@charset 'utf-8';
.container{
    display: grid;
    grid-template-columns:100px 1fr 100px;
    grid-template-rows: 100px 1fr 200px;
    gap: 10px;
    border: 1px solid;
    height: 500px;
}
.item{
    background:#0bd;
    color:#fff;
    padding:10px;
}