body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
nav.main-menu {
    background-color: #333;
    color: white;
    padding: 10px;
}
nav.main-menu ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
}
nav.main-menu ul li {
    display: inline-block;
    margin-right: 10px;
}
nav.main-menu ul li a {
    color: white;
    text-decoration: none;
    padding: 8px;
}
.contact-section, .about-section, .product-list {
    padding: 20px;
}
.contact-section input, .contact-section textarea {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
}
.contact-section button {
    background-color: #4CAF50;
    color: white;
    padding: 10px 20px;
    border: none;
    cursor: pointer;
}