/* ============================================
   Header & Navigation
   ============================================ */

/* --- Header Base --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: transparent;
  transition: background var(--transition-base), box-shadow var(--transition-base);
}

.header--scrolled {
  background: var(--color-white);
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

/* --- Logo --- */
.header-logo img {
  height: 36px;
  width: auto;
  display: block;
  background: var(--color-white);
  border-radius: var(--radius-md);
  padding: 4px 8px;
}

.header--scrolled .header-logo img {
  background: transparent;
  padding: 0;
}

/* --- Desktop Nav --- */
.nav-desktop {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-link {
  font-family: var(--font-heading);
  font-weight: var(--font-medium);
  font-size: var(--text-sm);
  color: var(--color-neutral-700);
  text-decoration: none;
  position: relative;
  padding: var(--space-2) 0;
  transition: color var(--transition-base);
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  cursor: pointer;
}

.header:not(.header--scrolled) .nav-link {
  color: rgba(255, 255, 255, 0.85);
}

.header:not(.header--scrolled) .nav-link:hover {
  color: var(--color-white);
}

.header--scrolled .nav-link:hover {
  color: var(--color-primary-500);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  right: 50%;
  height: 2px;
  background: var(--color-primary-500);
  transition: left var(--transition-base), right var(--transition-base);
}

.nav-link:hover::after {
  left: 0;
  right: 0;
}

/* --- Dropdown --- */
.nav-item {
  position: relative;
}

.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  min-width: 280px;
  padding-top: 8px;
  background: var(--color-white);
  box-shadow: var(--shadow-xl);
  border-radius: var(--radius-xl);
  padding: 8px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
}

.nav-dropdown.active,
.nav-item:hover .nav-dropdown {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateX(-50%);
}

.nav-dropdown li a {
  display: block;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  color: var(--color-neutral-700);
  font-size: var(--text-sm);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-dropdown li a:hover {
  background: var(--color-primary-50);
  color: var(--color-primary-600);
}

/* --- Header Buttons --- */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.header-actions .btn {
  padding: 8px 20px;
  font-size: var(--text-sm);
}

.header:not(.header--scrolled) .header-actions .btn-outline {
  color: rgba(255, 255, 255, 0.9);
  border-color: rgba(255, 255, 255, 0.3);
}

.header:not(.header--scrolled) .header-actions .btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.6);
  color: var(--color-white);
}

/* --- Hamburger Menu Toggle --- */
.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  position: relative;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  flex-shrink: 0;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-neutral-700);
  position: absolute;
  left: 10px;
  transition: transform var(--transition-base), opacity var(--transition-fast);
}

.header:not(.header--scrolled) .menu-toggle span {
  background: var(--color-white);
}

.menu-toggle span:nth-child(1) { top: 14px; }
.menu-toggle span:nth-child(2) { top: 21px; }
.menu-toggle span:nth-child(3) { top: 28px; }

.menu-toggle.active span:nth-child(1) {
  top: 21px;
  transform: rotate(45deg);
}
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) {
  top: 21px;
  transform: rotate(-45deg);
}

/* --- Mobile Overlay --- */
.mobile-nav {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.mobile-nav.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* --- Mobile Menu --- */
.mobile-menu {
  position: fixed;
  right: 0;
  top: 0;
  height: 100vh;
  width: 300px;
  background: var(--color-white);
  transform: translateX(100%);
  transition: transform var(--transition-slow);
  padding-top: var(--header-height);
  z-index: 1000;
  overflow-y: auto;
  box-shadow: var(--shadow-2xl);
}

.mobile-menu.active {
  transform: translateX(0);
}

.mobile-nav-list {
  padding: var(--space-4) 0;
}

.mobile-nav-link {
  display: block;
  width: 100%;
  text-align: left;
  padding: var(--space-4) var(--space-6);
  font-family: var(--font-heading);
  font-weight: var(--font-medium);
  font-size: var(--text-lg);
  color: var(--color-neutral-700);
  border-bottom: 1px solid var(--color-neutral-100);
  transition: background var(--transition-fast), color var(--transition-fast);
  cursor: pointer;
}

.mobile-nav-link:hover {
  background: var(--color-neutral-50);
  color: var(--color-primary-500);
}

.mobile-sub {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
  background: var(--color-neutral-50);
}

.mobile-sub.active {
  max-height: 300px;
}

.mobile-sub li a {
  display: block;
  padding: var(--space-3) var(--space-6) var(--space-3) var(--space-10);
  font-size: var(--text-base);
  color: var(--color-neutral-600);
  transition: color var(--transition-fast);
}

.mobile-sub li a:hover {
  color: var(--color-primary-500);
}

.mobile-actions {
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .header {
    height: var(--header-height-mobile);
  }

  .nav-desktop,
  .header-actions {
    display: none;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .mobile-menu {
    padding-top: var(--header-height-mobile);
  }
}