:root {
    --primary-color: #007BFF;
    --secondary-color: #6C757D;
    --background-color: #F8F9FA;
    --surface-color: #FFFFFF;
    --accent-color: #FFC107;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
}

.navbar {
    background: linear-gradient(90deg, var(--primary-color), #0056b3);
}

.category-tabs .nav-link {
    color: var(--secondary-color);
    border: 1px solid transparent;
}

.category-tabs .nav-link.active {
    color: var(--primary-color);
    border-bottom: 2px solid var(--primary-color);
    background-color: transparent;
}

.product-card {
    border-radius: 0.5rem;
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
    border: 1px solid #dee2e6;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.product-card img {
    border-top-left-radius: 0.5rem;
    border-top-right-radius: 0.5rem;
    aspect-ratio: 4 / 3;
    object-fit: cover;
}

.product-price {
    color: var(--primary-color);
    font-weight: bold;
}

.loader {
    border: 4px solid #f3f3f3;
    border-radius: 50%;
    border-top: 4px solid var(--primary-color);
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
}

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