.chapter-rail{position:absolute;right:3.5vw;bottom:78px;z-index:9;display:flex;gap:7px;padding:8px;background:#eeeee7aa;backdrop-filter:blur(8px);transition:background .4s}.chapter-rail button{border:1px solid transparent;padding:0;width:42px;height:50px;background:#182b23;color:#fff;cursor:pointer;position:relative;opacity:.55;transition:opacity .3s,transform .3s}.chapter-rail img{width:100%;height:100%;object-fit:cover;display:block}.chapter-rail span{position:absolute;left:4px;bottom:3px;font:9px monospace;text-shadow:0 1px 4px #000}.chapter-rail [aria-current="true"]{opacity:1;border-color:#d9fa79;transform:translateY(-4px)}.chapter-rail button:hover{opacity:1}.chapter-rail.expanded{background:#172d2444}.chapter-rail.expanded button{width:50px;height:58px}html[data-motion="off"] .chapter-rail{display:none}
@media(max-width:750px){.chapter-rail{right:6vw;bottom:65px;padding:5px;gap:4px}.chapter-rail button,.chapter-rail.expanded button{width:30px;height:37px}.chapter-rail span{font-size:8px}}