.app-shell{min-height:100vh}.topbar{position:sticky;top:0;z-index:80;height:72px;background:rgba(255,253,250,.94);backdrop-filter:blur(16px);border-bottom:1px solid var(--border);display:flex;align-items:center;padding:0 18px;gap:16px}.brand{display:flex;align-items:center;gap:10px;min-width:220px}.brand-mark{width:38px;height:38px;border-radius:13px;background:var(--peach);display:grid;place-items:center;font-family:var(--font-serif);font-size:1.2rem;color:var(--brown)}.brand strong{display:block}.brand small{display:block;color:var(--muted)}.mode-tabs{margin:auto}.top-actions{display:flex;align-items:center;gap:8px}.lesson-layout{display:grid;grid-template-columns:280px minmax(0,1fr) 300px;gap:16px;padding:16px;max-width:1600px;margin:0 auto}.lesson-layout.plan-collapsed{grid-template-columns:76px minmax(0,1fr) 300px}.lesson-layout.context-collapsed{grid-template-columns:280px minmax(0,1fr) 76px}.lesson-layout.plan-collapsed.context-collapsed{grid-template-columns:76px minmax(0,1fr) 76px}.sidebar,.context{position:sticky;top:88px;height:calc(100vh - 104px);overflow:auto}.sidebar{padding:12px}.sidebar-head{display:flex;align-items:center;justify-content:space-between;padding:4px 4px 10px}.stage-group{margin-bottom:9px}.stage-head{display:flex;align-items:center;gap:8px;padding:9px 8px;font-size:.78rem;color:var(--slate);font-weight:700}.stage-dot{width:8px;height:8px;border-radius:50%;background:var(--mist);flex:none}.stage-dot.done{background:var(--green)}.item-link{display:flex;align-items:flex-start;gap:9px;width:100%;border:0;background:transparent;text-align:left;padding:9px;border-radius:12px;color:var(--slate);font-size:.84rem}.item-link:hover{background:var(--fog)}.item-link.active{background:var(--blue-soft);color:var(--ink)}.item-index{width:24px;height:24px;border-radius:8px;background:var(--mist);display:grid;place-items:center;font-size:.7rem;flex:none}.item-link.done .item-index{background:var(--green-soft);color:var(--green)}.collapsed-label{display:none}.plan-collapsed .stage-title,.plan-collapsed .item-title,.plan-collapsed .sidebar-head h3{display:none}.plan-collapsed .item-link{justify-content:center}.workspace{min-width:0}.lesson-hero{padding:20px 22px;margin-bottom:14px}.hero-top{display:flex;align-items:flex-start;gap:14px}.hero-meta{display:flex;gap:8px;flex-wrap:wrap}.hero-progress{margin-top:15px}.material-card{min-height:560px}.material-head{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;margin-bottom:18px}.material-body{display:grid;gap:16px}.material-body ul,.material-body ol{margin:0;padding-left:22px}.material-footer{display:flex;align-items:center;gap:10px;margin-top:24px;padding-top:18px;border-top:1px solid var(--border)}.context{padding:12px}.context-tabs{margin-bottom:12px}.vocab-list{display:grid;gap:8px}.vocab-row{display:grid;grid-template-columns:1fr auto;gap:8px;align-items:center;padding:10px;border-radius:12px;background:var(--fog)}.vocab-row strong{display:block}.grammar-grid{display:grid;gap:12px}.grammar-card{padding:14px;border:1px solid var(--border);border-radius:15px;background:#fff}.route-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.route-card{border:1px solid var(--border);border-radius:15px;padding:14px;background:var(--fog)}.profile-text{font-size:1.08rem;line-height:1.7;background:var(--fog);border-radius:16px;padding:18px}.exercise-shell{border-top:4px solid var(--peach-strong)}.exercise-meta{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:12px}.exercise-question{font-size:1.08rem;font-weight:650}.matching-row,.sorting-row{display:grid;grid-template-columns:minmax(0,1fr) minmax(160px,.65fr);gap:10px;align-items:center}.completion-banner{display:grid;grid-template-columns:repeat(5,1fr);gap:10px}.full-screen .topbar,.full-screen .sidebar,.full-screen .context,.full-screen .lesson-hero{display:none}.full-screen .lesson-layout{display:block;padding:0;max-width:none}.full-screen .material-card{border-radius:0;min-height:100vh;border:0}.mobile-tabs{display:none}