body {
    width: 800px;
    margin: 0 auto;
}

#videos {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: 1em;
    width: 100%;
    padding: 10px;
}

video {
    width: 100%;
    border: 2px solid black;
    background-color: greenyellow;
}

textarea {
    height: 50px;
    width: 100%;
}

@media screen and(max-width: 800px) {
    body {
        width: 100%;
    }
}