#container{
    width: 1500px;
    height: 250px;
}

.witkey{
    border: 1px solid black;
    width: 60px;
    height: 250px;
    position: relative;
    float: left;
    z-index: 1;
}

.zwartkey1 {
    border: 1px solid black;
    width: 40px;
    height: 150px;
    position: absolute;
    float: left;
    z-index: 2;
    background-color: black;
}

.tekst {
    justify-content: center;
    position: relative;
    display: flex;
    top: 90%;
}