.formula-panel .formula-layout{display:grid;grid-template-columns:minmax(190px,250px) minmax(0,1fr);gap:22px;align-items:start;margin:22px 0}
.formula-lesson-list{display:grid;gap:8px;max-height:70vh;overflow:auto;position:sticky;top:14px}
.formula-lesson-link{width:100%;text-align:left;padding:12px 14px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--navy);font:inherit;line-height:1.4}
.formula-lesson-link:hover,.formula-lesson-link:focus-visible{border-color:var(--gold);outline:2px solid #c9a22760;outline-offset:2px}
.formula-lesson-link.selected{background:var(--navy);border-color:var(--navy);color:#fff;font-weight:650}
.formula-lesson{min-width:0;border:1px solid var(--line);border-top:5px solid var(--gold);border-radius:10px;padding:24px;line-height:1.7;background:#fff}
.formula-lesson h3{font:600 25px Fraunces,Georgia,serif;color:var(--navy);margin:0 0 18px}
.formula-lesson h4{font-size:17px;line-height:1.35;color:var(--navy);margin:0 0 12px}
.formula-key-point{padding:18px 20px;border:1px solid #b5d5df;border-left:6px solid #087c91;border-radius:8px;background:#edf6f8;margin:0 0 24px}
.formula-key-point p{margin:6px 0 0;font-size:18px;line-height:1.6;font-weight:650;color:#14243e}
.formula-section-label{display:inline-block;text-transform:uppercase;letter-spacing:.07em;font-size:13px;font-weight:750;color:#075e70}
.formula-content-section,.formula-visual-section,.formula-example,.formula-notes{margin:24px 0 0}
.formula-list{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.formula-list li{padding:14px 16px;margin:0;border:1px solid #d8e1eb;border-left:4px solid #526277;border-radius:7px;background:#f7f9fc;line-height:1.65;font-size:16px}
.formula-example,.formula-notes{padding:17px 19px;border-radius:8px}
.formula-example{background:#f2f6fb;border-left:5px solid #245b8f}
.formula-notes{background:#fff8e7;border-left:5px solid #b28a08}
.formula-example p,.formula-notes p{margin:0;font-size:16px;line-height:1.7}
.formula-example p+p{margin-top:10px}.formula-note-list{padding-left:22px;margin:0}.formula-note-list li{padding-left:4px;margin:0 0 10px;font-size:16px;line-height:1.65}.formula-note-list li:last-child{margin-bottom:0}
.formula-diagram-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.formula-diagram{min-width:0;margin:0;border:1px solid #d8e1eb;border-radius:8px;background:#fbfcfd;padding:12px;overflow:hidden}
.formula-diagram svg{display:block;width:100%;height:auto;margin:auto}
.formula-diagram text{font:14px Arial,sans-serif;fill:#334155}
.formula-diagram figcaption{padding:9px 3px 1px;color:#334155;font-size:14px;line-height:1.5}
.formula-course-notes{padding:14px 16px;border-left:4px solid var(--gold);background:#fff9e7;margin:16px 0;line-height:1.7}
.formula-course-notes summary{cursor:pointer;font-weight:650;color:var(--navy)}
.formula-course-notes li{margin:0 0 10px;line-height:1.65}
.formula-provenance{margin-top:22px;border-top:1px solid var(--line);padding-top:12px}
.formula-panel .review-menu{display:flex;gap:8px;flex-wrap:wrap}
@media(max-width:760px){.formula-panel .formula-layout{grid-template-columns:1fr}.formula-lesson-list{position:static;max-height:240px;grid-template-columns:repeat(2,minmax(0,1fr))}.formula-lesson{padding:19px}}
@media(max-width:560px){.formula-lesson-list{grid-template-columns:1fr}.formula-lesson{padding:16px}.formula-diagram-grid{grid-template-columns:1fr}.formula-key-point p{font-size:17px}}
.formula-panel{padding:22px;background:#fff;border:1px solid var(--line);border-radius:12px}.formula-panel .dash-heading{display:flex;align-items:center;gap:14px;flex-wrap:wrap}.formula-panel .dash-note{color:#526277;line-height:1.6}.formula-panel .btn-ghost{padding:10px 14px;background:#fff;border:1px solid var(--line);border-radius:8px;color:var(--navy);font:inherit;cursor:pointer}.formula-panel .revision-badge{padding:6px 10px;background:#edf2f7;border-radius:6px}