.grids, .result {
  margin: 5px;
  display: inline-flex;
}

.grid {
  display: grid;
  text-align: center;
  border: 1px solid #000;
  padding: 5px 2px;
}

.sign {
  background: #BBF;
}

.exp {
  background: #BFB;
}

.frac {
  background: #FBB;
}