#nav
{
    margin: 15px;
    text-align: center;
    }


#nav ul 
{
    overflow: hidden;
    margin: 0;
    padding: 0;

}

#nav ul li 
{
    background-color: #000000;
    color: #55accf;
    border-style: solid;
    border-width: 3px;
    border-color: #00FF00;
    font-family: Monospace;
    font-size: 18px;
    width: 20%; /* fallback for non-calc() browsers */
    width: calc(100% / 5);
    box-sizing: border-box;
    list-style: none;
    float: left;
    text-align: center;
    box-sizing: border-box;
    padding: 2px;
    letter-spacing: 3px;

}


#nav a li:hover
{
    background-color: #00FF00;
    color: black;
}


@media only screen and (max-width: 600px) {
    #container
    {
        margin-left: auto;
        margin-right: auto;
        margin-top: 1em;
        margin-left: 5%;
        margin-right: 5%;
    }
    #nav ul li 
    {
        width: 100%;
        display: solid;
        margin-top: 5px;
        padding: 2px;
    }
}