.lesson-content{max-width:none}.lesson-header{margin-bottom:2rem;padding-bottom:1rem;border-bottom:2px solid #e9ecef}.lesson-header h1{margin:0 0 1rem 0;color:#2c3e50}.breadcrumb{font-size:0.9rem;color:#6c757d}.breadcrumb a{color:#007bff;text-decoration:none}.breadcrumb a:hover{text-decoration:underline}.lesson-body{line-height:1.6}.lesson-body h2{margin-top:2rem;color:#495057}.lesson-body pre{background:#f8f9fa;padding:1rem;border-radius:4px;overflow-x:auto}.lesson-navigation{margin-top:3rem;padding-top:2rem;border-top:1px solid #e9ecef}.nav-links{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:1rem}.btn{display:inline-block;padding:0.5rem 1rem;border-radius:4px;text-decoration:none;font-weight:500;transition:all 0.3s ease}.btn-outline{border:2px solid #6c757d;color:#6c757d}.btn-outline:hover{background:#6c757d;color:white}.btn-primary{background:#007bff;color:white;border:2px solid #007bff}.btn-primary:hover{background:#0056b3;border-color:#0056b3}@media (max-width: 992px){.content-wrapper{flex-direction:column}}@media (max-width: 768px){.nav-links{flex-direction:column;align-items:stretch}.btn{text-align:center}}