:root{--primary-color:#0071e3;--text-primary:#1d1d1f;--text-secondary:#6e6e73;--bg-primary:#fbfbfd;--bg-secondary:#f5f5f7;--border-color:#d2d2d7;--card-bg:#ffffff;--header-height:64px;--sidebar-width:280px;--max-content-width:1200px;--radius-sm:8px;--radius-md:12px;--radius-lg:18px;--shadow-sm:0 1px 3px rgba(0, 0, 0, 0.06);--shadow-md:0 4px 12px rgba(0, 0, 0, 0.08);--shadow-lg:0 8px 24px rgba(0, 0, 0, 0.12);--transition:all 0.3s cubic-bezier(0.4, 0, 0.2, 1)}@media (prefers-color-scheme:dark){:root{--primary-color:#0a84ff;--text-primary:#f5f5f7;--text-secondary:#a1a1a6;--bg-primary:#000000;--bg-secondary:#1c1c1e;--border-color:#38383d;--card-bg:#1c1c1e}}*{margin:0;padding:0;box-sizing:border-box}html{font-size:16px;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;scroll-behavior:smooth}body{font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;font-size:1rem;line-height:1.75;color:var(--text-primary);background-color:var(--bg-primary);min-height:100vh}.container{max-width:var(--max-content-width);margin:0 auto;padding:0 24px}h1,h2,h3,h4,h5,h6{font-weight:600;line-height:1.2;margin-top:2rem;margin-bottom:1rem;color:var(--text-primary)}h1{font-size:3rem;font-weight:700;letter-spacing:-.02em;margin-top:0}h2{font-size:2.25rem;letter-spacing:-.016em}h3{font-size:1.75rem;letter-spacing:-.012em}h4{font-size:1.375rem}h5{font-size:1.125rem}h6{font-size:1rem}p{margin-bottom:1.5rem}a{color:var(--primary-color);text-decoration:none;transition:var(--transition)}a:hover{text-decoration:underline}.header{position:sticky;top:0;z-index:1000;background:rgba(251,251,253,.8);backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid var(--border-color);height:var(--header-height)}@media (prefers-color-scheme:dark){.header{background:rgba(0,0,0,.8)}}.header-container{display:flex;align-items:center;justify-content:space-between;height:100%}.logo{font-size:1.5rem;font-weight:700;color:var(--text-primary);letter-spacing:-.02em}.nav{display:flex;gap:2rem;align-items:center}.nav-link{color:var(--text-primary);font-weight:500;font-size:.875rem;transition:var(--transition)}.nav-link:hover{color:var(--primary-color);text-decoration:none}.search-container{position:relative;width:280px}.search-input{width:100%;padding:8px 16px 8px 40px;border:1px solid var(--border-color);border-radius:var(--radius-sm);background-color:var(--bg-secondary);font-size:.875rem;transition:var(--transition)}.search-input:focus{outline:0;border-color:var(--primary-color);background-color:var(--card-bg)}.search-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);width:16px;height:16px;opacity:.5}.hero{padding:80px 0;text-align:center;background:linear-gradient(180deg,var(--bg-primary) 0,var(--bg-secondary) 100%)}.hero-title{font-size:4rem;font-weight:700;letter-spacing:-.03em;margin-bottom:1rem;background:linear-gradient(135deg,#0071e3 0,#00c6fb 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.hero-subtitle{font-size:1.5rem;color:var(--text-secondary);font-weight:500;margin-bottom:2rem}.cards-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px;margin:40px 0}.card{background:var(--card-bg);border-radius:var(--radius-md);padding:32px;box-shadow:var(--shadow-sm);transition:var(--transition);border:1px solid var(--border-color);display:flex;flex-direction:column}.