.oefening {
    cursor: pointer;
    background-color: #fff;
    text-align: left;
    font-size: 5vw;
    padding: 0vw 0vw 0vw 2vw;
    }
.oplossing {
    display: none;
    }
.geluid {
    width: 50vw;
    margin-top: 1vw;
    margin-bottom: 1vw;
    margin-left: auto;
    margin-right: auto;
    padding: 1vw;
    background-color: #eee;
    border: 2px solid #fff;
    }
.geluid:hover {
    background-color: #fff;
    border: 2px solid #fb2;
    }
@media only screen and (orientation: landscape) {
.oefening {
    cursor: pointer;
    width: 100%;
    background-color: #fff;
    text-align: left;
    font-size: 3.4vw;
    padding: 0vw 0vw 0vw 2vw;
    }
}

@media only screen and (orientation: landscape) and (min-width: 750px) {
.geluid {
    width: 40vw;
    margin-top: 0vw;
    margin-bottom: 0vw;
    margin-left: auto;
    margin-right: auto;
    padding: 1vw;
    font-size: 2.7vw;
    background-color: #eee;
    border: 2px solid #fff;
    }
}