.nav-chapters {
    font-size: 2.5em
    text-align: center
    text-decoration: none

    position: absolute
    top: 50px /* Height of menu-bar */
    bottom: 0
    margin: 0
    max-width: 150px
    min-width: 90px
    display: flex
    justify-content: center
    align-content: center
    flex-direction: column

    transition: color 0.5s
}

.mobile-nav-chapters { display: none }
.nav-chapters:hover { text-decoration: none }
.previous { left: 0 }
.next { right: 15px }