@import url('https://fonts.googleapis.com/css2?family=M+PLUS+Rounded+1c:wght@100;300;400;500;700&display=swap');

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    background-color: #E7EAF2;
    height: 700px;
    font-family: 'M PLUS Rounded 1c', sans-serif;
    font-size: 28px;
  }
  
  .calculator {
    text-align: center;
    height: 100%;
    margin: 0 auto;
    max-width: 400px;
    background-color: #F2F3F7;
    -webkit-box-shadow: -5px -5px 15px rgba(255, 255, 255, 0.8),
      5px 5px 10px rgba(0, 0, 0, 0.1);
    box-shadow: -5px -5px 15px rgba(255, 255, 255, 0.8),
      5px 5px 10px rgba(0, 0, 0, 0.1);
    border-radius: 20px;
    margin-top: 100px;
  }
  
  .output {
    overflow: hidden;
    color: #3B80FD;
    font-size: 48pt;
    height: 15%;
    padding: 10px;
    text-align: right;
    border-radius: 20px;
    -webkit-box-shadow: inset -5px -5px 15px rgba(255, 255, 255, 0.8),
      inset 5px 5px 10px rgba(0, 0, 0, 0.1);
    box-shadow: inset -5px -5px 15px rgba(255, 255, 255, 0.8),
      inset 5px 5px 10px rgba(0, 0, 0, 0.1);
    border: 0 none;
    background: #e9effb;
    margin-bottom: 20px;
    width: 390px;
    margin-left: auto;
    margin-right: auto;
    font-weight: 300;
  }
  
  .button {
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
    cursor: pointer;
    float: left;
    padding: 5%;
    -webkit-transition: 0.5s;
    transition: 0.5s;
    width: 80px;
    margin: 10px;
    color: #202847;
    border-radius: 20px;
    -webkit-box-shadow: -5px -5px 15px rgba(255, 255, 255, 0.8),
      5px 5px 10px rgba(0, 0, 0, 0.1);
    box-shadow: -5px -5px 15px rgba(255, 255, 255, 0.8),
      5px 5px 10px rgba(0, 0, 0, 0.1);
    border: 0 none;
    background: #F2F3F7;
    height: 80px;
    font-weight: 300;
  }
  
  .button:active {
    -webkit-box-shadow: inset -5px -5px 15px rgba(255, 255, 255, 0.8),
      inset 5px 5px 10px rgba(0, 0, 0, 0.1);
    box-shadow: inset -5px -5px 15px rgba(255, 255, 255, 0.8),
      inset 5px 5px 10px rgba(0, 0, 0, 0.1);
    color: #3B80FD;
  }

  .operation{
      background: #3B80FD;
      color: #fff;
  }
  
  .double {
    width: 70%;
  }
  
  @media only screen and (max-width: 450px) {
    .calculator {
      width: 350px;
      font-size: 25px;
      height: 600px;
    }
    .button {
      width: 60px;
      height: 60px;
    }
  
    .output {
      width: 350px;
      height: 100px;
    }
  }