Labo4

.grid-container {
  display: grid;
  grid-template-columns: 50fr 50fr;
  grid-template-rows: 35fr 35fr 35fr;
  
  grid-template-areas:
    "header header"
    "sidebar main-content"
    "footer footer"
}

.header {
  grid-area: header;
}

.sidebar {
  grid-area: sidebar;
}

.main-content {
  grid-area: main-content;
}

.footer {
  grid-area: footer;
}