body::before {
    content: "XS";
    color: #c8372f;
    font-size: 2rem;
    font-weight: bold;
    position: fixed;
    bottom: 0;
    right: 0;
    margin-bottom: 30px;
    margin-right: 30px;
    background-color: #F9F8F5;
    border: 1px solid #dee2e6;
    padding:15px;
    border-radius: 40px;
    z-index: 10000;
  }
  
  .box {
    background-color: lightblue;
    border: 1px solid blue;
    min-height: 50px;
    font-size: 2rem;
    
  }
  
  @media (min-width: 576px) {
    body::before {
      content: "SM";
    }
  }
  
  @media (min-width: 768px) {
    body::before {
      content: "MD";
    }
  }
  
  @media (min-width: 992px) {
    body::before {
      content: "LG";
    }
  }
  
  @media (min-width: 1200px) {
    body::before {
      content: "XL";
    }
  }
  
  @media (min-width: 1400px) {
    body::before {
      content: "XXL";
    }
  }