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/* Small chapter 8 matrix controls; values remain keyboard accessible. */
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/* The result remains readable when its derivation is folded. */
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.pipeline-trace h4{font:600 14px var(--sans);margin:0 0 12px}.pipeline-trace ol{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
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#pipeline-stages .lab-stage{justify-content:flex-start}
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#pipeline-stages canvas{aspect-ratio:1.45}
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.pipeline-trace .math.display{margin:3px 0;padding:3px 0}
.rk4-calculation{border-top:1px solid var(--line);padding:17px 20px;background:var(--paper);font:13px/1.8 var(--sans);min-width:0}
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/* Formula references keep native links, keyboard access and shareable fragments. */
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.equation-ref:hover,.equation-ref:focus-visible{text-decoration-style:solid}
.equation-ref.eq-no{text-decoration:none}.equation-ref.eq-no:hover{text-decoration:underline}
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.equation-target:target{background-color:#edf4e9;box-shadow:inset 0 0 0 1px #a6bca3}
.equation-target.equation-highlight{background-color:#fff0c9;box-shadow:inset 0 0 0 2px #b4873e;transition:background-color .2s ease}
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@media(max-width:600px){.equation-target{scroll-margin-top:85px}}
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.equation-preview-body .katex-display{text-align:left;margin:.4em 0}
.equation-preview-jump{flex:none;align-self:flex-end;margin-top:9px;font:12px/1.7 var(--sans);text-decoration:none}
.equation-preview-jump:hover{text-decoration:underline}
@media(max-width:600px){#equation-preview{padding:13px 14px 10px}.equation-preview-body .math.display{font-size:15px}}
@media print{#equation-preview{display:none!important}}

/* A persistent chapter tree and an equivalent left drawer on small screens. */
.page-layout{grid-template-columns:250px minmax(0,860px);gap:40px;max-width:1290px}
.sidebar-inner{top:80px;max-height:calc(100dvh - 92px);overflow-y:auto;overscroll-behavior:contain;scrollbar-width:thin;padding:8px 6px 22px 0}
.sidebar-heading{display:flex;align-items:center;justify-content:space-between;padding:5px 9px 17px;font:600 13px var(--sans)}.sidebar-heading a{text-decoration:none;color:var(--ink)}
.series-chapter{display:flex;gap:10px;padding:9px 10px;font:13px/1.6 var(--sans);color:var(--muted);text-decoration:none;border-radius:4px}.series-chapter>span{flex:none;font-size:11px;padding-top:2px}.series-chapter:hover{background:var(--wash)}.series-chapter.current{color:var(--accent);background:#e6efe9;font-weight:600}
#toc{margin:5px 0 12px 13px;padding-left:6px;border-left:1px solid var(--line)}#toc a{font-size:12px;padding:6px 7px;gap:7px}
#toggle-navigation,#close-navigation{display:none}.mobile-toc{display:none!important}.navigation-backdrop[hidden]{display:none}.navigation-backdrop{position:fixed;inset:0;background:#172d365c;z-index:39}
@media(max-width:1100px){.page-layout{grid-template-columns:220px minmax(0,1fr);gap:24px}}
@media(max-width:850px){.page-layout{display:block}.sidebar{display:none;position:fixed;inset:0 auto 0 0;width:min(340px,86vw);z-index:40;background:var(--paper);box-shadow:8px 0 25px #18352930;padding:15px}.sidebar.is-open{display:block}.sidebar-inner{position:static;max-height:calc(100dvh - 30px);height:100%;padding:0 3px}.sidebar-heading{position:sticky;top:0;background:var(--paper);z-index:1;padding:10px 7px 16px}#toggle-navigation,#close-navigation{display:inline-block}.navigation-open{overflow:hidden}.series-chapter{padding:10px}#toc a{padding:8px}}
@media print{.sidebar,#toggle-navigation,.navigation-backdrop{display:none!important}}
/* Keep the geometry next to its controls instead of stretching the canvas with them. */
.concept-lab .lab-stage,#tree-rnea .lab-stage{justify-content:flex-start;align-self:start;position:sticky;top:82px}.concept-lab canvas,#tree-rnea canvas{aspect-ratio:1.25;width:100%}.concept-lab .lab-grid,#tree-rnea .lab-grid{align-items:start}.concept-lab .lab-controls,#tree-rnea .lab-controls{min-width:0}
@media(max-width:600px){.concept-lab .lab-stage,#tree-rnea .lab-stage{position:static}.concept-lab canvas,#tree-rnea canvas{aspect-ratio:1.15}}
.concept-steps{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:12px 18px;border-top:1px solid var(--line);width:100%;font:12px var(--sans)}.concept-steps button:disabled{opacity:.4;cursor:default}
.concept-trace,.rnea-work{padding:18px 20px;border-top:1px solid var(--line);background:var(--paper);width:100%;min-width:0}.concept-trace>strong,.rnea-work h4{font:600 14px/1.7 var(--sans);color:var(--accent);margin:0 0 8px}.concept-trace p,.rnea-work>p{font:13px/1.9 var(--sans);margin:8px 0 14px}.concept-trace .lab-readout,.rnea-work .lab-readout{max-width:100%;overflow:auto;font-size:14px}.rnea-terms{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:8px;margin:14px 0}.rnea-term{padding:10px;border:1px solid var(--line);border-radius:4px;background:var(--wash);min-width:0}.rnea-term[hidden]{display:none}.rnea-term>strong{font:12px/1.6 var(--sans);color:var(--muted)}.rnea-term .lab-readout{font-size:12px}.rnea-work .lab-calculation{margin-top:12px}#tree-rnea .lab-stage{position:static}#tree-rnea .lab-controls>.lab-calculation .control-row{padding:0 10px}#tree-rnea .lab-controls>.lab-calculation{margin:12px 0}
@media(max-width:600px){.rnea-work,.concept-trace{padding:14px}.rnea-terms{grid-template-columns:1fr}.rnea-term{display:grid;grid-template-columns:1fr 1fr;align-items:center}.rnea-term>strong{grid-column:1 / -1}.rnea-term .lab-readout{font-size:12px}}