mark{
    background: #2d8ceb;
    color: white;
}

mark.active{
    border-bottom: 1px solid white;
}

.nav li a {
    color: rgba(255,255,255,0.3);
    padding-bottom: 3px;
    padding-top: 2px;
}
.nav .active a {
    color: rgba(255,255,255,0.6);
}

.nav .active {
    border-left: 2px solid rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.5);
}

.nav .nav {
    margin-left:4px;
  display: none;
}

.nav .active .nav {
  display: block;
}

.nav .nav a {
  font-weight: normal;
}

.nav .nav span {
  
}

.nav .nav .active a,
.nav .nav .active:hover a,
.nav .nav .active:focus a {
  
}

.nav .nav .active span,
.nav .nav .active:hover span,
.nav .nav .active:focus span {
  display: none;
}

.chapter {
    margin-bottom: 50px;
}

.subchapter1 {
    margin-top: 35px;
    margin-bottom: 35px;
}

.openinbrowserbutton {
    backface-visibility: hidden;
    color: rgba(255,255,255,0.8);
}
.openinbrowserbutton {
    color: rgba(255,255,255,1);
}