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}.card-link{text-decoration:none;color:inherit;display:block}.card-link:hover{text-decoration:none}.card-icon{width:48px;height:48px;margin-bottom:16px;background:var(--primary-color);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;color:#fff;font-size:24px}.card-title{font-size:1.25rem;font-weight:600;margin-bottom:8px;color:var(--text-primary)}.card-description{color:var(--text-secondary);font-size:.875rem;line-height:1.5}.content-wrapper{display:grid;grid-template-columns:var(--sidebar-width) 1fr;gap:40px;max-width:var(--max-content-width);margin:40px auto;padding:0 24px}.sidebar{position:sticky;top:calc(var(--header-height) + 24px);height:fit-content;max-height:calc(100vh - var(--header-height) - 48px);overflow-y:auto}.sidebar-section{margin-bottom:32px}.sidebar-title{font-size:.75rem;font-weight:600;color:var(--text-secondary);text-transform:uppercase;letter-spacing:.05em;margin-bottom:12px}.sidebar-nav{list-style:none}.sidebar-nav-item{margin-bottom:4px}.sidebar-nav-link{display:block;padding:8px 16px;color:var(--text-primary);font-size:.875rem;border-radius:var(--radius-sm);transition:var(--transition)}.sidebar-nav-link:hover{background-color:var(--bg-secondary);text-decoration:none}.sidebar-nav-link.active{background-color:var(--primary-color);color:#fff}.article{max-width:680px}.article-header{margin-bottom:40px}.article-meta{display:flex;gap:16px;font-size:.875rem;color:var(--text-secondary);margin-bottom:16px}.reading-time{display:flex;align-items:center;gap:4px}pre{background-color:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-sm);padding:20px;overflow-x:auto;margin-bottom:1.5rem;position:relative}code{font-family:"SF 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var(--border-color)}th{font-weight:600;background-color:var(--bg-secondary)}.breadcrumbs{display:flex;align-items:center;gap:8px;font-size:.875rem;color:var(--text-secondary);margin-bottom:24px}.breadcrumb-separator{opacity:.5}.footer{margin-top:80px;padding:40px 0;border-top:1px solid var(--border-color);background-color:var(--bg-secondary)}.footer-content{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:40px}.footer-section h4{font-size:.875rem;font-weight:600;margin-bottom:16px}.footer-links{list-style:none}.footer-links li{margin-bottom:8px}.footer-links a{color:var(--text-secondary);font-size:.875rem}.footer-bottom{margin-top:40px;padding-top:24px;border-top:1px solid var(--border-color);text-align:center;font-size:.75rem;color:var(--text-secondary)}.skip-link{position:absolute;top:-40px;left:0;background:var(--primary-color);color:#fff;padding:8px 16px;border-radius:var(--radius-sm);text-decoration:none}.skip-link:focus{top:8px;left:8px;z-index:2000}@media (max-width:768px){.hero-title{font-size:2.5rem}.hero-subtitle{font-size:1.125rem}.content-wrapper{grid-template-columns:1fr}.sidebar{position:static;order:-1;border-bottom:1px solid var(--border-color);padding-bottom:24px;margin-bottom:24px}.nav{display:none}.search-container{width:200px}h1{font-size:2rem}h2{font-size:1.5rem}h3{font-size:1.25rem}}.loading{display:inline-block;width:20px;height:20px;border:3px solid var(--border-color);border-radius:50%;border-top-color:var(--primary-color);animation:spin 1s ease-in-out infinite}@keyframes spin{to{transform:rotate(360deg)}}.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}:focus{outline:2px solid var(--primary-color);outline-offset:2px}.dark-mode{--primary-color:#0a84ff;--text-primary:#f5f5f7;--text-secondary:#a1a1a6;--bg-primary:#000000;--bg-secondary:#1c1c1e;--border-color:#38383d;--card-bg:#1c1c1e}.dark-mode .header{background:rgba(0,0,0,.8)}.dark-mode-toggle{background:0 0;border:none;font-size:1.25rem;cursor:pointer;padding:4px}.search-results{position:absolute;top:100%;left:0;right:0;margin-top:8px;background:var(--card-bg);border:1px solid var(--border-color);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);max-height:400px;overflow-y:auto;display:none;z-index:100}.search-results.active{display:block}.search-result{display:block;padding:16px;border-bottom:1px solid