.calculator {
  width: 30%;
  margin: 0 auto;
  padding: 2%;
  background-color: #ffefd5;
  border-radius: 10px;
  box-shadow: 5px 5px 5px;
}

.display input {
background-color: #000000;
font-size: 280%;
width: 90%;
color: #3CB371;
font-family: "SevenSegment";
}

.display {
  width: 90%;
  height: 20%;
  margin-bottom: 5%;
  padding: 1%;
  background-color: #000000;
  border: 2px solid #ffff00;
  border-radius: 5px;
  font-size: 100%;
  text-align: center;
}

.keys {
  display: inline-block;
  width: 90%;
  height: 60%;
  margin: 1%;
  padding: 1%;
  background-color: #f0e68c;
  border: 1px solid #ffff00;
  border-radius: 5px;
  font-size: 60%;
  text-align: center;
  cursor: pointer;
}

.button {
  width: 20%;
  height: 20%;
  margin: 2%;
  font-size: 150%;
  padding: 5%;
  box-shadow: 1px 1px 1px black;
}

.button.black {
  background-color: #000000;
  color: #ffffff;
}

.button.blue {
  background-color: #6495ed;
  color: #ffffff;
}

.button.red {
  background-color: #b22222;
  color: #ffffff;
}

@font-face {
  font-family: "SevenSegment";
  src: url("SevenSegment.ttf") format("truetype");
  
  font-weight: normal;
}