*{
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}


:root {
  --grid-cols: 1;
  --grid-rows: 1;
}

#container {
  display: grid;
  grid-template-rows: repeat(var(--grid-rows), 1fr);
  grid-template-columns: repeat(var(--grid-cols), 1fr);
  width: 100vw;
  height: 100vh;
}

.grid-item {
  border: none;
  background-color: #ddd;
  text-align: center;
}

.grid-item-invis{
  border: none;
  text-align: center;
  width: 0px;
  height: 0px;
  background-color: #fff;
}