:root {
    --primary-color: #2563eb;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-secondary: #f3f4f6;
    --border-color: #e5e7eb;
    --error-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;
}

[data-theme="dark"] {
    --text-color: #f9fafb;
    --text-light: #d1d5db;
    --bg-color: #111827;
    --bg-secondary: #1f2937;
    --border-color: #374151;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease;
}

.header-top {
    padding: 10px 0;
    background-color: var(--bg-secondary);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

nav a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.btn {
    display: inline-block;
    padding: 12px 24px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn:hover {
    background-color: #1d4ed8;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

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

.btn-secondary:hover {
    background-color: #059669;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.product-card {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.product-image {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.product-info {
    padding: 20px;
}

.product-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text-color);
}

.product-price {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.cart-item {
    display: flex;
    gap: 20px;
    padding: 20px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    margin-bottom: 15px;
}

.cart-image {
    width: 100px;
    height: 100px;
    object-fit: cover;
    border-radius: 6px;
}

.cart-details {
    flex: 1;
}

.cart-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.quantity-input {
    width: 60px;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    text-align: center;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
}

.form-control {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 16px;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: border-color 0.3s ease;
}

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

.alert {
    padding: 15px 20px;
    border-radius: 6px;
    margin-bottom: 20px;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.alert-error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
    border: 1px solid #93c5fd;
}

footer {
    background-color: var(--bg-secondary);
    padding: 40px 0;
    margin-top: 60px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.footer-section h3 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    line-height: 2;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--primary-color);
}

.theme-toggle {
    cursor: pointer;
    padding: 8px 16px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--primary-color);
    color: white;
}

.language-selector {
    display: flex;
    gap: 10px;
}

.language-selector a {
    padding: 6px 12px;
    background-color: var(--bg-secondary);
    border-radius: 4px;
    text-decoration: none;
    color: var(--text-color);
    font-size: 14px;
    transition: all 0.3s ease;
}

.language-selector a:hover,
.language-selector a.active {
    background-color: var(--primary-color);
    color: white;
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
    }

    nav ul {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .product-grid {
        grid-template-columns: 1fr;
    }

    .cart-item {
        flex-direction: column;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}

.table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.table th,
.table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background-color: var(--bg-secondary);
    font-weight: 600;
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 500;
}

.badge-success {
    background-color: #d1fae5;
    color: #065f46;
}

.badge-warning {
    background-color: #fef3c7;
    color: #92400e;
}

.badge-info {
    background-color: #dbeafe;
    color: #1e40af;
}

.hero {
    padding: 80px 0;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero p {
    font-size: 20px;
    margin-bottom: 30px;
}