/* ========================================
   Mobile-First Navigation System
   Conversion-focused, accessible, intuitive
   ======================================== */

/* ========================================
   HEADER & NAVIGATION
   ======================================== */

/* Header Container */
.header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: white;
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base);
}

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

/* Header Content */
.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-4);
  height: 64px;
  padding: var(--spacing-3) var(--spacing-4);
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  text-decoration: none;
  color: var(--color-text);
  font-weight: var(--font-weight-bold);
  font-size: var(--font-size-lg);
  flex-shrink: 0;
}

.logo-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.logo-text {
  display: none; /* Hidden on small mobile */
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: none;
  border-radius: var(--radius-base);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.mobile-menu-toggle:hover {
  background: var(--color-background-alt);
}

.mobile-menu-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.mobile-menu-toggle .hamburger {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mobile-menu-toggle .hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.mobile-menu-toggle.active .hamburger span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle.active .hamburger span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active .hamburger span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Desktop Navigation */
.desktop-nav {
  display: none; /* Hidden on mobile */
}

/* Mobile Navigation Menu */
.mobile-nav {
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  bottom: 0;
  background: white;
  overflow-y: auto;
  transform: translateX(-100%);
  transition: transform var(--transition-base);
  z-index: var(--z-fixed);
}

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

.mobile-nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: calc(var(--z-fixed) - 1);
}

.mobile-nav-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* Mobile Navigation Items */
.mobile-nav-list {
  padding: var(--spacing-4);
}

.mobile-nav-item {
  border-bottom: 1px solid var(--color-border);
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-4);
  color: var(--color-text);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  transition: background var(--transition-fast);
}

.mobile-nav-link:hover {
  background: var(--color-background-alt);
}

.mobile-nav-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
}

/* Mobile Submenu */
.mobile-nav-submenu {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
  background: var(--color-background-alt);
}

.mobile-nav-submenu.active {
  max-height: 500px;
}

.mobile-nav-submenu-item {
  padding: var(--spacing-3) var(--spacing-6);
  border-bottom: 1px solid var(--color-border-light);
}

.mobile-nav-submenu-link {
  color: var(--color-text-light);
  text-decoration: none;
  font-size: var(--font-size-sm);
}

.mobile-nav-submenu-link:hover {
  color: var(--color-primary);
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

/* Header Action Buttons */
.header-action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: none;
  border-radius: var(--radius-base);
  cursor: pointer;
  position: relative;
  transition: background var(--transition-fast);
}

.header-action-btn:hover {
  background: var(--color-background-alt);
}

.header-action-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.header-action-btn svg {
  width: 24px;
  height: 24px;
  color: var(--color-text);
}

/* Cart Badge */
.cart-badge {
  position: absolute;
  top: 4px;
  right: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  background: var(--color-error);
  color: white;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-bold);
  border-radius: var(--radius-full);
  opacity: 0;
  transform: scale(0);
  transition: all var(--transition-base);
}

.cart-badge.active {
  opacity: 1;
  transform: scale(1);
}

/* Search Bar */
.header-search {
  display: none; /* Hidden on mobile */
}

/* User Menu */
.user-menu {
  display: flex;
  align-items: center;
}

/* ========================================
   BOTTOM NAVIGATION (Mobile)
   ======================================== */

.bottom-nav {
  display: flex;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: white;
  border-top: 1px solid var(--color-border);
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
  z-index: var(--z-sticky);
  padding-bottom: env(safe-area-inset-bottom);
}

.bottom-nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-1);
  padding: var(--spacing-2) var(--spacing-1);
  background: transparent;
  border: none;
  color: var(--color-text-light);
  text-decoration: none;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
  min-height: 56px;
}

.bottom-nav-item:hover {
  color: var(--color-primary);
}

.bottom-nav-item:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.bottom-nav-item.active {
  color: var(--color-primary);
}

.bottom-nav-item svg {
  width: 24px;
  height: 24px;
}

.bottom-nav-badge {
  position: absolute;
  top: 8px;
  right: calc(50% - 20px);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 18px;
  height: 18px;
  padding: 0 4px;
  background: var(--color-error);
  color: white;
  font-size: 10px;
  font-weight: var(--font-weight-bold);
  border-radius: var(--radius-full);
}

