main.css

body {
    margin: 40px;
  width:650px;
  height:650px;
    background-color: grey;
}

item-display {
  display: -webkit-flex;
  display: flex;
  flex-direction: row;
    width: 300px;
    height: 250px;
    color: black;
}

#display {
  height:100px;
  width: 235px;
  margin-bottom: 15px;
  font-family: 'Press Start 2P',monospace;
  font-size: 50px;
  text-align: right;
  background-image: url("gokukingSM.png");
  background-repeat: no-repeat;
  background-color: #4d4444;
  color: white;
}

.calc {
  display: -webkit-flex;
  display: flex;
  flex-direction: column;
  align-content: center;
background-color: #e8612a;
width: 240px;
height: 340px;
}

.calculator {
  background-color: grey;
  color: white;
}

.buttons {
  display: -webkit-flex;
  display: flex;
  flex-direction: column;
}

.calRow {
  display: -webkit-flex;
  display: flex;
  flex-direction: row;
  justify-content: space-around;
  margin-bottom: 15px;
}

.box {
  background-color: #3c42b4;
  color: orange;
  border-radius: 5px;
  font-size: 38px;
  font-family: 'Press Start 2P', monospace;
  text-align: center;
}

.operator {
  background-color: orange;
  color: #3c42b4;
  border-radius: 5px;
  font-size: 38px;
  font-family: 'Press Start 2P', monospace;
  text-align: center;
}

.box:hover {background-color: #291A7A}

.box:active {background-color: #3C57B4}

.operator:hover {background-color: #E8872A}

.operator:active {background-color: #E8C22A}

button {border: none}

button:active {
outline: none;
border: none;
}

button:focus {
    outline: none;
}