body {
    font-family: Arial, sans-serif;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    display: flex;
    flex-direction: column;
    font-family: Arial, sans-serif;
}

main {
    flex: 1;
    padding: 1em 20px;
}

header {
    background-color: #4CAF50;
    color: white;
    text-align: center;
    padding: 1em 0;
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1em 0;
}