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

body {
    font-family: "Arial", sans-serif;
    line-height: 1.6;
    color: #333;
}

header {
    background: #1a1a1a;
    color: #fff;
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: #ff6b35;
}

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

nav a {
    color: #fff;
    text-decoration: none;
    transition: color 0.3s;
}

nav a:hover {
    color: #ff6b35;
}

.product_section{
    display: flex;
    gap: 4rem;
    max-width: 1200px;
    margin: 70px auto;
    padding: 4rem 2rem;
}
.product_image {
    flex: 1;
    max-width: 500px;
}

.product_image img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    background-color: #1a1a1a;
}

.product_details {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.product_title {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
}

.product_price {
    font-size: 2rem;
    font-weight: 600;
    color: #22c55e;
}

.product_description {
    font-size: 1.1rem;
    line-height: 1.7;
    color: #a3a3a3;
}

.product_stock {
    font-size: 0.95rem;
    font-weight: 500;
}

.product_stock.in_stock {
    color: #22c55e;
}

.product_stock.out_of_stock {
    color: #ef4444;
}

.add_to_cart_form {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1rem;
    margin-top: 1rem;
}

.add_to_cart_form label {
    font-size: 0.95rem;
    color: #a3a3a3;
}

.quantity_select {
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 1px solid #333;
    border-radius: 4px;
    background-color: #1a1a1a;
    color: #f5f5f5;
    cursor: pointer;
}

.quantity_select:focus {
    outline: none;
    border-color: #f5f5f5;
}

.add_to_cart_btn {
    padding: 1rem 2.5rem;
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border: none;
    border-radius: 4px;
    color: #f5f5f5;
    background-color: #0a0a0a;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s ease;
}

.add_to_cart_btn:hover:not(:disabled) {
    background-color: #ff6b35;
}

.add_to_cart_btn:disabled {
    background-color: gray;
    color: white;
    cursor: not-allowed;
}

.back_link {
    display: inline-block;
    margin-top: 1rem;
    font-size: 0.95rem;
    color: #a3a3a3;
    text-decoration: none;
    transition: color 0.2s ease;
}

.back_link:hover {
    color: #f5f5f5;
}

@media (max-width: 768px) {
    .product_section {
        flex-direction: column;
        gap: 2rem;
        padding: 2rem 1rem;
    }

    .product_image {
        max-width: 100%;
    }

    .product_title {
        font-size: 1.75rem;
    }

    .product_price {
        font-size: 1.5rem;
    }

    .add_to_cart_form {
        flex-direction: column;
        align-items: stretch;
    }

    .add_to_cart_btn {
        width: 100%;
    }
}