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

  button {
    border: none;
    color: white;
  }

  .container-fluid {
    background-color: black;
    overflow: hidden;
    border-radius: 50px;
  }

  .calculator {
    background-color: black;
    width: 16em;
    margin: 2em auto;
  }

  .calculatorDisplay {
    background-color: black;
    color: white;
    text-align: right;
    padding-right: 0.5em;
    padding-top: 0.25em;
    margin-bottom: 0.25em;
    font-size: 2.5em;
    border: none;
    width: 100%;
  }

  .calculatorKeys {
    background-color: transparent;
    display: grid;
    grid-gap: 1px;
    height: 20em;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(5, 1fr);
    align-content: space-between;
    gap: 10px;
  }

  button:hover {
    opacity: 0.9;
  }

  button:active {
    opacity: 0.7;
  }

  .calculatorKeys > * {
    padding: 0.5em 1.25em;
    position: relative;
    text-align: center;
    z-index: 1;
  }

  .is-depressed::before {
    background-color: red;
    bottom: 0;
    content: "";
    left: 0;
    opacity: 0.3;
    position: absolute;
    right: 0;
    top: 0;
    z-index: -1;
    border-radius: 4500px;
  }

  .grayKey {
    background-color: WhiteSmoke;
    border-radius: 50%;
    color: black;
  }

  .numberKey{
    background-color: DimGray;
    border-radius: 50%;
  }

  .operatorKey {
    background-color: orange;
    border: none;
    border-radius: 50%;
  }

  .ACKey {
   grid-column: 1 / span 3;
   grid-row: 1;
   border-radius: 4500px;
  }

  .zeroKey {
    grid-column: 1 / span 2;
    grid-row: 5;
    border-radius: 4500px;
  }