.detail-header{position:sticky;left:0;right:0;top:0;z-index:1}.menu-toggle{display:flex;cursor:pointer;padding:8px;border-radius:6px;transition:background-color .2s ease;color:var(--text-muted);background-color:var(--hover-bg);border:none;font-weight:500;border-radius:var(--radius-md)}.menu-toggle:hover{background-color:#334155}.menu-toggle svg{width:24px;height:24px;stroke:#94a3b8}.main-container{display:flex;min-height:calc(100vh - 64px);justify-content:center}.sidebar{width:300px;background:#0f172a;border-right:1px solid #334155;padding:24px;position:fixed;left:-300px;top:0;bottom:0;overflow-y:auto;z-index:100;max-height:100vh;transition:left .3s ease}.sidebar.open{left:0}.sidebar-title{font-size:18px;font-weight:600;color:#f1f5f9;margin-bottom:24px}.lesson-list{list-style:none;padding:0}.lesson-item{margin-bottom:8px;background:var(--bg-secondary);padding:0;border-radius:var(--radius-xl);border:1px solid var(--border-color)}.lesson-link{display:flex;align-items:center;padding:12px 16px;border-radius:8px;text-decoration:none;color:#94a3b8;transition:all .2s ease;position:relative}.lesson-link:hover{background-color:#1e293b;color:#e2e8f0}.lesson-link.active{background-color:#1e40af;color:#dbeafe;border-left:3px solid #3b82f6}.lesson-link.completed{color:#10b981}.lesson-icon{width:20px;height:20px;margin-right:12px;flex-shrink:0}.lesson-icon.completed{color:#10b981}.lesson-icon.active{color:#dbeafe}.content-wrapper{display:flex;margin-left:0;transition:margin-left .3s ease}.main-content{padding:32px;max-width:800px;background:#1e293b}.content-header{margin-bottom:32px}.content-title{font-size:32px;font-weight:700;color:#f1f5f9;line-height:1.2;margin-bottom:16px}.content-text p{font-size:16px;line-height:1.7;margin-bottom:24px;color:#cbd5e1}.content-text strong{color:#f1f5f9;font-weight:600}.section-title{font-size:24px;font-weight:600;color:#f1f5f9;margin-top:32px;margin-bottom:16px}.info-box{background-color:#0f172a;border:1px solid #3b82f6;border-radius:8px;padding:20px;margin:24px 0}.info-box p{margin:0;color:#cbd5e1}.toc-sidebar{width:250px;background:#0f172a;border-left:1px solid #334155;padding:32px 24px;position:sticky;top:0;bottom:0;max-height:100vh;overflow-y:auto;z-index:100;display:none}.toc-title{font-size:14px;font-weight:600;color:#94a3b8;text-transform:uppercase;letter-spacing:.05em;margin-bottom:16px}.toc-list{list-style:none;padding:0}.toc-list-sub{list-style:none;padding:0 15px}.toc-item{margin-bottom:4px}.toc-link{display:block;padding:8px 0;font-size:14px;color:#94a3b8;text-decoration:none;transition:color .2s ease;border-left:2px solid transparent;padding-left:12px}.toc-link:hover,.toc-link.active{color:#3b82f6;border-left-color:#3b82f6}.overlay{position:fixed;top:0;left:0;right:0;bottom:0;background-color:rgba(0,0,0,.7);z-index:99;opacity:0;visibility:hidden;transition:all .3s ease}.overlay.active{opacity:1;visibility:visible}@media(min-width:768px){.nav-menu{display:flex}.detail-header{position:static}.menu-toggle{display:none}.sidebar{position:sticky;left:0;width:300px}.content-wrapper{margin-left:0}.main-content{padding:48px}}@media(min-width:1024px){.toc-sidebar{display:block}.main-content{padding:48px 48px 48px 64px}}@media(min-width:1200px){.sidebar{width:320px}.toc-sidebar{width:250px}}.lesson-link:focus,.toc-link:focus,.menu-toggle:focus{outline:2px solid #3b82f6;outline-offset:2px}@keyframes