:root {
  --primary-color: #2563eb;
  --secondary-color: #3b82f6;
  --accent-color: #f59e0b;
  --danger-color: #ef4444;
  --success-color: #10b981;
  --dark-text: #1f2937;
  --light-text: #6b7280;
  --border-color: #e5e7eb;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f3f4f6;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-secondary);
  color: var(--dark-text);
  line-height: 1.6;
  min-height: 100vh;
  padding-bottom: 60px;
}

body.menu-open {
  overflow: hidden;
}

/* Desktop Header */
.board-header {
  background: var(--bg-primary);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.desktop-header {
  display: block;
}

.header-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border-color);
}

.logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  gap: 0.75rem;
}

.logo svg {
  width: 36px;
  height: 36px;
  color: var(--primary-color);
}

.logo-text {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--dark-text);
}

.logo-accent {
  color: var(--primary-color);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.location-selector {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s;
  background: var(--bg-primary);
  position: relative;
  user-select: none;
}

.location-selector:hover {
  border-color: var(--primary-color);
  background: var(--bg-tertiary);
}

.location-selector.active {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.location-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  margin-top: 0.25rem;
  max-height: 300px;
  overflow-y: auto;
  display: none;
}

.location-dropdown.active {
  display: block;
}

.location-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  cursor: pointer;
  transition: background 0.3s;
  border-bottom: 1px solid var(--border-color);
}

.location-item:last-child {
  border-bottom: none;
}

.location-item:hover {
  background: var(--bg-tertiary);
}

.location-item i {
  width: 16px;
  text-align: center;
  color: var(--primary-color);
}

.location-item span {
  flex: 1;
  font-weight: 500;
}

/* Buttons */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 500;
}

.btn-icon-text {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background: var(--secondary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary-color);
  color: var(--primary-color);
}

.btn-outline:hover {
  background: var(--primary-color);
  color: white;
  transform: translateY(-2px);
}

.btn-accent {
  background: var(--accent-color);
  color: white;
}

.btn-accent:hover {
  background: #d97706;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Desktop Navigation */
.nav-container {
  padding: 0.75rem 0;
}

.desktop-nav {
  display: block;
}

.main-nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.nav-link {
  color: var(--dark-text);
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-link i {
  font-size: 1rem;
  opacity: 0.7;
}

.nav-link:hover {
  color: var(--primary-color);
  background: var(--bg-tertiary);
}

/* Mobile Header */
.mobile-header {
  display: none;
  background: var(--bg-primary);
  box-shadow: var(--shadow-md);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
}

.mobile-header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1rem;
  height: 56px;
}

.menu-toggle {
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--dark-text);
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-logo {
  text-decoration: none;
}

.mobile-logo svg {
  width: 32px;
  height: 32px;
  color: var(--primary-color);
}

.mobile-header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.search-toggle, .notification-icon {
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--dark-text);
  cursor: pointer;
  padding: 0.5rem;
  position: relative;
  text-decoration: none;
}

.badge, .menu-badge {
  position: absolute;
  top: 0;
  right: 0;
  background: var(--danger-color);
  color: white;
  font-size: 0.625rem;
  padding: 0.125rem 0.375rem;
  border-radius: 10px;
  min-width: 16px;
  text-align: center;
}

/* Mobile Search */
.mobile-search {
  background: var(--bg-primary);
  padding: 0.5rem 1rem;
  display: none;
  border-top: 1px solid var(--border-color);
}

.mobile-search.active {
  display: block;
}

.mobile-search-container {
  display: flex;
  gap: 0.5rem;
}

.mobile-search-input {
  flex: 1;
  padding: 0.625rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 1rem;
}

.mobile-search-btn {
  padding: 0.625rem 1rem;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

/* Mobile Side Menu */
.mobile-menu-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1998;
}

.mobile-menu-overlay.active {
  display: block;
}

.mobile-side-menu {
  position: fixed;
  top: 0;
  left: -280px;
  width: 280px;
  height: 100%;
  background: var(--bg-primary);
  z-index: 1999;
  transition: left 0.3s ease;
  overflow-y: auto;
}

