body {
    font-family: "open sans", "sans-sserif";
    background-image: linear-gradient(to top, #fbc2eb 0%, #a6c1ee 100%, #E0C3FC 100%);
  }
  
  #container {
    height: 100vh;
    background-image: linear-gradient(to top, #fbc2eb 0%, #a6c1ee 100%, #E0C3FC 100%);
    display: flex;
    align-items: start;
    justify-content: center;
  }
  
  #calculator {
    width: 320px;
    height: 520px;
    background-color: #eaedef;
    border-radius: 5px;
    box-shadow: 0 4px 9px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0;
  }
  
  #result {
    height: 120px;
  }
  
  #history {
    text-align: right;
    height: 20px;
    margin: 0 20px;
    padding-top: 20px;
    font-size: 110%;
    color: black;
  }
  
  #output {
    text-align: right;
    font-size: 200%;
    font-weight: bold;
    height: 60px;
    margin: 10px 20px;
  }
  #keyboard {
    height: 400px;
  }
  
  .operator,
  .number,
  .empty {
    width: 50px;
    height: 50px;
    margin: 15px;
    float: left;
    border-radius: 50%;
    border-width: 0;
    font-size: 110%;
    font-weight: bold;
  }
  
  .number,
  .empty {
    background-color: #eaedef;
  }
  
  .number,
  .operator {
    cursor: pointer;
  }
  
  .operator:active,
  .number:active {
    font-size: 140%;
  }
  
  .operator:focus,
  .number:focus,
  .empty:focus {
    outline: 0;
  }
  
  button:nth-child(4) {
    font-size: 130%;
    background-color: pink;
  }
  
  button:nth-child(8) {
    font-size: 130%;
    background-color: rgb(233, 233, 97);
  }
  
  button:nth-child(12) {
    font-size: 130%;
    background-color: rgb(163, 252, 30);
  }
  
  button:nth-child(16) {
    font-size: 130%;
    background-color: rgb(206, 145, 206);
  }
  
  button:nth-child(20) {
    font-size: 130%;
    background-color: rgb(100, 176, 226);
  }
  

  @media (max-width: 700px) {
    body, #container {
      background: #000;
    }
    #calculator {
      background: #000;
    }
    #result {
      color: #fff;
    }
    #history {
      font-size: 1.8rem;
      color: #fff;
    }

  }


  @media (min-width: 414px) {
    body, #container {
      background: #000;
    }
    #calculator {
      background: #000;
    }
    #result {
      color: #fff;
      margin: 5px 0;
      font-size: 1.5rem;
      padding-bottom: 3rem;
    }
    #history {
      font-size: 1.5rem;
      padding-bottom:1rem;
      margin: 5px 0;
      color: #fff;
    }
  .operator,
  .number,
  .empty {
    width: 65px;
    height: 65px;
    margin:15px 7px;
    border-radius: 50%;
    font-size: 1.3rem;
  }

  }