body {
  display: flex;
  justify-content: center;
  align-items: center;
  background-image: url(background.jpg);
  height: 100vh;
  width: 100vw;
}
.container {
  background-color: black;
  width: 500px;
  border-radius: 20px;
  border: 3px solid gold;
  box-shadow: 2px 2px 16px 4px rgb(226, 103, 58);
}

#calculator {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  padding: 30px;
}
button {
  border-radius: 50px;
  border: none;
  width: 100px;
  height: 100px;
  font-size: 3rem;
  font-weight: bold;
  color: white;
  background-color: hsl(0, 0%, 45%);
  cursor: pointer;

  &:hover {
    background-color: hsl(0, 0%, 55%);
  }

  &:active {
    background-color: hsl(0, 0%, 75%);
    box-shadow: 1px 1px 16px white;
  }
}
#display {
  width: 460px;
  font-size: 5rem;
  background-color: hsl(0, 0%, 5%);
  border-radius: 30px;
  margin-left: 20px;
  margin-top: 20px;
  box-shadow: 2px 2px 16px white;
  color: white;
}
.operator {
  background-color: orange;

  &:hover {
    background-color: hsl(39, 100%, 60%);
  }
  &:active {
    background-color: hsl(39, 100%, 80%);
  }
}