.chapter-card.featured{margin-top:14px;border-left:2px solid var(--accent);background:linear-gradient(90deg,rgba(130,184,216,.08),var(--surface) 38%)}
.topic-jump{padding:24px!important;background:linear-gradient(90deg,rgba(130,184,216,.08),transparent);border-left:2px solid var(--accent)}
.topic-jump h2{margin-top:0}.topic-jump .ghost-button{display:inline-block;margin-top:8px}
.formula{max-width:850px;margin:15px 0;padding:15px 18px;border-left:2px solid var(--accent);background:var(--surface-2);font:20px/1.6 Georgia,"Times New Roman","Noto Serif SC",serif;letter-spacing:.02em}
.formula i{font-style:italic}.formula span{color:var(--muted);font-size:.78em}
.property-grid .en{color:var(--muted);font:12px ui-monospace,monospace}
.inline-formula{display:block;margin:12px 0;padding:10px 13px;background:var(--surface-2);font:19px/1.6 Georgia,"Times New Roman","Noto Serif SC",serif}.inline-formula i{font-style:italic}
.course-qa>p:not(.eyebrow){max-width:850px;color:var(--muted)}.qa-list{display:grid;gap:14px;margin-top:24px;max-width:940px}.qa-list article{border:1px solid var(--line);background:var(--surface)}.qa-list h3{display:flex;align-items:flex-start;gap:12px;margin:0;padding:17px 19px;border-bottom:1px solid var(--line);font:18px/1.55 Georgia,"Noto Serif SC",serif}.qa-list h3 span{flex:0 0 auto;color:var(--accent);font:11px/1.8 ui-monospace,monospace;letter-spacing:.08em}.qa-list article>div{display:grid;grid-template-columns:24px 1fr;gap:10px;padding:17px 19px}.qa-list article>div>b{color:var(--accent);font:13px/1.7 ui-monospace,monospace}.qa-list article>div p{margin:0;color:#cbd1cd}.qa-list i{font-family:Georgia,"Times New Roman",serif;font-style:italic}@media(max-width:620px){.qa-list h3,.qa-list article>div{padding:15px}.qa-list article>div{grid-template-columns:1fr}.qa-list article>div>b{margin-bottom:-6px}}