body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background-color: #f0f0f0;
}

.calculator {
  height: 600px;
  width: 400px;
  background-color: #fff;
  border-radius: 5px;
  padding: 20px;
  box-shadow: 0px 0px 10px 0px rgba(0,0,0,0.1);
}

.calculator-screen {
  width: 100%;
  height: 100px;
  text-align: right;
  border: none;
  margin-bottom: 20px;
  font-size: 2em;
}

button {
  height: 50px;
  width: 120px;
  background-color: #f2f2f2;
  border: none;
  font-size: 2.5em;
  margin: 5px;
  outline: none;
}

.operator, .equal-sign {
  background-color: #fe9241;
  color: #fff;
}
.equal-sign{
  width: 254px;
}

.operator:hover, .equal-sign:hover {
  background-color: #ffab62;
}

.button:hover {
  background-color: #e0e0e0;
}