.code-block-wrapper{margin:1.5rem 0;border-radius:8px;overflow:hidden;border:1px solid var(--color-border);background:#282c34}.code-header{display:flex;justify-content:space-between;align-items:center;padding:.5rem 1rem;background:#21252b;border-bottom:1px solid #181a1f}.code-language{font-family:var(--font-mono);font-size:.75rem;font-weight:500;color:#abb2bf;text-transform:uppercase;letter-spacing:.05em}.copy-button{padding:.25rem .75rem;background:transparent;border:1px solid #3e4451;border-radius:4px;font-family:var(--font-sans);font-size:.75rem;color:#abb2bf;cursor:pointer;transition:all var(--transition-fast)}.copy-button:hover{background:#3e4451;color:#e5e5e5}.copy-button:active{transform:scale(.98)}.code-content{margin:0!important;padding:1rem!important;font-size:.875rem!important;line-height:1.6!important;background:#282c34!important}.code-content code{font-family:var(--font-mono)!important}.code-content .linenumber{min-width:2.5em!important;padding-right:1em!important;color:#5c6370!important;text-align:right!important;-webkit-user-select:none;user-select:none}.code-content::-webkit-scrollbar{height:8px}.code-content::-webkit-scrollbar-track{background:#21252b}.code-content::-webkit-scrollbar-thumb{background:#3e4451;border-radius:4px}.code-content::-webkit-scrollbar-thumb:hover{background:#4b5263}@media(max-width:768px){.code-header{padding:.375rem .75rem}.code-content{padding:.75rem!important;font-size:.8125rem!important}}.mermaid-container{margin:1.5rem 0;padding:1.5rem;background:var(--color-bg-white);border:1px solid var(--color-border);border-radius:8px;overflow-x:auto;display:flex;justify-content:center}.mermaid-container svg{max-width:100%;height:auto}.mermaid-error{margin:1.5rem 0;padding:1rem 1.25rem;background:#fef2f2;border:1px solid #fecaca;border-left:4px solid #ef4444;border-radius:0 8px 8px 0;color:#991b1b}.mermaid-error .error-icon{margin-right:.5rem}.mermaid-error .mermaid-source{margin-top:1rem;padding:.75rem;background:#0000000d;border-radius:4px;font-family:var(--font-mono);font-size:.8125rem;overflow-x:auto;white-space:pre-wrap;color:#7f1d1d}@media(max-width:768px){.mermaid-container{padding:1rem}}.toc{max-height:calc(100vh - var(--header-height) - 4rem);overflow-y:auto;padding:1rem;background:var(--color-bg-white);border:1px solid var(--color-border);border-radius:8px;font-size:.875rem}.toc-title{font-weight:600;color:var(--color-text);margin-bottom:.75rem;padding-bottom:.5rem;border-bottom:1px solid var(--color-border)}.toc-list{list-style:none;padding:0;margin:0}.toc-item{margin:0}.toc-link{display:block;width:100%;padding:.375rem .5rem;background:none;border:none;border-left:2px solid transparent;text-align:left;color:var(--color-text-secondary);font-family:inherit;font-size:.8125rem;line-height:1.4;cursor:pointer;transition:all var(--transition-fast);border-radius:0 4px 4px 0}.toc-link:hover{color:var(--color-text);background:var(--color-bg-secondary)}.toc-link.active{color:var(--color-primary-light);border-left-color:var(--color-primary-light);background:#3b82f614}.toc-level-1 .toc-link{padding-left:.5rem;font-weight:500}.toc-level-2 .toc-link{padding-left:1rem}.toc-level-3 .toc-link{padding-left:1.5rem;font-size:.75rem}.toc-level-4 .toc-link{padding-left:2rem;font-size:.75rem}.toc::-webkit-scrollbar{width:4px}.toc::-webkit-scrollbar-thumb{background:var(--color-border);border-radius:2px}@media(max-width:1200px){.toc{display:none}}.chapter-wrapper{display:flex;gap:2rem;max-width:1200px;margin:0 auto}.chapter{flex:1;min-width:0;max-width:900px}.chapter-toc{flex-shrink:0;width:220px;align-self:flex-start;position:sticky;top:calc(var(--header-height) + 