/* eCommerce Platform CSS */
/* Mobile-First Professional Corporate Design */

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #16a34a;
    --warning-color: #f59e0b;
    --danger-color: #dc2626;
    --info-color: #0891b2;
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    --radius-sm: 0.25rem;
    --radius: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    
    --transition: all 0.2s ease-in-out;
}

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.container-fluid {
    width: 100%;
    padding: 0 1rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 0.5rem;
}

h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }
h5 { font-size: var(--font-size-base); }
h6 { font-size: var(--font-size-sm); }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: var(--font-size-base);
    font-weight: 500;
    border: 1px solid transparent;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    min-height: 44px; /* Touch-friendly */
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
}

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

.btn-secondary:hover {
    background-color: var(--border-color);
}

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

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

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

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

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: var(--font-size-sm);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: var(--font-size-lg);
}

.btn-block {
    width: 100%;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-control {
    display: block;
    width: 100%;
    padding: 0.75rem;
    font-size: var(--font-size-base);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    transition: var(--transition);
    min-height: 44px; /* Touch-friendly */
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-control::placeholder {
    color: var(--text-muted);
}

.form-select {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.75rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

.form-check {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
}

.form-check-input {
    width: 1.25rem;
    height: 1.25rem;
    margin-right: 0.5rem;
    cursor: pointer;
}

.form-check-label {
    cursor: pointer;
}

/* Header */
.header {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-top {
    background-color: var(--bg-tertiary);
    padding: 0.5rem 0;
    font-size: var(--font-size-sm);
}

.header-main {
    padding: 1rem 0;
}

.header-bottom {
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
}

.logo {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

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

.search-bar {
    position: relative;
    max-width: 500px;
    margin: 0 auto;
}

.search-input {
    width: 100%;
    padding: 0.75rem 3rem 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
}

.search-btn {
    position: absolute;
    right: 0.5rem;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: var(--text-primary);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
}

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

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1rem;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--primary-color);
}

/* Mobile Navigation */
.mobile-header {
    display: none;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

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

.mobile-nav {
    position: fixed;
    top: 0;
    left: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background-color: var(--bg-primary);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    z-index: 1001;
    overflow-y: auto;
}

.mobile-nav.active {
    left: 0;
}

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

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

.mobile-nav-menu {
    list-style: none;
    padding: 1rem;
}

.mobile-nav-link {
    display: block;
    padding: 0.75rem 0;
    color: var(--text-primary);
    font-weight: 500;
    border-bottom: 1px solid var(--border-color);
}

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

.mobile-nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

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

/* Bottom Navigation (Mobile) */
.bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    z-index: 999;
}

.bottom-nav-menu {
    display: flex;
    list-style: none;
}

.bottom-nav-item {
    flex: 1;
    text-align: center;
}

.bottom-nav-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.5rem;
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
    text-decoration: none;
    transition: var(--transition);
}

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

.bottom-nav-icon {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    color: rgba(255, 255, 255, 0.9);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Product Grid */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.product-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
}

.product-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.product-image {
    position: relative;
    padding-top: 100%; /* 1:1 aspect ratio */
    overflow: hidden;
    background-color: var(--bg-tertiary);
}

.product-image img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.product-card:hover .product-image img {
    transform: scale(1.05);
}

.product-badge {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background-color: var(--danger-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius);
    font-size: var(--font-size-xs);
    font-weight: 500;
}

.product-wishlist {
    position: absolute;
    top: 0.5rem;
    left: 0.5rem;
    background-color: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: 50%;
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
}

.product-wishlist:hover {
    background-color: white;
}

.product-wishlist.active {
    color: var(--danger-color);
}

.product-info {
    padding: 1rem;
}

.product-category {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
    margin-bottom: 0.25rem;
}

.product-name {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.product-price {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.price-current {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--primary-color);
}

.price-original {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    text-decoration: line-through;
}

.price-discount {
    font-size: var(--font-size-sm);
    color: var(--danger-color);
    font-weight: 500;
}

.product-rating {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.stars {
    color: var(--warning-color);
    font-size: var(--font-size-sm);
}

.rating-count {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

.product-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-add-cart {
    flex: 1;
}

/* Categories */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
}

.category-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
    text-decoration: none;
    color: var(--text-primary);
}

.category-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow);
}

.category-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.category-name {
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.category-count {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