slideIn{from{transform:translateX(-100%)}to{transform:translateX(0)}}.sidebar.open{animation:slideIn .3s ease}.sidebar::-webkit-scrollbar{width:6px}.sidebar::-webkit-scrollbar-track{background:#1e293b}.sidebar::-webkit-scrollbar-thumb{background:#475569;border-radius:3px}.sidebar::-webkit-scrollbar-thumb:hover{background:#64748b}.toc-sidebar::-webkit-scrollbar{width:6px}.toc-sidebar::-webkit-scrollbar-track{background:#1e293b}.toc-sidebar::-webkit-scrollbar-thumb{background:#475569;border-radius:3px}.toc-sidebar::-webkit-scrollbar-thumb:hover{background:#64748b}.content-text ul{margin-left:24px;margin-bottom:24px}.content-text li{margin-bottom:8px;color:#cbd5e1}.content-text li strong{color:#f1f5f9}[data-theme=light] .menu-toggle{background-color:var(--bg-tertiary);color:var(--text-secondary)}[data-theme=light] .menu-toggle:hover{background-color:var(--hover-bg)}[data-theme=light] .menu-toggle svg{stroke:var(--text-secondary)}[data-theme=light] .sidebar{background:var(--bg-secondary);border-right:1px solid var(--border-color)}[data-theme=light] .sidebar-title{color:var(--text-primary)}[data-theme=light] .lesson-link{color:var(--text-secondary)}[data-theme=light] .lesson-link:hover{background-color:var(--hover-bg);color:var(--text-primary)}[data-theme=light] .lesson-link.active{background-color:var(--accent-primary);color:#fff;border-left:3px solid var(--accent-primary)}[data-theme=light] .lesson-link.completed{color:var(--accent-secondary)}[data-theme=light] .lesson-icon{color:var(--text-secondary)}[data-theme=light] .lesson-icon.completed{color:var(--accent-secondary)}[data-theme=light] .lesson-icon.active{color:#fff}[data-theme=light] .main-content{background:var(--bg-primary)}[data-theme=light] .content-title{color:var(--text-primary)}[data-theme=light] .content-text p{color:var(--text-secondary)}[data-theme=light] .content-text strong{color:var(--text-primary)}[data-theme=light] .section-title{color:var(--text-primary)}[data-theme=light] .info-box{background-color:var(--bg-secondary);border:1px solid var(--accent-primary)}[data-theme=light] .info-box p{color:var(--text-secondary)}[data-theme=light] .toc-sidebar{background:var(--bg-secondary);border-left:1px solid var(--border-color)}[data-theme=light] .toc-title{color:var(--text-secondary)}[data-theme=light] .toc-link{color:var(--text-secondary)}[data-theme=light] .toc-link:hover,[data-theme=light] .toc-link.active{color:var(--accent-primary);border-left-color:var(--accent-primary)}[data-theme=light] .overlay{background-color:rgba(0,0,0,.5)}[data-theme=light] .lesson-link:focus,[data-theme=light] .toc-link:focus,[data-theme=light] .menu-toggle:focus{outline:2px solid var(--accent-primary);outline-offset:2px}[data-theme=light] .sidebar::-webkit-scrollbar-track{background:var(--bg-tertiary)}[data-theme=light] .sidebar::-webkit-scrollbar-thumb{background:var(--text-muted)}[data-theme=light] .sidebar::-webkit-scrollbar-thumb:hover{background:var(--text-secondary)}[data-theme=light] .toc-sidebar::-webkit-scrollbar-track{background:var(--bg-tertiary)}[data-theme=light] .toc-sidebar::-webkit-scrollbar-thumb{background:var(--text-muted)}[data-theme=light] .toc-sidebar::-webkit-scrollbar-thumb:hover{background:var(--text-secondary)}[data-theme=light] .content-text li{color:var(--text-secondary)}[data-theme=light] .content-text li strong{color:var(--text-primary)}