2rem)}@media(max-width:1200px){.chapter-wrapper{display:block}.chapter-toc{display:none}}.chapter-header{margin-bottom:2.5rem;padding-bottom:1.5rem;border-bottom:1px solid var(--color-border)}.chapter-header-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:.5rem}.chapter-position{font-size:.8125rem;font-weight:500;color:var(--color-primary-light)}.bookmark-btn{padding:.375rem .625rem;border:1px solid var(--color-border);border-radius:4px;background:var(--color-bg-white);color:var(--color-text-muted);font-size:1.25rem;cursor:pointer;transition:all var(--transition-fast);line-height:1}.bookmark-btn:hover{background:var(--color-bg-secondary);border-color:var(--color-text-muted)}.bookmark-btn.active{color:#f59e0b;border-color:#f59e0b}.chapter-title{font-size:2.25rem;font-weight:700;line-height:1.2;color:var(--color-text);margin-bottom:1rem}.chapter-tags{display:flex;flex-wrap:wrap;gap:.5rem}.chapter-content{font-size:1.0625rem;line-height:1.75}.chapter-content h1,.chapter-content h2,.chapter-content h3,.chapter-content h4{font-weight:600;line-height:1.3;color:var(--color-text);margin-top:2rem;margin-bottom:1rem}.chapter-content h1{font-size:1.875rem}.chapter-content h2{font-size:1.5rem}.chapter-content h3{font-size:1.25rem}.chapter-content h4{font-size:1.125rem}.chapter-content p{margin-bottom:1.25rem}.chapter-content ul,.chapter-content ol{margin-bottom:1.25rem;padding-left:1.5rem}.chapter-content li{margin-bottom:.5rem}.chapter-content li::marker{color:var(--color-primary-light)}.chapter-content .inline-code{padding:.125rem .375rem;font-size:.9em;background:var(--color-bg-secondary);border-radius:4px;color:var(--color-primary)}.table-wrapper{overflow-x:auto;margin:1.5rem 0}.chapter-content table{width:100%;border-collapse:collapse;font-size:.9375rem}.chapter-content th,.chapter-content td{padding:.75rem 1rem;border:1px solid var(--color-border);text-align:left}.chapter-content th{background:var(--color-bg-secondary);font-weight:600}.chapter-content tr:hover td{background:var(--color-bg)}.chapter-content .callout{margin:1.5rem 0;padding:1rem 1.25rem;background:linear-gradient(90deg,#3b82f614,#3b82f605);border-left:4px solid var(--color-primary-light);border-radius:0 8px 8px 0;color:var(--color-text)}.chapter-content .callout p{margin:0}.chapter-content a{color:var(--color-primary-light);text-decoration:underline;text-underline-offset:2px}.chapter-content a:hover{color:var(--color-primary)}.external-icon{font-size:.75em;margin-left:.25rem;opacity:.7}.chapter-content img{max-width:100%;height:auto;border-radius:8px;margin:1.5rem 0}.chapter-content hr{border:none;border-top:1px solid var(--color-border);margin:2rem 0}.chapter-nav{display:flex;align-items:center;justify-content:space-between;margin-top:3rem;padding-top:2rem;border-top:1px solid var(--color-border)}.nav-btn{display:flex;align-items:center;gap:.5rem;padding:.75rem 1.25rem;background:var(--color-bg-white);border:1px solid var(--color-border);border-radius:8px;font-size:.9375rem;font-weight:500;color:var(--color-text);transition:all var(--transition-fast)}.nav-btn:hover:not(:disabled){background:var(--color-bg-secondary);border-color:var(--color-border-dark)}.nav-btn-next:not(:disabled){background:var(--color-primary);border-color:var(--color-primary);color:#fff}.nav-btn-next:hover:not(:disabled){background:var(--color-primary-dark)}.nav-btn-arrow{font-size:1.125rem}.nav-shortcuts{display:flex;align-items:center;gap:.5rem;font-size:.8125rem;color:var(--color-text-muted)}@media(max-width:768px){.chapter-title{font-size:1.5rem}.chapter-content{font-size:1rem}.chapter-content h1{font-size:1.5rem}.chapter-content h2{font-size:1.25rem}.chapter-content h3{font-size:1.125rem}.chapter-content h4{font-size:1rem}.nav-shortcuts{display:none}.nav-btn{min-height:44px;min-width:44px;padding:.75rem 