body {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-gap: 10px;
    grid-auto-rows: minmax(50px, auto);
}

header {
    grid-column: 1 / 3;
    grid-row: 1;
}

aside {
    grid-column: 1;
    grid-row: 2;
}

main {
    grid-column: 2 /3;
    grid-row: 2