* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'poppins', sans-serif;
  font-size: 65.5%;
}
.container {
  width: 100%;
  height: 100vh;
  background-color: #e3f9ff;
  display: flex;
  justify-content: center;
  align-items: center;
}
.calculator {
  background-color: #3a4452;
  padding: 2rem;
  border-radius: 1rem;
}

.calculator form input {
  border: 0;
  outline: 0;
  width: 6rem;
  height: 6rem;
  border-radius: 1rem;
  box-shadow: -0.8rem -0.8rem 1.5rem rgba(255, 255, 255, 0.1),
    0.5rem 0.5rem 1.5rem rgba(0, 0, 0, 0.2);
  background-color: transparent;
  margin: 1rem;
  color: #fff;
  cursor: pointer;
  font-size: 2rem;
}

form .display {
  display: flex;
  justify-content: flex-end;
  margin: 2rem 0;
}
form .display input {
  text-align: right;
  flex: 1;
  font-size: 4.5rem;
  box-shadow: none;
}
form input.equal {
  width: 14.5rem;
}

form input.operator {
  color: #33ffd8;
}