.cuadro-mondrian {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr; 
    grid-template-rows: 1fr 1fr ; 
    grid-gap: 0px; 
    width: 400px; 
    margin: 0 auto;
}

.elemento {
    height: 100px; 
    border: 4px solid black; 
}

.elemento1 {
    background-color: red;
    grid-column-start: 1;
    grid-column-end: 1;
    grid-row-start: 2;
    grid-row-end: 2;
}

.elemento2 {
    background-color: yellow;
    grid-column-start: 2;
    grid-column-end: 3;
    grid-row-start: 2;
    grid-row-end: 3;
}

.elemento3 {
    background-color: blue;
    grid-column-start: 4;
    grid-column-end: 3;
    grid-row-start: 1;
    grid-row-end: 3;
}

.elemento4 {
    background-color: white;
    grid-column-start: 1;
    grid-column-end: 3;
    grid-row-start: 1;
    grid-row-end: 3;
}