/* Books refinement: quiet navigation and a balanced reading canvas. */
/* Hide scrollbar chrome without changing scrolling, touch, or keyboard behavior. */
html,body,.bk-sidebar,.bk-filters,.er-toc-list,.er-modes,.er-reader table,.er-reader pre{
  scrollbar-width:none;
  -ms-overflow-style:none;
}
html::-webkit-scrollbar,body::-webkit-scrollbar,
.bk-sidebar::-webkit-scrollbar,.bk-filters::-webkit-scrollbar,
.er-toc-list::-webkit-scrollbar,.er-modes::-webkit-scrollbar,
.er-reader table::-webkit-scrollbar,.er-reader pre::-webkit-scrollbar{
  display:none;width:0;height:0;
}
html{scrollbar-gutter:auto}
.bk-sidebar{padding-top:22px;overflow-x:hidden;overflow-y:auto}
.bk-primary-nav>a{padding-inline:11px}
.bk-primary-nav>a>small{flex-shrink:0}
.bk-sidebar-heading{padding-top:26px}
.bk-side-bottom{padding-top:20px}
/* Contents keeps the chapter list prominent. Section links are a disclosure. */
.er-toc{padding:10px}
.er-toc-header{padding:18px 12px 20px;gap:8px}
.er-toc-header strong{font-size:14px;line-height:1.4}
.er-toc-header span{font-size:11px}
.er-toc-list{overscroll-behavior:contain;padding-bottom:24px;scroll-padding-block:12px}
.er-toc-item>a{padding:11px 10px;gap:8px;border-radius:7px;align-items:baseline;line-height:1.5}
.er-toc-num{min-width:19px;font-size:10px;opacity:.8}
.er-toc-outline{margin:5px 0 12px 36px;color:var(--er-ink-muted)}
.er-toc-outline summary{cursor:pointer;font-size:10px;line-height:1.6;padding:7px 0;list-style:none;display:flex;align-items:center;gap:7px}
.er-toc-outline summary::-webkit-details-marker{display:none}
.er-toc-outline summary:before{content:'›';font-size:14px;line-height:1;transition:transform .15s}
.er-toc-outline[open] summary:before{transform:rotate(90deg)}
.er-toc-outline summary:hover{color:var(--er-accent)}
.er-toc-outline summary:focus-visible{outline:2px solid var(--er-accent);outline-offset:3px;border-radius:3px}
.er-toc-outline .er-toc-sections{margin:3px 0 0 3px;padding:0 0 2px 12px;border-left:1px solid var(--er-border)}
.er-toc-outline .er-toc-sections a{padding:6px 0;font-size:10px;line-height:1.5}
/* Align heading, text columns, and chapter navigation on the same measure. */
.er-reader{padding:48px clamp(28px,4.5vw,72px) 64px}
.er-prose{width:100%}
.er-chapter-header{margin-bottom:34px;padding-bottom:27px}
.er-title{font-size:34px;line-height:1.3}
.er-han-title{font-size:9px;letter-spacing:1.8px;margin-bottom:13px}
.er-meta{font-size:12px}
.er-shell[data-mode=parallel] .er-prose{max-width:70rem}
.er-shell[data-mode=parallel] :is(.er-chapter-header,.er-reading-status,.er-nav){max-width:70rem}
.er-shell[data-mode=parallel] .er-layers{gap:0 40px;align-items:start}
.er-layer-title,.er-layer[data-layer=original] .er-layer-title{
  font-family:var(--er-font-sans);font-size:10px;font-weight:550;letter-spacing:1px;
  line-height:1.6;margin:0 0 23px;color:var(--er-ink-muted);
}
.er-shell[data-mode=parallel] .er-layer[data-layer=original]{
  font-size:calc(var(--er-size,19px)*1.18);line-height:1.95;letter-spacing:.055em;
}
.er-layer[data-layer=literary]{line-height:var(--er-leading,1.85)}
.er-layer h2:not(.er-layer-title){font-family:var(--er-font-sans);font-size:11px;font-weight:550;letter-spacing:.2px;margin:28px 0 17px;line-height:1.6}
.er-layer[data-layer=literary]>.er-layer-title+h2{margin-top:0}
.er-layer p{margin-bottom:1.15em}
.er-reading-status{margin-top:28px}
.er-nav{padding-top:21px}
@media(min-width:901px){
  .er-shell[data-mode=parallel] .er-layers{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .er-shell[data-mode=parallel] .er-layer[data-layer=literary]{border-left:1px solid var(--er-border);padding-left:32px}
  .er-topbar{padding-inline:22px;gap:15px}
  .er-modes button{padding-inline:12px}
}
@media(min-width:1600px){.er-reader{padding-inline:80px}.er-shell[data-mode=parallel] .er-layers{column-gap:48px}.er-shell[data-mode=parallel] .er-layer[data-layer=literary]{padding-left:40px}}
@media(max-width:1100px) and (min-width:901px){.er-topbar{gap:9px;padding-inline:14px}.er-modes button{padding-inline:8px}.er-reader{padding-inline:30px}.er-shell[data-mode=parallel] .er-layers{column-gap:25px}.er-shell[data-mode=parallel] .er-layer[data-layer=literary]{padding-left:22px}}
@media(max-width:900px){
  .er-reader{padding:36px 25px 45px}
  .er-title{font-size:31px}
  .er-chapter-header{margin-bottom:29px;padding-bottom:23px}
  .er-shell[data-mode=parallel] .er-layers{grid-template-columns:1fr;row-gap:14px}
  .er-shell[data-mode=parallel] .er-layer[data-layer=literary]{border-top:1px solid var(--er-border);padding-top:27px}
  .er-toc-outline summary{font-size:11px;min-height:36px}
}
@media(max-width:600px){.er-reader{padding:32px 22px 40px}.er-title{font-size:29px}.er-toc-item>a{font-size:13px;padding:12px 10px}.er-meta{font-size:11px}.er-layer-title{margin-bottom:19px}}
@media(prefers-reduced-motion:reduce){.er-toc-outline summary:before{transition:none}}