.book-section-nav{top:var(--book-nav-top,81px);z-index:15;border-bottom:1px solid var(--line);background:color-mix(in srgb, var(--paper) 96%, transparent);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);position:sticky}.book-section-nav ul{scrollbar-width:none;gap:6px;margin-block:0;padding:7px 2px;list-style:none;display:flex;position:relative;overflow-x:auto}.book-section-nav ul::-webkit-scrollbar{display:none}.book-section-nav li{flex:none}.book-section-nav a{border:1px solid var(--line);background:var(--paper);min-height:36px;color:var(--ink);font-size:var(--fs-sm);white-space:nowrap;border-radius:999px;align-items:center;padding:0 14px;font-weight:700;text-decoration:none;display:inline-flex}.book-section-nav a:hover{border-color:var(--gold-600);background:var(--surface-hover);color:var(--text-strong)}.book-section-nav a:focus-visible{outline-offset:1px}.book-section-nav a[aria-current]{border-color:var(--gold-300);background:var(--gold-300);color:var(--text-on-gold)}@media (max-width:1080px),(pointer:coarse){.book-section-nav a{min-height:44px}}@media (max-height:520px){.book-section-nav{position:static}}.book-overview-page :is(.book-page-hero,.book-story-section,.book-inline-section,.book-figures){scroll-margin-top:calc(var(--book-nav-top,81px) + var(--book-nav-height,58px))}.book-overview-page #book-story-heading{scroll-margin-top:calc(var(--book-nav-top,81px) + var(--book-nav-height,58px) + 12px)}