calculatorStyle.css

.container {
  text-align:center;
}

.calculator {
  background-color: grey;
  height: 250px;
  width: 250px;
  display: inline-block;
  border-radius: 13px;
  box-shadow: 2px 2px 2px green;
}

.readout {
  background-color:white;
  height: 40px;
  width: 220px;
  display: inline-block;
  margin-top: 10px;
  border-radius: 10px;
  box-shadow: 1px 1px 1px black;
  
}

.readout .readoutText {
  position:relative;
  bottom: 0;
  text-align: right;
  padding-right: 3px;
  color: grey;
  
}

td {
  border: 2px solid black;
  border-radius: 3px;
  width: 50px;
  background-color: #e3ff67;
  box-shadow: 1px 1px 1px black;
  
}

td:hover {
  background-color: #e3ff15;
}

td:active {
  border: 2px solid blue;
  box-shadow: 0px 0px 0px black;
}

tr {
  width: 100%;
}

table {
  margin: 20px;
}