1rem;justify-content:center}.nav-btn-text{display:none}.nav-btn-arrow{font-size:1.5rem}.bookmark-btn{min-width:44px;min-height:44px;display:flex;align-items:center;justify-content:center}.chapter-header{margin-bottom:1.5rem;padding-bottom:1rem}.chapter-nav{margin-top:2rem;padding-top:1.5rem}.chapter-content th,.chapter-content td{padding:.5rem;font-size:.875rem}}@media(max-width:480px){.chapter-title{font-size:1.375rem}.chapter-position{font-size:.75rem}}.screen{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--color-bg) 0%,var(--color-bg-secondary) 100%)}.screen-content{text-align:center;padding:2rem}.loading-screen .loader{width:48px;height:48px;margin:0 auto 1.5rem;border:4px solid var(--color-border);border-top-color:var(--color-primary-light);border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.loading-screen p{font-size:1.125rem;color:var(--color-text-secondary)}.error-screen .error-icon{font-size:4rem;margin-bottom:1rem}.error-screen h1{font-size:1.5rem;font-weight:600;margin-bottom:.75rem;color:var(--color-text)}.error-screen p{font-size:1rem;color:var(--color-text-secondary);margin-bottom:1.5rem;max-width:400px}.retry-btn{padding:.75rem 1.5rem;background:var(--color-primary);border:none;border-radius:8px;font-size:.9375rem;font-weight:500;color:#fff;transition:background var(--transition-fast)}.retry-btn:hover{background:var(--color-primary-dark)}.app-footer{display:flex;justify-content:center;align-items:center;gap:.5rem;padding:1rem;font-size:.8125rem;color:var(--color-text-muted);border-top:1px solid var(--color-border);background:var(--color-bg-white)}.footer-link{background:none;border:none;padding:.25rem .5rem;font-size:inherit;color:var(--color-text-secondary);cursor:pointer;transition:color var(--transition-fast)}.footer-link:hover{color:var(--color-primary-light);text-decoration:underline}.footer-separator{color:var(--color-border-dark)}.app-header{position:fixed;top:0;left:0;right:0;height:var(--header-height);display:flex;align-items:center;justify-content:space-between;padding:0 2rem;background:linear-gradient(135deg,var(--color-primary) 0%,var(--color-primary-dark) 100%);color:#fff;box-shadow:var(--shadow-md);z-index:100}.header-left{display:flex;align-items:center;gap:1rem}.sidebar-toggle{width:40px;height:40px;display:flex;align-items:center;justify-content:center;background:#ffffff1a;border:1px solid rgba(255,255,255,.2);border-radius:8px;color:#fff;font-size:.875rem;transition:all var(--transition-fast)}.sidebar-toggle:hover{background:#fff3}.header-title h1{font-size:1.375rem;font-weight:600;margin:0;line-height:1.3}.header-subtitle{font-size:.875rem;opacity:.85;margin:0}.header-right{display:flex;align-items:center;gap:2rem}.header-meta{display:flex;gap:1.5rem}.meta-item{display:flex;align-items:center;gap:.5rem;font-size:.875rem;opacity:.9}.meta-icon{font-size:1rem}.header-selector{position:relative;display:flex;align-items:center}.header-selector-icon{position:absolute;left:10px;font-size:1rem;pointer-events:none;z-index:1}.header-select{-webkit-appearance:none;-moz-appearance:none;appearance:none;background:#ffffff1a;border:1px solid rgba(255,255,255,.2);border-radius:8px;color:#fff;font-size:.875rem;font-family:inherit;padding:.5rem 2rem .5rem 2.25rem;cursor:pointer;transition:all var(--transition-fast);min-width:130px}.header-select:hover{background:#fff3}.header-select:focus{outline:none;box-shadow:0 0 0 2px #ffffff4d}.header-select option{background:var(--color-bg-secondary);color:var(--color-text);padding:.5rem}.header-lang-btn{background:none;border:1px solid var(--color-border, #e2e8f0);border-radius:6px;padding:.25rem .5rem;font-size:1.1rem;cursor:pointer;line-height:1;transition:border-color .15s}.header-lang-btn:hover{border-color:var(--color-text-secondary, #94a3b8)}.progress-container{display:flex;flex-direction:column;align-items:flex-end;gap:.375rem}.progress-bar{width:180px;height:6px;background:#fff3;border-radius:3px;overflow:hidden}.progress-fill{height:100%;background:var(--color-accent);border-radius:3px;transition:width var(--transition-normal)}.progress-text{font-size:.75rem;opacity:.85}@media(max-width:1024px){.header-meta{display:none}}@media(max-width:768px){.app-header{padding:0 .75rem}.header-left,.header-right{gap:.5rem}.sidebar-toggle{width:44px;height:44px}.header-select{min-height:44px;min-width:110px;font-size:.8125rem;padding:.5rem 1.5rem .5rem 2rem}.header-title h1{font-size:1rem;max-width:140px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.header-subtitle{display:none}.progress-bar{width:80px}.progress-text{font-size:.6875rem}}@media(max-width:480px){.header-title h1{max-width:100px;font-size:.9375rem}.progress-container{display:none}}.sidebar-backdrop{display:none}@media(max-width:1024px){.sidebar-backdrop{display:block;position:fixed;top:0;right:0;bottom:0;left:0;top:var(--header-height);background:#00000080;z-index:35;animation:fadeIn var(--transition-fast)}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}}.sidebar{position:fixed;top:var(--header-height);left:0;bottom:0;width:var(--sidebar-width);background:var(--color-bg-white);border-right:1px solid var(--color-border);overflow-y:auto;transition:transform var(--transition-normal);z-index:40}.sidebar.closed{transform:translate(-100%)}.sidebar-controls{display:flex;gap:.5rem;padding:.75rem 1rem;border-bottom:1px solid var(--color-border)}.sidebar-control-btn{padding:.375rem .625rem;border:1px solid var(--color-border);border-radius:4px;background:var(--color-bg-white);color:var(--color-text-secondary);font-size:.875rem;cursor:pointer;transition:all var(--transition-fast)}.sidebar-control-btn:hover{background:var(--color-bg-secondary);color:var(--color-text);border-color:var(--color-text-muted)}.sidebar-nav{padding:.5rem 0}.nav-list{list-style:none}.nav-item{margin:0}.nav-item.depth-0>.nav-link,.nav-item.depth-0>.nav-link-row,.nav-item.depth-0>.nav-group{padding-left:1rem}.nav-item.depth-1>.nav-link,.nav-item.depth-1>.nav-link-row,.nav-item.depth-1>.nav-group{padding-left:2rem}.nav-item.depth-2>.nav-link,.nav-item.depth-2>.nav-link-row,.nav-item.depth-2>.nav-group{padding-left:3rem}.nav-item.depth-3>.nav-link,.nav-item.depth-3>.nav-link-row,.nav-item.depth-3>.nav-group{padding-left:4rem}.nav-link-row{display:flex;align-items:center}.nav-expand-toggle{flex-shrink:0;display:flex;align-items:center;justify-content:center;width:1rem;margin-left:-1rem;height:1.5rem;border:none;background:none;font-size:.75rem;color:var(--color-text-muted);cursor:pointer;transition:transform var(--transition-fast);padding:0}.nav-expand-toggle:hover{color:var(--color-text)}.nav-expand-toggle.expanded{transform:rotate(90deg)}.nav-link{display:flex;align-items:center;gap:.75rem;width:100%;padding:.625rem 1rem;border:none;background:none;font-size:.9375rem;color:var(--color-text);text-align:left;cursor:pointer;transition:all var(--transition-fast)}.nav-link:hover{background:var(--color-bg-secondary)}.nav-link.active{background:linear-gradient(90deg,rgba(59,130,246,.1) 0%,transparent 100%);color:var(--color-primary-light);font-weight:500}.nav-link.completed,.nav-link.completed .nav-status{color:var(--color-accent)}.nav-status{flex-shrink:0;width:1.25rem;font-size:.75rem;color:var(--color-text-muted)}.nav-title{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.nav-bookmark{flex-shrink:0;color:#f59e0b;font-size:.875rem}.nav-group{display:flex;align-items:center;gap:.5rem;width:100%;padding:.75rem 