body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #333;
    color: white;
    padding: 1em;
    text-align: center;
}

header nav ul {
    list-style-type: none;
    padding: 0;
}

header nav ul li {
    display: inline;
    margin: 0 1em;
}

header nav ul li a {
    color: white;
    text-decoration: none;
}

main {
    padding: 2em;
}

form {
    max-width: 300px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
}

form label {
    margin: 0.5em 0 0.2em;
}

form input, form textarea {
    padding: 0.5em;
    margin-bottom: 1em;
}

button {
    padding: 0.7em;
    background-color: #333;
    color: white;
    border: none;
    cursor: pointer;
}

button:hover {
    background-color: #555;
}

#product-list, #cart-list {
    display: flex;
    flex-wrap: wrap;
    gap: 1em;
}

.product, .cart-item {
    border: 1px solid #ccc;
    padding: 1em;
    width: calc(33.333% - 2em);
    box-sizing: border-box;
}

.product button, .cart-item button {
    margin-top: 1em;
}