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

header {
    background-color: #333;
    color: #fff;
    padding: 10px 20px;
}

header h1 {
    margin: 0;
}

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

nav ul li {
    display: inline;
    margin-right: 10px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
}

main {
    padding: 20px;
}

footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 10px 0;
    position: absolute;
    bottom: 0;
    width: 100%;
}

.intro, .about, .products, .contact {
    margin: 20px 0;
}

.product-list {
    display: flex;
    justify-content: space-around;
}

.product-item {
    border: 1px solid #ccc;
    padding: 10px;
    margin: 10px;
    width: 30%;
}