body{
    font-family: Arial, sans-serif;
    margin:0;
    background:#f4f4f4;
}

header{
    background:green;
    color:white;
    text-align:center;
    padding:20px;
}

nav{
    background:#333;
    text-align:center;
    padding:10px;
}

nav a{
    color:white;
    text-decoration:none;
    margin:15px;
}

main{
    background:white;
    width:80%;
    margin:20px auto;
    padding:20px;
}

footer{
    background:green;
    color:white;
    text-align:center;
    padding:15px;
}