.box {

  border: 2px solid black;

  padding: 5px;
  margin: 5px;
  height: 500px;
}

.grid-container {
  display: grid;
  grid-template-areas: "col1 col2 col2 col2 col2 col2";
}

#g1 {
  grid-area: col1;
}

#g2 {
  grid-area: col2;
}