/* Cart Sidebar */
.cart-sidebar {
    position: fixed;
    top: 0;
    right: -100%;
    width: 400px;
    height: 100vh;
    background-color: var(--bg-primary);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    z-index: 1002;
    display: flex;
    flex-direction: column;
}

.cart-sidebar.active {
    right: 0;
}

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

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

.cart-body {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
}

.cart-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.cart-item-image {
    width: 60px;
    height: 60px;
    object-fit: cover;
    border-radius: var(--radius);
}

.cart-item-info {
    flex: 1;
}

.cart-item-name {
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.cart-item-price {
    color: var(--primary-color);
    font-weight: 500;
}

.cart-item-quantity {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.quantity-btn {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.quantity-input {
    width: 3rem;
    text-align: center;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 0.25rem;
}

.cart-footer {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

.cart-total {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: var(--font-size-lg);
    font-weight: 600;
}

.cart-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

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

/* Login Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1003;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 400px;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: var(--transition);
}

.modal.active .modal-content {
    transform: scale(1);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
}

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

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.login-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.login-tab {
    flex: 1;
    padding: 0.75rem;
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.login-tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.social-login {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.social-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--bg-primary);
    cursor: pointer;
    transition: var(--transition);
}

.social-btn:hover {
    background-color: var(--bg-tertiary);
}

.divider {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 1.5rem 0;
    color: var(--text-muted);
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background-color: var(--border-color);
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    border: 1px solid transparent;
}

.alert-success {
    background-color: #dcfce7;
    border-color: #bbf7d0;
    color: #166534;
}

.alert-warning {
    background-color: #fef3c7;
    border-color: #fde68a;
    color: #92400e;
}

.alert-danger {
    background-color: #fee2e2;
    border-color: #fecaca;
    color: #991b1b;
}

.alert-info {
    background-color: #e0f2fe;
    border-color: #bae6fd;
    color: #0369a1;
}

/* Footer */
.footer {
    background-color: var(--text-primary);
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-top {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-column h4 {
    margin-bottom: 1rem;
    color: white;
}

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

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

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 0.75rem;
    }
    
    .header-top {
        display: none;
    }
    
    .header-main {
        display: none;
    }
    
    .mobile-header {
        display: flex;
    }
    
    .nav-menu {
        display: none;
    }
    
    .bottom-nav {
        display: block;
    }
    
    .hero {
        padding: 2rem 0;
    }
    
    .hero h1 {
        font-size: 1.875rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .product-grid {
        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
        gap: 1rem;
    }
    
    .category-grid {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
        gap: 0.75rem;
    }
    
    .cart-sidebar {
        width: 100%;
        right: -100%;
    }
    
    .modal-content {
        width: 95%;
        margin: 1rem;
    }
    
    .footer-top {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .product-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }
    
    .btn {
        padding: 0.625rem 1rem;
        font-size: var(--font-size-sm);
    }
    
    .form-control {
        padding: 0.625rem;
        font-size: var(--font-size-sm);
    }
    
    .hero h1 {
        font-size: 1.5rem;
    }
    
    .hero p {
        font-size: 0.875rem;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.d-grid { display: grid; }

.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }

.align-center { align-items: center; }
.align-start { align-items: flex-start; }
.align-end { align-items: flex-end; }

.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }

.p-0 { padding: 0; }
.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 0.75rem; }
.p-4 { padding: 1rem; }
.p-6 { padding: 1.5rem; }

.w-full { width: 100%; }
.h-full { height: 100%; }

.rounded { border-radius: var(--radius); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: 50%; }

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

.bg-white { background-color: var(--bg-primary); }
.bg-gray { background-color: var(--bg-secondary); }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }

.font-bold { font-weight: 600; }
.font-medium { font-weight: 500; }
.font-normal { font-weight: 400; }

.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }

.hidden { display: none; }
.visible { visibility: visible; }
.invisible { visibility: hidden; }

/* Loading Spinner */
.spinner {
    width: 1.5rem;
    height: 1.5rem;
    border: 2px solid var(--border-color);
    border-top: 2px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

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

@keyframes slideInUp {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@keyframes slideInDown {
    from { transform: translateY(-20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.fade-in {
    animation: fadeIn 0.3s ease-in-out;
}

.slide-in-up {
    animation: slideInUp 0.3s ease-in-out;
}

.slide-in-down {
    animation: slideInDown 0.3s ease-in-out;
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .bottom-nav,
    .btn,
    .modal {
        display: none !important;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .product-card {
        break-inside: avoid;
        border: 1px solid #ccc !important;
    }
}