.lesson{background:var(--background);padding:4rem 0 6rem}.lesson-header{text-align:center;max-width:800px;margin:0 auto 4rem}.lesson-badge{background:var(--primary-light);color:var(--primary);border-radius:999px;margin-bottom:1rem;padding:.45rem .9rem;font-size:.85rem;font-weight:600;display:inline-block}.lesson-header h1{color:var(--text);margin-bottom:1rem;font-size:3rem}.lesson-description{color:var(--text-secondary);font-size:1.15rem;line-height:1.8}.lesson-meta{justify-content:center;gap:1rem;margin-top:2rem;display:flex}.difficulty,.reading-time{background:var(--surface);border:1px solid var(--border);border-radius:999px;padding:.55rem 1rem;font-weight:600}.lesson-content{max-width:900px;margin:auto}.lesson-content h2{color:var(--text);margin-top:3rem;margin-bottom:1rem;font-size:2rem}.lesson-content h3{color:var(--text);margin-top:2rem;margin-bottom:.75rem}.lesson-content p{color:var(--text-secondary);margin-bottom:1.4rem;line-height:1.9}.lesson-content ul{margin-bottom:2rem;padding-left:1.5rem}.lesson-content li{color:var(--text-secondary);margin-bottom:.8rem}.lesson-content strong{color:var(--text)}.next-lesson{max-width:900px;margin:5rem auto 0}.next-card{border-radius:var(--radius-lg);background:var(--surface);border:1px solid var(--border);justify-content:space-between;align-items:center;gap:2rem;padding:2rem;text-decoration:none;transition:all .25s;display:flex}.next-card:hover{box-shadow:var(--shadow-md);border-color:var(--primary);transform:translateY(-4px)}.next-label{color:var(--primary);text-transform:uppercase;letter-spacing:.05em;font-size:.85rem;font-weight:700}.next-card h3{color:var(--text);margin:.5rem 0}.next-card p{color:var(--text-secondary);margin:0}.next-arrow{color:var(--primary);font-size:2rem;font-weight:700}.lesson-illustration{width:100%;max-width:700px;margin:0 auto 4rem;display:block}.lesson-checklist{grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1rem;margin-top:2rem;display:grid}.lesson-checklist div{background:var(--surface);border-radius:var(--radius-md);border:1px solid var(--border);padding:1.2rem;font-weight:500}.lesson-warning{border-left:5px solid var(--bearish);border-radius:var(--radius-md);background:#fef2f2;margin-top:1.5rem;padding:1.5rem}.lesson-warning ul{margin:0;padding-left:1.2rem}.lesson-image{border:1px solid #ddd;border-radius:12px;width:100%;max-width:500px;margin:2rem auto;display:block;box-shadow:0 10px 30px #00000026}.lesson-conversion{text-align:center;color:#fff;background:linear-gradient(135deg,#2563eb,#1d4ed8);border-radius:24px;margin-top:5rem;padding:4rem 2rem;box-shadow:0 25px 60px #2563eb59}.conversion-icon{margin-bottom:1rem;font-size:4rem}.conversion-tag{letter-spacing:.08em;background:#fff3;border-radius:999px;margin-bottom:1.5rem;padding:.5rem 1rem;font-size:.85rem;font-weight:700;display:inline-block}.lesson-conversion h2{color:#fff;margin-bottom:1rem;font-size:2.3rem}.lesson-conversion p{color:#ffffffeb;max-width:650px;margin:1rem auto;line-height:1.8}.conversion-features{grid-template-columns:repeat(2,1fr);gap:1rem;max-width:650px;margin:2.5rem auto;display:grid}.conversion-features div{background:#ffffff1f;border:1px solid #ffffff26;border-radius:12px;padding:1rem;font-weight:600}.conversion-button{color:#2563eb;background:#fff;border-radius:14px;margin-top:1rem;padding:1.2rem 2.5rem;font-size:1.1rem;font-weight:700;text-decoration:none;transition:all .25s;display:inline-block}.conversion-button:hover{transform:translateY(-4px);box-shadow:0 15px 35px #0003}.conversion-note{opacity:.85;margin-top:1.5rem;font-size:.9rem}.lesson-navigation{border-top:1px solid var(--border);grid-template-columns:repeat(2,1fr);gap:1.5rem;margin-top:5rem;padding-top:2rem;display:grid}.lesson-nav{border:1px solid var(--border);background:var(--surface);border-radius:14px;padding:1.5rem;text-decoration:none;transition:all .25s;display:block}.lesson-nav:hover{border-color:var(--primary);box-shadow:var(--shadow-md);transform:translateY(-3px)}.nav-label{color:var(--primary);text-transform:uppercase;letter-spacing:.04em;margin-bottom:.5rem;font-size:.85rem;font-weight:700;display:block}.lesson-nav h3{color:var(--text);margin:0;font-size:1.2rem;font-weight:700}.next{text-align:right}@media (width<=768px){.lesson-navigation{grid-template-columns:1fr}.next{text-align:left}}.lesson-navigation-right{justify-content:flex-end;display:flex}@media (width<=768px){.lesson-navigation-right{justify-content:center}}