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

header {
    background-color: #333;
    color: #fff;
    padding: 20px;
    text-align: center;
}

nav {
    background-color: #f2f2f2;
    padding: 10px;
}

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

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

nav ul li a {
    text-decoration: none;
    color: #333;
}

main {
    margin: 20px;
}

section {
    margin-bottom: 20px;
}

h2 {
    border-bottom: 1px solid #333;
    padding-bottom: 10px;
}

article {
    margin-top: 10px;
}

h3 {
    margin-top: 0px;
}

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