button {
    margin: 0 3px 10px 0;
    padding-left: 2px;
    padding-right: 2px;
    width: 99px;
    font-size: 12px;
}

#test{
    display: none;
}

#buttonDiv{
    margin-top: 50px;
}

button:last-of-type {
    margin: 0;
}

p.borderBelow {
    margin: 0 0 20px 0;
    padding: 0 0 20px 0;
}

video {
    height: 232px;
    margin: 0 12px 20px 0;
    vertical-align: top;
    width: calc(20em - 10px);
}


video:last-of-type {
    margin: 0 0 20px 0;
    background: #222;
}

@media screen and (max-width: 500px) {
    button {
        font-size: 0.8em;
        width: calc(33% - 5px);
    }
}

@media screen and (max-width: 720px) {
    video {
        height: calc((50vw - 48px) * 3 / 4);
        margin: 0 10px 10px 0;
        width: calc(50vw - 48px);
    }
}