.teach-section{background:#efe9dc}.teach-intro{max-width:720px;color:var(--muted);font-size:18px;margin:-10px 0 34px}.classroom{display:grid;grid-template-columns:260px minmax(0,1fr);gap:18px;align-items:start}.lesson-nav{display:grid;gap:8px;position:sticky;top:18px}.lesson-nav button{display:grid;grid-template-columns:32px 1fr;gap:10px;align-items:center;text-align:left;border:1px solid var(--line);background:rgba(255,253,248,.72);color:var(--ink);border-radius:13px;padding:11px 12px;font-weight:600}.lesson-nav button span:first-child{font-size:19px}.lesson-nav button small{display:block;color:var(--muted);font-weight:500;font-size:11px}.lesson-nav button.active{background:var(--ink);color:white;border-color:var(--ink)}.lesson-nav button.active small{color:#bed0cb}.teaching-stage{background:var(--card);border:1px solid var(--line);border-radius:24px;padding:clamp(24px,5vw,52px);min-height:650px;box-shadow:var(--shadow)}.lesson-number{font-size:12px;font-weight:700;color:var(--green);letter-spacing:.12em;text-transform:uppercase}.teaching-stage h3{font-family:Fraunces;font-size:clamp(34px,5vw,54px);line-height:1.04;margin:10px 0 18px}.lesson-goal{font-size:18px;color:var(--muted);max-width:680px}.teach-block{margin-top:34px}.teach-block h4{font-size:13px;text-transform:uppercase;letter-spacing:.1em;color:var(--green);margin-bottom:10px}.teach-block p{font-size:17px}.concept-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.concept-box{border:1px solid var(--line);border-radius:15px;padding:17px;background:white}.concept-box strong{display:block;margin-bottom:4px}.concept-box span{font-size:14px;color:var(--muted)}.example-pair{display:grid;grid-template-columns:1fr 1fr;gap:12px}.example-pair div{border-radius:15px;padding:18px}.yes-example{background:#e4f2df}.no-example{background:#f8e1d8}.example-pair b{display:block;margin-bottom:6px}.exam-trap{background:var(--navy);color:white;border-radius:16px;padding:20px}.exam-trap strong{color:var(--lime)}.check-box{border:2px solid var(--ink);border-radius:17px;padding:20px}.check-box p{font-weight:600}.check-options{display:flex;gap:8px;flex-wrap:wrap}.check-options button{border:1px solid var(--line);background:white;border-radius:10px;padding:9px 13px}.check-options button.good{background:#dff2d8;border-color:#69a86b}.check-options button.bad{background:#f7d9d0;border-color:#c76d54}.check-feedback{font-size:14px;margin-top:11px;color:var(--muted)}.lesson-finish{margin-top:30px;display:flex;justify-content:space-between;align-items:center;gap:12px}.lesson-finish button{border:0;border-radius:12px;padding:12px 16px;font-weight:700}.complete-lesson{background:var(--green);color:white}.next-lesson{background:white;border:1px solid var(--line)!important}@media(max-width:800px){.classroom{grid-template-columns:1fr}.lesson-nav{position:static;display:flex;overflow-x:auto;padding-bottom:7px;scroll-snap-type:x mandatory}.lesson-nav button{min-width:190px;scroll-snap-align:start}.teaching-stage{min-height:0}.concept-grid,.example-pair{grid-template-columns:1fr}}@media(max-width:480px){.lesson-finish{align-items:stretch;flex-direction:column}.lesson-finish button{width:100%}}