1rem;border:none;background:none;font-size:.8125rem;font-weight:600;color:var(--color-text-secondary);text-transform:uppercase;letter-spacing:.025em;cursor:pointer;text-align:left;transition:all var(--transition-fast)}.nav-group:hover{background:var(--color-bg-secondary);color:var(--color-text)}.nav-group-arrow{font-size:.75rem;transition:transform var(--transition-fast);color:var(--color-text-muted)}.nav-group-arrow.expanded{transform:rotate(90deg)}.nav-children{border-left:2px solid var(--color-border);margin-left:1.5rem}@media(max-width:1024px){.sidebar{box-shadow:var(--shadow-lg)}}@media(max-width:768px){.nav-link{padding:.75rem 1rem;min-height:44px}.nav-group{padding:.875rem 1rem;min-height:44px}.sidebar-control-btn{padding:.5rem .75rem;min-height:44px;font-size:1rem}.sidebar-controls{padding:.5rem}}@media(max-width:480px){.sidebar{width:100%}}*{margin:0;padding:0;box-sizing:border-box}:root{--color-primary: #1e3a8a;--color-primary-light: #3b82f6;--color-primary-dark: #1e40af;--color-accent: #10b981;--color-accent-light: #34d399;--color-bg: #f8fafc;--color-bg-secondary: #f1f5f9;--color-bg-white: #ffffff;--color-text: #1e293b;--color-text-secondary: #64748b;--color-text-muted: #94a3b8;--color-border: #e2e8f0;--color-border-dark: #cbd5e1;--font-sans: "Inter", system-ui, -apple-system, sans-serif;--font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;--header-height: 80px;--sidebar-width: 320px;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .05);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .1);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .1);--transition-fast: .15s ease;--transition-normal: .25s ease}[data-theme=dark]{--color-primary: #3b82f6;--color-primary-light: #60a5fa;--color-primary-dark: #2563eb;--color-accent: #34d399;--color-accent-light: #6ee7b7;--color-bg: #0f172a;--color-bg-secondary: #1e293b;--color-bg-white: #1e293b;--color-text: #f1f5f9;--color-text-secondary: #94a3b8;--color-text-muted: #64748b;--color-border: #334155;--color-border-dark: #475569;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .4)}[data-theme=ocean]{--color-primary: #0891b2;--color-primary-light: #22d3ee;--color-primary-dark: #0e7490;--color-accent: #f59e0b;--color-accent-light: #fbbf24;--color-bg: #ecfeff;--color-bg-secondary: #cffafe;--color-bg-white: #ffffff;--color-text: #164e63;--color-text-secondary: #0e7490;--color-text-muted: #67e8f9;--color-border: #a5f3fc;--color-border-dark: #67e8f9}[data-theme=ocean-dark]{--color-primary: #22d3ee;--color-primary-light: #67e8f9;--color-primary-dark: #06b6d4;--color-accent: #fbbf24;--color-accent-light: #fcd34d;--color-bg: #083344;--color-bg-secondary: #164e63;--color-bg-white: #155e75;--color-text: #ecfeff;--color-text-secondary: #a5f3fc;--color-text-muted: #67e8f9;--color-border: #0e7490;--color-border-dark: #0891b2;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .4)}[data-theme=forest]{--color-primary: #059669;--color-primary-light: #10b981;--color-primary-dark: #047857;--color-accent: #d97706;--color-accent-light: #f59e0b;--color-bg: #ecfdf5;--color-bg-secondary: #d1fae5;--color-bg-white: #ffffff;--color-text: #064e3b;--color-text-secondary: #047857;--color-text-muted: #6ee7b7;--color-border: #a7f3d0;--color-border-dark: #6ee7b7}[data-theme=forest-dark]{--color-primary: #10b981;--color-primary-light: #34d399;--color-primary-dark: #059669;--color-accent: #f59e0b;--color-accent-light: #fbbf24;--color-bg: #022c22;--color-bg-secondary: #064e3b;--color-bg-white: #065f46;--color-text: #ecfdf5;--color-text-secondary: #a7f3d0;--color-text-muted: #6ee7b7;--color-border: #047857;--color-border-dark: #059669;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .4)}[data-theme=sunset]{--color-primary: #ea580c;--color-primary-light: #f97316;--color-primary-dark: #c2410c;--color-accent: #0891b2;--color-accent-light: #22d3ee;--color-bg: #fff7ed;--color-bg-secondary: #ffedd5;--color-bg-white: #ffffff;--color-text: #7c2d12;--color-text-secondary: #c2410c;--color-text-muted: #fdba74;--color-border: #fed7aa;--color-border-dark: #fdba74}[data-theme=sunset-dark]{--color-primary: #f97316;--color-primary-light: #fb923c;--color-primary-dark: #ea580c;--color-accent: #22d3ee;--color-accent-light: #67e8f9;--color-bg: #431407;--color-bg-secondary: #7c2d12;--color-bg-white: #9a3412;--color-text: #fff7ed;--color-text-secondary: #fed7aa;--color-text-muted: #fdba74;--color-border: #c2410c;--color-border-dark: #ea580c;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .4)}[data-theme=lavender]{--color-primary: #7c3aed;--color-primary-light: #8b5cf6;--color-primary-dark: #6d28d9;--color-accent: #059669;--color-accent-light: #10b981;--color-bg: #f5f3ff;--color-bg-secondary: #ede9fe;--color-bg-white: #ffffff;--color-text: #4c1d95;--color-text-secondary: #6d28d9;--color-text-muted: #c4b5fd;--color-border: #ddd6fe;--color-border-dark: #c4b5fd}[data-theme=lavender-dark]{--color-primary: #8b5cf6;--color-primary-light: #a78bfa;--color-primary-dark: #7c3aed;--color-accent: #10b981;--color-accent-light: #34d399;--color-bg: #2e1065;--color-bg-secondary: #4c1d95;--color-bg-white: #5b21b6;--color-text: #f5f3ff;--color-text-secondary: #ddd6fe;--color-text-muted: #c4b5fd;--color-border: #6d28d9;--color-border-dark: #7c3aed;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .4)}html{font-size:16px;scroll-behavior:smooth}body{font-family:var(--font-sans);color:var(--color-text);background:var(--color-bg);line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--color-bg-secondary)}::-webkit-scrollbar-thumb{background:var(--color-border-dark);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--color-text-muted)}::selection{background:var(--color-primary-light);color:#fff}a{color:var(--color-primary-light);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--color-primary);text-decoration:underline}button{font-family:inherit;cursor:pointer}button:disabled{cursor:not-allowed;opacity:.5}code{font-family:var(--font-mono)}kbd{display:inline-block;padding:2px 6px;font-family:var(--font-mono);font-size:.75rem;background:var(--color-bg-secondary);border:1px solid var(--color-border);border-radius:4px;box-shadow:0 1px 1px #0000001a}.tag{display:inline-block;padding:2px 10px;font-size:.75rem;font-weight:500;background:var(--color-bg-secondary);border-radius:9999px;color:var(--color-text-secondary)}@media(max-width:768px){:root{--header-height: 60px;--sidebar-width: 280px}}@media(max-width:480px){:root{--sidebar-width: 100%}}.app{min-height:100vh;display:flex;flex-direction:column}.app-body{display:flex;flex:1;margin-top:var(--header-height)}.app-main{flex:1;min-width:0;padding:2rem 3rem;transition:margin-left var(--transition-normal)}.chapter-loading-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--bg-primary, #fff);opacity:.7;z-index:100}.chapter-loading-spinner{position:fixed;top:calc(50% - 16px);left:calc(50% - 16px);width:32px;height:32px;border:3px solid var(--border-color, #e2e8f0);border-top-color:var(--accent-color, #3182ce);border-radius:50%;animation:chapter-spin .6s linear infinite;z-index:101}@keyframes chapter-spin{to{transform:rotate(360deg)}}.app.sidebar-open .app-main{margin-left:var(--sidebar-width)}.app.sidebar-closed .app-main{margin-left:0}@media(max-width:1024px){.app.sidebar-open .app-main{margin-left:0}.app.sidebar-open .sidebar{position:fixed;z-index:50;box-shadow:var(--shadow-lg)}}@media(max-width:768px){.app-main{padding:1rem}}@media(max-width:480px){.app-main{padding:.75rem}}