* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    background-color: #f4f4f4;
    color: #333;
}

header {
    background-color: #1f2933;
    padding: 15px 0;
}

nav {
    max-width: 900px;
    margin: auto;
    display: flex;
    justify-content: space-around;
}

nav a {
    color: #ffffff;
    text-decoration: none;
    font-weight: bold;
}

nav a:hover {
    text-decoration: underline;
}

main {
    max-width: 900px;
    margin: 40px auto;
    background-color: #ffffff;
    padding: 25px;
    border-radius: 5px;
}

footer {
    text-align: center;
    padding: 15px;
    background-color: #e5e7eb;
    margin-top: 40px;
    font-size: 0.9em;
}