@import url("https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css");
@import url("https://fonts.googleapis.com/css?family=Roboto:300,400");

/* boton para regresar a la cima de la pagina */
button.back-to-top {
   margin: 0 !important;
   padding: 0 !important;
   background: #fff;
   height: 0px;
   width: 0px;
   overflow: hidden;
   border-radius: 50px;
   -webkit-border-radius: 50px;
   -moz-border-radius: 50px;
   color: transparent;
   clear: both;
   visibility: hidden;
   position: fixed;
   cursor: pointer;
   display: block;
   border: none;
   right: 50px;
   bottom: 75px;
   font-size: 0px;
   outline: 0 !important;
   z-index: 99;
   transition: all .3s ease-in-out;
}

button.back-to-top:hover,
button.back-to-top:active,
button.back-to-top:focus {
   outline: 0 !important;
}

button.back-to-top::before {
   content: "\f077";
   font-family: "FontAwesome";
   display: block;
   vertical-align: middle;
   margin: -5px 0 auto;
}

button.back-to-top.show {
   display: block;
   background: linear-gradient(90deg, #000046 0%, #1cb5e0 100%);
   color: #fff;
   font-size: 25px;
   right: 25px;
   bottom: 50px;
   height: 50px;
   width: 50px;
   visibility: visible;
   box-shadow: 0px 2px 4px 1px rgba(0, 0, 0, 0.25);
   -webkit-box-shadow: 0px 2px 4px 1px rgba(0, 0, 0, 0.25);
   -moz-box-shadow: 0px 2px 4px 1px rgba(0, 0, 0, 0.25);
}

button.back-to-top.show:active {
   box-shadow: 0px 4px 8px 2px rgba(0, 0, 0, 0.25);
   -webkit-box-shadow: 0px 4px 8px 2px rgba(0, 0, 0, 0.25);
   -moz-box-shadow: 0px 4px 8px 2px rgba(0, 0, 0, 0.25);
}