body {
    position: absolute;
    width: 100%;
    height: 100%;
    margin: 0px;
    padding: 0px;
}

.parent {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    grid-template-rows: repeat(5, 1fr);
    grid-column-gap: 0px;
    grid-row-gap: 0px;
    background-color: rgba(100,100,100,0.2);
}
    
.div1 {
    grid-area: 1 / 1 / 3 / 2;
    background-color: rgba(255,0,0,0.2);
}

.div2 {
    grid-area: 3 / 1 / 6 / 2;
    background-color: rgba(0,255,0,0.2);
}

.div3 {
    grid-area: 1 / 2 / 2 / 6;
    background-color: rgba(255,0,255,0.2);
}

.div4 {
    grid-area: 2 / 2 / 6 / 6;
    background-color: rgba(0,255,255,0.2);
}