/* Four consistent chapters shared by every active case page. */
.study-page .case-chapter { padding-block:64px; scroll-margin-top:calc(var(--case-header-height) + var(--case-navigation-height,58px) + 24px); }
.study-page .case-chapter-label { display:flex; align-items:center; gap:10px; margin:0 0 20px; max-width:none; font-size:13px; line-height:1.5; font-weight:600; color:var(--text-secondary); }
.case-chapter-label>span:first-child { display:grid; place-items:center; flex:0 0 30px; min-height:24px; border-radius:6px; background:var(--surface); color:var(--text-main); font-variant-numeric:tabular-nums; }
.case-nav-number { margin-right:8px; font-size:12px; font-variant-numeric:tabular-nums; }
.case-chapter .case-section-intro { max-width:900px; }
.chapter-rationale { margin:24px 0 32px; }
.chapter-rationale-content { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:24px; margin:0 24px; padding:24px 0; border-top:1px solid var(--panel-line); }
.chapter-rationale-content dt { margin:0 0 10px; font-size:15px; line-height:1.5; font-weight:650; }
.chapter-rationale-content dd { margin:0; color:var(--text-secondary); font-size:14px; line-height:1.7; }
.chapter-rules { display:grid; grid-template-columns:1fr 1fr; border:1px solid var(--panel-line); border-radius:16px; overflow:hidden; }
.chapter-rule-panel { min-width:0; padding:28px; background:var(--surface); }
.chapter-rule-panel+.chapter-rule-panel { border-left:1px solid var(--panel-line); background:var(--surface-raised); }
.study-page .chapter-rule-panel>h3 { margin:0 0 18px; font-size:19px; line-height:1.4; }
.chapter-rule-panel ul { list-style:none; margin:0; padding:0; }
.chapter-rule-panel li { display:flex; align-items:flex-start; gap:12px; padding:14px 0; border-top:1px solid var(--panel-line); color:var(--text-secondary); font-size:14px; line-height:1.7; }
.chapter-rule-panel li:first-child { padding-top:0; border-top:0; }
.chapter-rule-panel li:last-child { padding-bottom:0; }
.chapter-rule-panel .study-icon { width:18px; height:18px; flex:0 0 18px; margin-top:3px; color:#27834d; }
.chapter-rule-panel+.chapter-rule-panel .study-icon { color:#356b9b; }
.study-page .chapter-results-heading { margin:32px 0 6px; font-size:20px; }
.study-page .chapter-results-period { margin:0 0 20px; color:var(--text-secondary); font-size:14px; line-height:1.5; }
.study-page :is(.study-hero-stats,.study-result-metrics)>div { display:grid; grid-template-rows:max-content 1fr; align-content:start; align-items:start; min-width:0; }
.study-page :is(.study-hero-stats,.study-result-metrics) dd { grid-row:1; }
.study-page :is(.study-hero-stats,.study-result-metrics) dt { grid-row:2; }
.chapter-method-grid { display:grid; grid-template-columns:1fr 1fr; gap:20px; }
.chapter-panel { min-width:0; padding:28px; border:1px solid var(--panel-line); border-radius:16px; background:var(--surface-raised); }
.chapter-panel:first-child { background:var(--surface); }
.study-page .chapter-panel>h3 { margin:0 0 22px; font-size:21px; }
/* Original brand artwork sits directly on the page, without white tiles. */
.study-page .study-brand img { background:transparent; border:0; border-radius:0; }
.study-page .study-brand.brand-wordmark img { padding:0; width:78px; }
.chapter-service-list { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:16px 20px; margin-bottom:24px; }
.chapter-service-list .study-brand { min-height:28px; font-size:13px; font-weight:550; }
.chapter-service-list .study-brand img { width:28px; height:28px; }
.chapter-service-list .study-brand.brand-wordmark img { width:84px; }
.chapter-facts { display:block; margin:0; padding:0; }
.chapter-facts>div { display:grid; grid-template-columns:minmax(0,0.8fr) minmax(0,1.2fr); align-items:baseline; gap:16px; min-width:0; padding:15px 0; border-top:1px solid var(--panel-line); }
.chapter-facts>div:last-child { padding-bottom:0; }
.chapter-facts dt { margin:0; color:var(--text-secondary); font-size:13px; line-height:1.6; }
.chapter-facts dd { margin:0; color:var(--text-main); font-size:14px; font-weight:550; line-height:1.6; overflow-wrap:break-word; }
.study-page .chapter-method-note { margin:24px 0 0; padding-top:20px; border-top:1px solid var(--panel-line); font-size:13px; line-height:1.7; }
.chapter-detail-content { margin:0 24px; padding:24px 0; border-top:1px solid var(--panel-line); }
.chapter-detail-content h4 { margin:0 0 16px; font-size:16px; font-weight:650; line-height:1.5; }
.study-page .chapter-detail-content>p { font-size:14px; line-height:1.7; }
.chapter-process-list { margin:0 0 24px; padding-left:20px; }
.chapter-process-list li { padding:12px 0; }
.chapter-process-list li:first-child { padding-top:0; }
.chapter-process-list li::marker { color:var(--text-secondary); font-size:13px; font-variant-numeric:tabular-nums; }
.chapter-process-list strong { font-size:15px; line-height:1.6; font-weight:650; }
.study-page .chapter-process-list p { margin-top:4px; font-size:14px; line-height:1.7; }
.metric-definition-list { margin-bottom:0; }
.metric-definition-list>div { padding:20px 0; border-bottom:1px solid var(--panel-line); }
.metric-definition-list>div:first-child { padding-top:0; }
.metric-definition-list>div:last-child { padding-bottom:0; border-bottom:0; }
.metric-definition-list dt { margin-bottom:8px; font-size:15px; line-height:1.6; font-weight:650; }
.metric-definition-list dd { margin:0; max-width:76ch; color:var(--text-secondary); font-size:14px; line-height:1.7; }
@media(max-width:900px) {
  .chapter-rationale-content { grid-template-columns:1fr; }
  .chapter-rules,.chapter-method-grid { grid-template-columns:1fr; }
  .chapter-rule-panel+.chapter-rule-panel { border-left:0; border-top:1px solid var(--panel-line); }
}
@media(max-width:650px) {
  .study-page .case-chapter { padding-block:40px; }
  .study-page .case-chapter-label { margin-bottom:16px; font-size:12px; }
  .case-navigation nav { gap:20px; }
  .case-navigation a { font-size:13px; }
  .case-nav-number { margin-right:6px; font-size:11px; }
  .chapter-rule-panel,.chapter-panel { padding:20px; }
  .study-page .chapter-rule-panel>h3 { font-size:18px; }
  .chapter-rule-panel li { gap:10px; }
  .study-page .chapter-panel>h3 { font-size:20px; margin-bottom:18px; }
  .chapter-facts>div { grid-template-columns:1fr; gap:4px; padding-block:14px; }
  .chapter-facts dd { font-size:14px; }
  .chapter-detail-content { margin-inline:20px; padding-block:20px; }
}