html {
    background: url("../img/NuEvenNiet.JPG") no-repeat center center fixed; 
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

a {
    color: black;
}

h1 {
    color: black;
}

#header {
    width: 100%;
    height: 50px;
    text-align: center
}

#KolomRechts {
    width: 100%;
    float: left;
    padding: 20px;
}

.container {
    width: 100%;
}
nav, section {
    float: left; 
    padding: 20px;
    min-height: 170px;
    box-sizing: border-box;
}
section {
    width: 80%;
}
nav {
    width: 10%;
}