.section {
    display: none;
}

.section.active{
    display: block;
}

.nav .intro-x {
    cursor: pointer;
    opacity: .5;
}

.nav .intro-x .active {
    cursor: pointer;
    opacity: .5;
}

.next,
.previous {
    outline: none;
    cursor: pointer;
}

.next.disable,
.previous.disable{
    cursor: none;
    opacity: .5;
}