body {
    margin: 0; 
    padding: 0; 
}

header {
    width: 100%; 
    background: #555; 
    color: white; 
    font-size: 3em; 
    text-align: center; 
}

.container {
    width: 1000px; 
    margin: auto; 
}

menu {
    width: 200px; 
    float: left; 
    background: #ccc; 
    margin: 0; 
    padding: 0; 
    height: 100vw; 
}

menu ul {
    margin: 0; 
    padding: 0; 
}

menu ul li {
    margin: 0; 
    padding: 0;
    list-style-type: none; 
}

menu ul li a {
    text-decoration: none; 
    color: black; 
    font-weight: bold; 
    display: block; 
    border-bottom: 1px solid gray; 
    padding: 5px 15px;    
}
menu ul li a:hover {
    background: #900; 
    color: white; 
    transition: 0.3s;
}

section.extras {
    width: 200px; 
    float: right; 
    font-size: 0.8em; 
    font-family: Arial, Helvetica, sans-serif; 
}

main {
    width: 570px; 
    padding: 0 15px; 
    float: left; 
}

footer {
    clear: both; 
    background: #ccc; 
    width: 100%;
    text-align: center; 

}