/* Keep the source book's typography and vertical reading layout. */
html.m-both .pair:has(>.en):has(>.ja)>.en:not(:empty),
html.m-both .pair:has(>.en):has(>.ja)>.ja:not(:empty){
  border-bottom:1px solid var(--rule);
  padding-bottom:calc(.65*var(--u));
}
.pair>.shared{margin:0;font-family:var(--en);font-size:1em;font-weight:500;line-height:1.62;color:var(--ink)}
.shared-row>.shared{display:block}
html.m-en .pair>.shared{font-size:1.04em}
.math-gloss{font-family:var(--jp);font-size:.82em;line-height:1.8;color:var(--sub);margin:.65em 0 0}
html.m-en .math-gloss,html.m-ja .math-gloss{display:none}
.vector{font-weight:700;font-style:italic}
.eq-number{font-family:var(--en);font-size:.8em;text-align:right;color:var(--sub);margin:0 0 var(--u)}
.footnote-ref{font-size:.72em;vertical-align:super;line-height:0;padding-left:2px}
.footnote-row{margin-top:var(--u);margin-bottom:.3em}
.footnote-row>.shared{font-size:.82em;color:var(--sub)}
img{height:auto}

/* Paragraph spacing is explicit; text nodes before an element also count. */
html .ja .pp.pp-gap{margin-top:var(--u)}
html .ja .pp.pp-start{margin-top:0}
/* Each circled subquestion keeps its text, with room around the marker and item. */
.pair .opt.subitem{display:block;padding-left:2em;text-indent:0;margin-top:1.1em}
.pair .opt.subitem.subitem-first{margin-top:0}
.subitem-label{display:inline-block;width:2em;margin-left:-2em;text-indent:0}
.subitem .pp{padding-left:0;text-indent:0}
.section-parent{margin:0 0 var(--u);font-size:14px;color:var(--sub)}
.pager a{flex:1;min-width:0;overflow-wrap:break-word}
.pager .nx{text-align:right}
.pager .pager-direction{display:block;margin-bottom:.35em}
.toc a[aria-current=page]{color:var(--red);text-decoration:underline;text-underline-offset:.16em}