how to use a blank space with grid template areas css

1.container {
2  display: grid;
3
4  grid-template-columns: 2fr 2fr 1fr 2fr;
5  grid-template-rows: 100px 200px 100px;
6
7  grid-template-areas:
8    "head head . side"
9    "main main . side"
10    "footer footer footer footer";
11}