.theme-popup { position: relative left: 10px z-index: 1000; border-radius: 4px font-size: 0.7em .theme { margin: 0 padding: 2px 10px line-height: 25px white-space: nowrap } } @media only screen and (max-width: 1250px) { .nav-chapters { display: none } .mobile-nav-chapters { font-size: 2.5em text-align: center text-decoration: none max-width: 150px min-width: 90px justify-content: center align-content: center position: relative display: inline-block margin-bottom: 50px border-radius: 5px } .next { float: right } .previous { float: left } }