.slow .toggle-group {
    transition: left 0.7s;
    -webkit-transition: left 0.7s;
}
#preview img {
    width: 15rem;
    height: 15rem;
}

/* ESTILO DEL TAB */
.nav-tabs{
   
}
.nav-tabs > li > a{
    color:black;
    background-color: white;
}
.nav-tabs > li > a:hover{
    border: medium none;
    border-radius: 0;
}
.nav-tabs>li.active>a, .nav-tabs>li.active>a:focus, .nav-tabs>li.active>a:hover{
    background-color: #0080ff !important;
    border: medium none;
    border-radius: 0;
    color:#fff;
}