.affix {
    top: 20px;
    z-index: 9999 !important;
    max-width: 24%
}

.nav-pills > li > a {
    border-radius: 0;
    color: #000 !important;
    border-left: #FEFEFE 2px solid;
    transition-duration: 0.5s;
    -moz-transition-duration: 0.5s;
    -webkit-transition-duration: 0.5s;
}

.nav-pills > li > a:hover {
    color: #304ffe !important;
    background-color: #FEFEFE !important;
}

.nav-pills > li.active > a, .nav-pills > li.active > a:focus, .nav-pills > li.active > a:hover {
    color: #304ffe !important;
    border: none;
    border-left: #304ffe 2px solid;
    background-color: #FEFEFE !important;
}

@media only screen and (max-width: 768px) {
    #book-nav {
        display: none;
    }
}