.mobile-side-menu.active {
  left: 0;
}

.mobile-menu-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.mobile-menu-header h3 {
  font-size: 1.25rem;
}

.close-menu {
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--dark-text);
  cursor: pointer;
}

.mobile-menu-user {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: var(--bg-tertiary);
}

.user-avatar {
  font-size: 2.5rem;
  color: var(--light-text);
}

.user-info p {
  font-size: 0.875rem;
  color: var(--light-text);
  margin-bottom: 0.25rem;
}

.user-info a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
}

.mobile-menu-nav {
  padding: 1rem 0;
}

.mobile-menu-link {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.875rem 1rem;
  color: var(--dark-text);
  text-decoration: none;
  transition: background 0.3s;
  position: relative;
}

.mobile-menu-link:hover {
  background: var(--bg-tertiary);
}

.mobile-menu-link i {
  width: 24px;
  text-align: center;
  color: var(--light-text);
}

/* Mobile Bottom Navigation */
.mobile-bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--bg-primary);
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  padding: 0.5rem 0;
}

.bottom-nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  padding: 0.5rem;
  text-decoration: none;
  color: var(--light-text);
  font-size: 0.75rem;
  transition: color 0.3s;
  position: relative;
}

.bottom-nav-item i {
  font-size: 1.25rem;
}

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

.bottom-nav-add {
  position: relative;
}

.add-button {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--accent-color), #f59e0b);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: var(--shadow-lg);
  position: absolute;
  top: -20px;
  left: 50%;
  transform: translateX(-50%);
}

.add-button i {
  font-size: 1.5rem;
}

.bottom-nav-add span {
  margin-top: 24px;
}

/* Main Content */
.main-content {
  min-height: calc(100vh - 60px);
  padding-top: 0;
}

/* Search Section */
.search-section {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  padding: 3rem 0;
  color: white;
}

.search-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.search-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-align: center;
}

.search-subtitle {
  font-size: 1.2rem;
  text-align: center;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.search-box {
  background: white;
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--shadow-xl);
}

.search-form {
  display: flex;
  gap: 1rem;
}

.search-input-group {
  flex: 1;
  position: relative;
}

.search-input {
  width: 100%;
  padding: 1rem 1rem 1rem 3rem;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.3s;
}

.search-input:focus {
  outline: none;
  border-color: var(--primary-color);
}

.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--light-text);
}

/* Categories */
.categories-section {
  padding: 3rem 0;
  background: var(--bg-primary);
}

.section-title {
  font-size: 2rem;
  margin-bottom: 2rem;
  text-align: center;
  color: var(--dark-text);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1.5rem;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.category-card {
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
  transition: all 0.3s;
  cursor: pointer;
  text-decoration: none;
  color: var(--dark-text);
}

.category-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.category-icon {
  font-size: 3rem;
  margin-bottom: 0.5rem;
}

.category-name {
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.category-count {
  color: var(--light-text);
  font-size: 0.9rem;
}

/* Ads Grid */
.ads-section {
  padding: 3rem 0;
}

.ads-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.filter-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding: 1rem;
  background: var(--bg-primary);
  border-radius: 8px;
}

.filter-options {
  display: flex;
  gap: 1rem;
}

.filter-btn {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-color);
  background: white;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s;
}

.filter-btn:hover {
  border-color: var(--primary-color);
  background: var(--bg-tertiary);
}

.sort-select {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  background: white;
}

.ads-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.ad-card {
  background: var(--bg-primary);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s;
  cursor: pointer;
}

.ad-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.ad-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: var(--bg-tertiary);
}

.ad-content {
  padding: 1rem;
}

.ad-price {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.ad-title {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--dark-text);
}

.ad-description {
  color: var(--light-text);
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.ad-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--light-text);
}

