fr css grid code example

Example 1: css grid

.item-a {
  grid-area: header;
}
.item-b {
  grid-area: main;
}
.item-c {
  grid-area: sidebar;
}
.item-d {
  grid-area: footer;
}

.container {
  display: grid;
  grid-template-columns: 50px 50px 50px 50px;
  grid-template-rows: auto;
  grid-template-areas: 
    "header header header header"
    "main main . sidebar"
    "footer footer footer footer";
}

Example 2: what are the units used in css grid

the units used in css grid are as follows:
  1) fr: sets the column or row to a fraction of the available space.
  2) auto: sets the column or row to the width or height of its content 
            automatically.
  3) %: sets the column or row to the percent width  of its container.