Body {
    background-color: #f5f5f5;
}
main {
    margin: 60px 30px 30px 30px;
    color: green
}

img:hover {
    border: 5px solid green
}

nav {
    background-color: white;
    height: 30px;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;

    border-bottom: 1px solid black;
    
    text-align: center;
}

nav {
    padding-top: 10px;
}
nav a {
    color: darkgray;
    text-decoration: none;
}

nav a:hover {
    color: black;
}

nav a.active {
    color: black;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

nav ul li {
    margin: 2px;
    display: inline-block;
    width:100px;
    height: 20px;
    background-color: rgb(227, 227, 227);
    padding: 3px;
}


main ul.blokjes {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

main ul.blokjes li {
    background-color: rgb(57, 120, 221);
    margin: 2px;
    display: inline-block;
    width:200px;
    height: 120px;
}