.ad-location,
.ad-date {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* Premium Ads */
.premium-ads {
  background: linear-gradient(135deg, #fef3c7, #fde68a);
  padding: 2rem 0;
  margin-bottom: 3rem;
}

.premium-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.premium-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--dark-text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.premium-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.premium-card {
  background: white;
  border: 2px solid var(--accent-color);
  position: relative;
}

.premium-badge {
  position: absolute;
  top: 10px;
  right: 10px;
  background: var(--accent-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: bold;
  text-transform: uppercase;
  z-index: 1;
}

/* Footer */
.board-footer {
  background: var(--dark-text);
  color: white;
  padding: 3rem 0 1rem;
  margin-top: 5rem;
}

.desktop-footer {
  display: block;
}

.footer-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-column h3 {
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: rgba(255,255,255,0.8);
  text-decoration: none;
  transition: color 0.3s;
}

.footer-links a:hover {
  color: white;
}

.app-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.app-button img {
  height: 40px;
}

.social-links {
  display: flex;
  gap: 1rem;
}

.social-links a {
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  transition: background 0.3s;
}

.social-links a:hover {
  background: var(--primary-color);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
  color: rgba(255,255,255,0.6);
}

/* Tablet Responsive */
@media (max-width: 1024px) {
  .categories-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .ads-grid,
  .premium-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .footer-content {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Mobile Responsive */
@media (max-width: 768px) {
  body {
    padding-top: 56px;
    padding-bottom: 60px;
  }
  
  .desktop-header,
  .desktop-nav,
  .desktop-footer {
    display: none;
  }
  
  .mobile-header {
    display: block;
  }
  
  .mobile-bottom-nav {
    display: flex;
  }
  
  .main-content {
    min-height: calc(100vh - 116px);
  }
  
  .search-section {
    padding: 2rem 0;
  }
  
  .search-title {
    font-size: 1.75rem;
  }
  
  .search-subtitle {
    font-size: 1rem;
  }
  
  .search-box {
    padding: 1rem;
  }
  
  .search-form {
    flex-direction: column;
  }
  
  .search-input {
    padding: 0.875rem 0.875rem 0.875rem 2.5rem;
  }
  
  .categories-section {
    padding: 2rem 0;
  }
  
  .section-title {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
  }
  
  .categories-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
  }
  
  .category-card {
    padding: 1rem;
  }
  
  .category-icon {
    font-size: 2rem;
  }
  
  .category-name {
    font-size: 0.875rem;
  }
  
  .category-count {
    font-size: 0.75rem;
  }
  
  .ads-section {
    padding: 2rem 0;
  }
  
  .filter-bar {
    flex-direction: column;
    gap: 1rem;
    align-items: stretch;
  }
  
  .filter-options {
    width: 100%;
    overflow-x: auto;
  }
  
  .ads-grid,
  .premium-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
  
  .ad-image {
    height: 150px;
  }
  
  .ad-content {
    padding: 0.75rem;
  }
  
  .ad-price {
    font-size: 1.25rem;
  }
  
  .ad-title {
    font-size: 1rem;
  }
  
  .ad-description {
    font-size: 0.875rem;
  }
  
  .premium-ads {
    padding: 1.5rem 0;
    margin-bottom: 2rem;
  }
  
  .btn {
    padding: 0.625rem 1rem;
    font-size: 0.9rem;
  }
  
  .btn-icon-text span {
    display: none;
  }
  
  .location-selector span {
    font-size: 0.875rem;
  }
  
  .board-footer {
    margin-top: 2rem;
    padding-bottom: 4rem;
  }
}

/* Small Mobile */
@media (max-width: 480px) {
  .categories-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .ads-grid,
  .premium-grid {
    grid-template-columns: 1fr;
  }
  
  .header-actions {
    gap: 0.5rem;
  }
  
  .location-selector {
    padding: 0.375rem 0.5rem;
  }
  
  .location-selector span {
    display: none;
  }
  
  .location-selector i:last-child {
    display: none;
  }
}