body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    line-height: 1.6;
    color: #333;
}
header {
    background-color: #f8f8f8;
    border-bottom: 1px solid #ddd;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}
nav ul {
    list-style: none;
    padding: 10px 0;
    margin: 0;
    text-align: center;
}
nav ul li {
    display: inline-block;
    margin: 0 20px;
}
nav ul li a {
    text-decoration: none;
    color: #004aad;
    font-weight: bold;
    font-size: 16px;
}
nav ul li a:hover {
    text-decoration: underline;
}
main {
    max-width: 800px;
    margin: 80px auto 20px;
    padding: 20px;
}
h1, h2 {
    color: #004aad;
}