* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f5f5;
    color: #333;
}

.navbar {
    background: #2c3e50;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
}

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

.nav-links a {
    color: white;
    text-decoration: none;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #3498db;
}

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 4rem 2rem;
}

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

.products, .cart, .payment {
    padding: 3rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.products h2, .cart h2, .payment h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: #2c3e50;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.product-card {
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.product-card:hover {
    transform: translateY(-5px);
}

.product-card img {
    width: 100%;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.product-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.product-card .price {
    color: #e74c3c;
    font-size: 1.2rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.product-card .specs {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.product-card button {
    width: 100%;
    padding: 0.8rem;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s;
}

.product-card button:hover {
    background: #2980b9;
}

.cart-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: white;
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 8px;
}

.cart-item button {
    padding: 0.5rem 1rem;
    background: #e74c3c;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

.cart-total {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    text-align: right;
}

.cart-total p {
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

.cart-total button {
    padding: 0.8rem 2rem;
    background: #27ae60;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
}

.payment-methods {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.payment-option {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: white;
    border-radius: 8px;
    cursor: pointer;
}

.payment-option input {
    width: 20px;
    height: 20px;
}

#paymentDetails {
    margin-bottom: 2rem;
}

#paymentForm button {
    width: 100%;
    padding: 1rem;
    background: #27ae60;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1rem;
}

footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
}