle.is-open .menu-toggle__bar:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.is-open .menu-toggle__bar:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-open .menu-toggle__bar:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* === Mobile Overlay === */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(10, 14, 23, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: var(--z-overlay);
  padding-top: var(--header-height);
  overflow-y: auto;
}

.nav-overlay.is-open {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.nav-overlay .nav {
  flex-direction: column;
  gap: var(--space-2);
}

.nav-overlay .nav__link {
  font-size: var(--fs-xl);
  padding: var(--space-4) var(--space-8);
}

.nav-overlay .nav__dropdown-trigger {
  font-size: var(--fs-xl);
  padding: var(--space-4) var(--space-8);
}

.nav-overlay .nav__dropdown-menu {
  position: static;
  transform: none;
  opacity: 1;
  visibility: visible;
  background: transparent;
  border: none;
  box-shadow: none;
  padding: 0 var(--space-8);
  min-width: auto;
  display: none;
}

.nav-overlay .nav__dropdown.is-open .nav__dropdown-menu {
  display: block;
}

.nav-overlay .nav__dropdown-item {
  font-size: var(--fs-base);
}

/* === Spacer for fixed header === */
.header-spacer {
  height: var(--header-height);
}