.cabecera {
  grid-area: cab; 
    background-color: antiquewhite
}
.principal {
  grid-area: prin;  
    background-color: aliceblue
}
.lateral {
  grid-area: lat; 
    background-color: aquamarine
}
.pie {
  grid-area: pie;  
    background-color: beige
} 

.grid {
  
display: grid;
    grid-template-columns: 1fr 2fr 1fr;
    grid-template-rows: 100px 200px 100px 50px;
    grid-template-areas: 
        "cab  cab ."
        "prin prin lat"
        "prin prin lat"
        "pie pie lat";
}