:root {
    --primary-color: #2563eb;
    --secondary-color: #1d4ed8;
    --background-color: #f8fafc;
    --text-color: #1e293b;
    --card-background: #ffffff;
    --border-color: #e2e8f0;
}

body {
    font-family: 'Inter', 'Segoe UI', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    -webkit-tap-highlight-color: transparent;
}

header {
    background-color: var(--card-background);
    color: var(--text-color);
    padding: 0.75rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

@media (min-width: 768px) {
    header {
        padding: 1rem 2rem;
    }
}

header h1 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

@media (min-width: 768px) {
    header h1 {
        font-size: 1.5rem;
    }
}

.cart-icon {
    position: relative;
    color: var(--text-color);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color 0.3s ease;
    padding: 0.5rem;
    margin: -0.5rem;
}

.cart-icon:hover {
    color: var(--primary-color);
}

.cart-count {
    position: absolute;
    top: -5px;
    right: -5px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    padding: 3px 6px;
    font-size: 0.75rem;
    font-weight: 600;
}

.filters {
    display: flex;
    gap: 0.5rem;
    margin: 1rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.filters::-webkit-scrollbar {
    display: none;
}

@media (min-width: 768px) {
    .filters {
        gap: 1rem;
        margin: 2rem;
        flex-wrap: wrap;
        overflow-x: visible;
    }
}

.filter-button {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--card-background);
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
    font-size: 0.9rem;
    -webkit-tap-highlight-color: transparent;
}

.filter-button:hover,
.filter-button.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

main {
    display: flex;
    flex-direction: column;
    padding: 0 1rem 1rem;
    max-width: 1400px;
    margin: 0 auto;
    gap: 1rem;
}

@media (min-width: 768px) {
    main {
        flex-direction: row;
        padding: 0 2rem 2rem;
        gap: 2rem;
    }
}

.products {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 1rem;
}

@media (min-width: 480px) {
    .products {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}

@media (min-width: 768px) {
    .products {
        flex: 2;
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 2rem;
    }
}

.product-item {
    background-color: var(--card-background);
    border-radius: 12px;
    padding: 0.75rem;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

@media (min-width: 768px) {
    .product-item {
        padding: 1rem;
    }

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

.product-item img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 0.75rem;
}

@media (min-width: 768px) {
    .product-item img {
        height: 200px;
        margin-bottom: 1rem;
    }
}

.product-item h3 {
    margin: 0.5rem 0;
    font-size: 1rem;
    color: var(--text-color);
}

.product-item .price {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 1.1rem;
    margin: 0.5rem 0;
}

.product-item button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem;
    font-size: 0.9rem;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    width: 100%;
    font-weight: 500;
    -webkit-tap-highlight-color: transparent;
}

.product-item button:hover {
    background-color: var(--secondary-color);
}

.cart {
    background-color: var(--card-background);
    border-radius: 12px;
    padding: 1rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border-color);
    margin-bottom: 4rem;
}

@media (min-width: 768px) {
    .cart {
        flex: 1;
        position: sticky;
        top: 100px;
        max-height: calc(100vh - 140px);
        overflow-y: auto;
        padding: 1.5rem;
        margin-bottom: 0;
    }
}

.cart h2 {
    margin-top: 0;
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--text-color);
}

@media (min-width: 768px) {
    .cart h2 {
        font-size: 1.25rem;
        margin-bottom: 1.5rem;
    }
}

.cart-items {
    list-style: none;
    padding: 0;
    margin: 0;
}

.cart-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    gap: 0.5rem;
}

@media (min-width: 768px) {
    .cart-item {
        padding: 1rem 0;
        gap: 1rem;
    }
}

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

.cart-item img {
    width: 50px;
    height: 50px;
    object-fit: cover;
    border-radius: 6px;
}

@media (min-width: 768px) {
    .cart-item img {
        width: 60px;
        height: 60px;
    }
}

.cart-item-info {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    min-width: 0;
}

.cart-item-name {
    font-weight: 500;
    color: var(--text-color);
    font-size: 0.9rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.cart-item-price {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 0.9rem;
}

@media (min-width: 768px) {
    .cart-item-name,
    .cart-item-price {
        font-size: 1rem;
    }
}

.quantity-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.quantity-btn {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-color);
    transition: all 0.3s ease;
    -webkit-tap-highlight-color: transparent;
}

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

.quantity {
    font-weight: 500;
    min-width: 24px;
    text-align: center;
    font-size: 0.9rem;
}

.cart-total {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

@media (min-width: 768px) {
    .cart-total {
        margin-top: 1.5rem;
        padding-top: 1.5rem;
        gap: 1rem;
    }
}

.total-row {
    display: flex;
    justify-content: space-between;
    font-weight: 500;
    font-size: 0.9rem;
}

@media (min-width: 768px) {
    .total-row {
        font-size: 1rem;
    }
}

.checkout-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
    width: 100%;
    margin-top: 1rem;
    font-size: 1rem;
    -webkit-tap-highlight-color: transparent;
}

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

footer {
    text-align: center;
    padding: 1.5rem 1rem;
    background-color: var(--card-background);
    color: var(--text-color);
    border-top: 1px solid var(--border-color);
    font-size: 0.9rem;
}

@media (min-width: 768px) {
    footer {
        padding: 2rem;
        font-size: 1rem;
    }
}

/* Animations */
@keyframes slideIn {
    from {
        transform: translateX(100%);
    }
    to {
        transform: translateX(0);
    }
}

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

.product-item {
    animation: fadeIn 0.5s ease;
}