button#backToTop, button#backToTop:link, button#backToTop:visited, button#backToTop:active{
    background:var(--colorB1);
    color:#fff;
    border:none;
    width:48px;
    height:48px;
    font-size:1.2em;
    cursor:pointer;
    outline:none;
    position: fixed;
    left: 10px;
    bottom: 20px;
    display: flex;
    opacity: 0;
    visibility: hidden;
    z-index:2000;
    text-align:center;
    background-image:url(/img/Arriba.png);
    background-repeat:no-repeat;
    background-position:0 0;
    border-radius: 16px;
    -moz-border-radius: 16px;
    -webkit-border-radius: 16px;
              -webkit-box-shadow: -1px -7px 22px -5px rgba(0,0,0,0.46);
  -moz-box-shadow: -1px -7px 22px -5px rgba(0,0,0,0.46);
  box-shadow: -1px -7px 22px -5px rgba(0,0,0,0.46);
  transition: all 0.5s ease;
	-webkit-transition: all 0.5s ease;
	-moz-transition: all 0.5s ease;
	-o-transition: all 0.5s ease;
  }
  .goToA{
      position: absolute;
      bottom: 17px;
      left:65px;
      width:84px;
      height: 23px;
      padding:0;
      padding-top:2px;
      margin:0 auto;
      font-size:1.1rem;
      text-align:center;
      line-height:100%;
      display:block;
      background-color: var(--colorB1);
      color:#FFFFFF;
      border-radius: 5px 5px 5px 5px;
      -moz-border-radius: 5px 5px 5px 5px;
      -webkit-border-radius:5px 5px 5px 5px;
      -webkit-box-shadow: -1px -7px 22px -5px rgba(0,0,0,0.46);
  -moz-box-shadow: -1px -7px 22px -5px rgba(0,0,0,0.46);
  box-shadow: -1px -7px 22px -5px rgba(0,0,0,0.46);
  transition: all 0.5s ease;
	-webkit-transition: all 0.5s ease;
	-moz-transition: all 0.5s ease;
	-o-transition: all 0.5s ease;
  }	
  
  .goToA:after{
      content: '';
      position:absolute;
      display:block;
      bottom:5px;
      left:-8px;
       width: 0;
      height: 0;
      border-top: 5px solid transparent;
      border-right: 10px solid var(--colorB1);
      border-bottom: 5px solid transparent;
      transition: all 0.5s ease;
      -webkit-transition: all 0.5s ease;
      -moz-transition: all 0.5s ease;
      -o-transition: all 0.5s ease;
  }
  button#backToTop:hover{
    background:var(--colorB2);
    background-image:url(/img/Arriba.png);
    background-repeat:no-repeat;
    background-position:0 0;
  }
  button#backToTop:hover .goToA{
    background:var(--colorB2);
  }
  button#backToTop:hover .goToA:after{
    border-top: 5px solid transparent;
    border-right: 10px solid var(--colorB2);;
    border-bottom: 5px solid transparent;
  }