.GridPage {
    display: grid;
    height: 100vh;

    grid-template-columns: repeat(6, 1fr);
    grid-template-rows: 50px 1fr 30px;

    grid-template-areas:
      'header header header header header header'
      'side1 main main main main main'
      'footer footer footer footer footer footer';
  }

  [class^='GridItem'] {
    display: grid;
    align-items: center;
    justify-content: center;
    font-size: 20px;
  }

  .GridItemHeader {
    grid-area: header;
    background-color: var(--color3);
  }

  .GridItemSideBarLeft {
    grid-area: side1;
    background-color: var(--color2);
  }

  .GridItemMain {
    grid-area: main;
  }

  .GridItemFooter {
    grid-area: footer;
    background-color: var(--color2);
  }