#grid-left {
    float: left;
    height:75vh;
    width: 49%;
}

#grid-right {
    float: right;
    margin-right: 1vh;
    height: 75vh;
    width: 49%;
}

@media only screen and (max-width: 800px) {
    #grid-left {
        width: 100%;
    }

    #grid-right {
        width: 100%;
    }
}