*
{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.container
{
    display: flex;
    flex-wrap: wrap;
    height: 100vh;
    width: 100%;
    min-height: 100vh;
}

.container .box
{
    position: relative;
    width: 50%;
    height: 50vh;
    filter: grayscale(1);
    border: 4px solid #000;
}

.container .box:hover
{
    filter: grayscale(0);
}

.container .box video
{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}