.chapter-navigation{position:sticky;z-index:20;border-block:1px solid var(--chapter-line);font-size:.875rem;background:var(--chapter-ground);color:var(--chapter-ink)}.chapter-navigation[hidden]{display:none}.chapter-navigation-inner{max-width:76rem;margin:auto;padding-inline:clamp(12px,2vw,32px);display:flex;align-items:center;gap:12px}.chapter-rail{flex:1;min-width:0;display:flex;gap:4px;list-style:none;margin:0;padding:4px 0;overflow-x:auto;overscroll-behavior-x:contain;scrollbar-width:none}.chapter-rail::-webkit-scrollbar{display:none}.chapter-rail li{flex:none}.chapter-rail a{display:flex;align-items:center;min-height:44px;padding:10px 12px;border-bottom:2px solid transparent;white-space:nowrap;color:inherit;text-decoration:none;font-weight:600}.chapter-rail a[aria-current]{border-color:var(--chapter-accent);background:color-mix(in srgb,var(--chapter-accent) 7%,transparent)}.chapter-navigation a:hover{background:color-mix(in srgb,var(--chapter-accent) 7%,transparent)}.chapter-menu{position:relative;flex:none}.chapter-menu summary{cursor:pointer;min-height:44px;display:flex;align-items:center;gap:8px;font-weight:600;list-style:none;padding:8px;border-radius:6px}.chapter-menu summary::-webkit-details-marker{display:none}.chapter-caret{flex:none;transition:transform .15s}.chapter-menu[open] .chapter-caret{transform:rotate(180deg)}.chapter-menu ol{position:absolute;top:calc(100% + 6px);inset-inline-end:0;width:min(27rem,calc(100vw - 24px));max-height:var(--chapter-menu-space,50dvh);overflow:auto;overscroll-behavior:contain;list-style:none;margin:0;padding:6px;background:var(--chapter-panel);border:1px solid var(--chapter-line);border-radius:10px;box-shadow:0 12px 32px #10243918}.chapter-menu a{display:flex;align-items:center;min-height:48px;padding:12px;border-radius:6px;line-height:1.4;overflow-wrap:anywhere;text-decoration:none;color:inherit}.chapter-menu a[aria-current]{font-weight:650;background:color-mix(in srgb,var(--chapter-accent) 9%,transparent)}.chapter-picker-label,.chapter-picker-current{display:none}.chapter-navigation :is(summary,a):focus-visible{outline:2px solid var(--chapter-focus);outline-offset:-2px}@media(min-width:768px){.chapter-menu[data-overflow=false]{display:none}}@media(max-width:767px){.chapter-navigation-inner{padding-inline:12px}.chapter-rail,.chapter-desktop-label{display:none}.chapter-menu{width:100%}.chapter-menu summary{min-height:50px;padding:8px 4px;gap:8px}.chapter-picker-label{display:block;flex:none;font-weight:400;font-size:12px;color:var(--chapter-soft)}.chapter-picker-current{display:block;min-width:0;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px}.chapter-picker-current:before{content:"·";margin-inline-end:8px;color:var(--chapter-soft)}.chapter-menu ol{width:100%;inset-inline:0}.chapter-menu a{font-size:16px}}@media(prefers-reduced-motion:reduce){.chapter-caret{transition:none}}@media print{.chapter-navigation{display:none}}