.container{
    width:800px;
    height: 450px;
    border: 5px solid black;
    margin: 50px auto;
    display: grid;
    grid-template-columns: repeat(3,1fr);
    grid-template-rows: repeat(3,1fr);
}

.container div{
    border: 5px solid black;
}
.container div:first-child{background-color: blue;}
.container div:nth-child(2){background-color: blueviolet; grid-row: 1/3;  grid-column: 2/3; }
.container div:nth-child(3){background-color: red;}
.container div:nth-child(4){background-color:orange;}
.container div:nth-child(5){background-color: green;}
.container div:nth-child(6){background-color: olive;}
.container div:nth-child(7){background-color: yellow;}
.container div:nth-child(8){background-color: grey;}