body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

.container {
    width: 80%;
    margin: 0 auto;
    overflow: hidden;
}

.header, .footer {
    background: #333;
    color: #fff;
    padding: 10px 0;
    text-align: center;
}

.header h1, .footer p {
    margin: 0;
}

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

.nav ul li {
    display: inline;
    margin-right: 20px;
}

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

.main-content {
    padding: 20px;
    background: #fff;
    margin-top: 20px;
}

.category, .product-detail {
    margin-bottom: 20px;
}

.category h2, .product-detail h2 {
    background: #333;
    color: #fff;
    padding: 10px;
    margin: 0 -20px 20px -20px;
}

.category ul {
    list-style: none;
    padding: 0;
}

.category ul li {
    margin-bottom: 10px;
}

.category ul li a {
    text-decoration: none;
    color: #333;
    padding: 10px;
    background: #e4e4e4;
    display: block;
}

.category ul li a:hover {
    background: #ccc;
}