/* ========================================
   BREADCRUMB NAVIGATION
   ======================================== */

.breadcrumb {
  padding: var(--spacing-3) 0;
  background: var(--color-background-alt);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-2);
  list-style: none;
  margin: 0;
  padding: 0;
}

.breadcrumb-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

.breadcrumb-item:not(:last-child)::after {
  content: '/';
  color: var(--color-text-lighter);
}

.breadcrumb-link {
  color: var(--color-text-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.breadcrumb-link:hover {
  color: var(--color-primary);
}

.breadcrumb-item[aria-current="page"] {
  color: var(--color-text);
  font-weight: var(--font-weight-medium);
}

/* ========================================
   RESPONSIVE BREAKPOINTS
   ======================================== */

/* Tablet (768px and up) */
@media (min-width: 768px) {
  .logo-text {
    display: block;
  }
  
  .mobile-menu-toggle {
    display: none;
  }
  
  .mobile-nav {
    display: none;
  }
  
  .bottom-nav {
    display: none;
  }
  
  .desktop-nav {
    display: block;
  }
  
  .desktop-nav-list {
    display: flex;
    align-items: center;
    gap: var(--spacing-6);
    list-style: none;
    margin: 0;
    padding: 0;
  }
  
  .desktop-nav-link {
    color: var(--color-text);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-sm);
    padding: var(--spacing-2) 0;
    position: relative;
    transition: color var(--transition-fast);
  }
  
  .desktop-nav-link:hover {
    color: var(--color-primary);
  }
  
  .desktop-nav-link:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
  }
  
  .desktop-nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width var(--transition-base);
  }
  
  .desktop-nav-link:hover::after {
    width: 100%;
  }
  
  .header-search {
    display: block;
    position: relative;
    width: 300px;
  }
  
  .search-input {
    width: 100%;
    padding: var(--spacing-2) var(--spacing-4) var(--spacing-2) var(--spacing-10);
    font-size: var(--font-size-sm);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    background: var(--color-background-alt);
    transition: all var(--transition-fast);
  }
  
  .search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    background: white;
    box-shadow: 0 0 0 3px var(--color-primary-light);
  }
  
  .search-icon {
    position: absolute;
    left: var(--spacing-3);
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    height: 18px;
    color: var(--color-text-light);
    pointer-events: none;
  }
  
  .user-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
  }
  
  .user-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--color-primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
    cursor: pointer;
    transition: all var(--transition-fast);
  }
  
  .user-avatar:hover {
    background: var(--color-primary);
    color: white;
  }
  
  .mobile-header .user-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: var(--spacing-2);
    min-width: 200px;
    background: white;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-base);
  }
  
  .mobile-header .user-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
  
  .user-dropdown-item {
    display: block;
    padding: var(--spacing-3) var(--spacing-4);
    color: var(--color-text);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: background var(--transition-fast);
  }
  
  .user-dropdown-item:hover {
    background: var(--color-background-alt);
  }
  
  .user-dropdown-item:first-child {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  }
  
  .user-dropdown-item:last-child {
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  }
}

/* Large Desktop (1200px and up) */
@media (min-width: 1200px) {
  .header-search {
    width: 400px;
  }
}

/* ========================================
   ACCESSIBILITY
   ======================================== */

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  .mobile-nav,
  .mobile-nav-overlay,
  .cart-badge,
  .bottom-nav-item,
  .desktop-nav-link::after,
  .user-dropdown {
    transition: none;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  .header {
    border-bottom-width: 2px;
  }
  
  .mobile-nav-link:hover,
  .desktop-nav-link:hover {
    text-decoration: underline;
  }
}

/* Focus Styles for Keyboard Navigation */
.header-action-btn:focus-visible,
.mobile-menu-toggle:focus-visible,
.bottom-nav-item:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ========================================
   ANIMATIONS
   ======================================== */

@keyframes slideInRight {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.mobile-nav.active {
  animation: slideInRight var(--transition-base);
}

.mobile-nav-overlay.active {
  animation: fadeIn var(--transition-base);
}