var(--border-color);transition:var(--transition)}.search-result:last-child{border-bottom:none}.search-result:hover{background-color:var(--bg-secondary);text-decoration:none}.search-result-title{font-weight:600;color:var(--text-primary);margin-bottom:4px}.search-result-snippet{font-size:.875rem;color:var(--text-secondary);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.search-no-results{padding:24px;text-align:center;color:var(--text-secondary)}mark{background-color:rgba(255,235,59,.4);padding:0 2px;border-radius:2px}.code-block-wrapper{position:relative;margin-bottom:1.5rem}.code-block-wrapper .copy-button{position:absolute;top:12px;right:12px;z-index:10}.reading-progress{position:fixed;top:0;left:0;height:3px;background:var(--primary-color);width:0;transition:width .1s ease-out;z-index:1001}.article-toc{margin-top:32px;padding:20px;background:var(--bg-secondary);border-radius:var(--radius-md);border:1px solid var(--border-color)}.article-toc h4{font-size:.875rem;font-weight:600;margin:0 0 12px 0;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}.article-toc ul{list-style:none;padding:0}.article-toc li{margin-bottom:8px}.article-toc a{color:var(--text-primary);font-size:.875rem;display:block;padding:4px 0}.article-toc ul ul{margin-left:16px;margin-top:8px}.chapter-nav{display:flex;justify-content:space-between;margin-top:48px;padding-top:24px;border-top:1px solid var(--border-color)}.chapter-nav a{display:flex;align-items:center;gap:8px;font-weight:500}.prev-chapter{margin-right:auto}.next-chapter{margin-left:auto}.mobile-menu-toggle{display:none;background:0 0;border:none;font-size:1.5rem;cursor:pointer;padding:8px}@media (max-width:768px){.mobile-menu-toggle{display:block}.nav{position:fixed;top:var(--header-height);left:-100%;width:280px;height:calc(100vh - var(--header-height));background:var(--card-bg);border-right:1px solid var(--border-color);flex-direction:column;align-items:flex-start;padding:24px;transition:left .3s ease;z-index:999}.menu-open .nav{left:0}.menu-open::after{content:'';position:fixed;top:var(--header-height);left:0;right:0;bottom:0;background:rgba(0,0,0,.5);z-index:998}}.hero-search{max-width:600px;margin:0 auto}.hero-search-input{width:100%;padding:16px 24px;font-size:1.125rem;border:2px solid var(--border-color);border-radius:var(--radius-lg);background:var(--card-bg);box-shadow:var(--shadow-md)}.hero-search-input:focus{border-color:var(--primary-color);box-shadow:0 0 0 4px rgba(0,113,227,.1)}.card-books{margin-top:12px;display:flex;flex-direction:column;gap:8px}.book-preview{font-size:.813rem;color:var(--text-secondary);display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.card-action{margin-top:auto;padding-top:16px;font-weight:500;color:var(--primary-color)}.books-list{display:flex;flex-direction:column;gap:24px;margin-top:32px}.book-item{background:var(--card-bg);padding:24px;border-radius:var(--radius-md);border:1px solid var(--border-color);transition:var(--transition)}.book-item:hover{box-shadow:var(--shadow-sm)}.book-item h2{margin:0 0 8px 0;font-size:1.25rem}.book-meta{color:var(--text-secondary);font-size:.875rem;margin:0}.category-section{margin-bottom:48px}.category-section h2{margin-bottom:24px}.books-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}.book-card{background:var(--card-bg);padding:20px;border-radius:var(--radius-sm);border:1px solid var(--border-color);transition:var(--transition)}.book-card:hover{box-shadow:var(--shadow-sm);transform:translateY(-2px)}.book-card h3{margin:0 0 8px 0;font-size:1.125rem;font-weight:600}.book-card a{color:var(--text-primary)}@media print{.breadcrumbs,.chapter-nav,.dark-mode-toggle,.footer,.header,.mobile-menu-toggle,.reading-progress,.search-container,.sidebar{display:none}.content-wrapper{grid-template-columns:1fr}.article{max-width:100%}pre{white-space:pre-wrap;word-break:break-word}}