.BodyHorizontalUpperGrow { display: grid; grid-template-areas: "upper" "lower" "error"; grid-template-rows: 1fr auto auto; } .Upper { grid-area: upper; } .Upper > * { width: 100%; height: 100%; } .Lower { grid-area: lower; margin-top: 10px; } .Lower > * { width: 100%; height: 100%; } .Error { grid-area: error; margin-top: 10px; }