css grids grid-area code example

Example: unknown property grid-template-areas

.sidebar{
    	grid-area:sidebar;
      background:aqua;

    }
    .grid_container{
    	display:grid;
    	grid-template-columns: 1fr 3fr;
      grid-template-rows: 1fr 3fr;
    	grid-template-areas:
    	"sidebar ."
    	"sidebar .";
      background:pink;
      height:300px;
    }