#btn-scroll-down {
    border-width: 0; 
    position: fixed;
    right: 2px;
    z-index: 99;
    -webkit-transition-duration: 0.3s;
    transition-duration: 0.3s;
    opacity: 0;
    filter: alpha(opacity=0);
    bottom: -24px;
    visibility: hidden;
  }
  #btn-scroll-down.display {
    opacity: 0.7;
    filter: alpha(opacity=70);
    bottom: 2px;
    visibility: visible;
  }
  #btn-scroll-down:hover {
    opacity: 1;
    filter: alpha(opacity=100);
  }
  #btn-scroll-down:focus {
    outline: none;
  }
  @media (min-width: 768px) {
    .main-container.container > #btn-scroll-down {
        right: auto;
        margin-left: 714px;
    }
  }
  @media (min-width: 992px) {
    .main-container.container > #btn-scroll-down {
        right: auto;
        margin-left: 934px;
    }
  }
  @media (min-width: 1200px) {
    .main-container.container > #btn-scroll-down {
        right: auto;
        margin-left: 1134px;
    }
  }