:root{--color-bg: #faf8f5;--color-bg-sidebar: #1a1612;--color-text: #1a1612;--color-text-secondary: #6b5d52;--color-text-light: rgba(255, 255, 255, .95);--color-text-muted: rgba(255, 255, 255, .65);--color-accent: #D97757;--color-accent-light: #e8956f;--color-border: #e5ddd4;--color-code-bg: #f5f0eb;--font-serif: "Noto Serif SC", "Songti SC", serif;--font-sans: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;--sidebar-width: 300px;--topbar-height: 56px;--content-max-width: 720px;--spacing-xs: 4px;--spacing-sm: 8px;--spacing-md: 16px;--spacing-lg: 24px;--spacing-xl: 32px;--spacing-xxl: 48px;--transition: .2s ease}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:16px;-webkit-text-size-adjust:100%}body{font-family:var(--font-sans);background:var(--color-bg);color:var(--color-text);line-height:1.6;min-height:100vh;overflow-x:hidden}.app{display:flex;min-height:100vh}.sidebar{position:fixed;left:0;top:0;bottom:0;width:var(--sidebar-width);background:var(--color-bg-sidebar);color:var(--color-text-light);display:flex;flex-direction:column;z-index:100;transform:translate(-100%);transition:transform var(--transition)}.sidebar.open{transform:translate(0)}.sidebar-header{padding:var(--spacing-lg);border-bottom:1px solid rgba(255,255,255,.1);display:flex;justify-content:space-between;align-items:flex-start}.sidebar-brand{text-decoration:none;color:inherit}.brand-zh{display:block;font-family:var(--font-serif);font-size:1.5rem;font-weight:700;color:var(--color-text-light)}.brand-en{display:block;font-size:.75rem;color:var(--color-text-muted);margin-top:var(--spacing-xs)}.close-btn{background:none;border:none;color:var(--color-text-muted);cursor:pointer;padding:var(--spacing-sm);margin:calc(-1 * var(--spacing-sm))}.close-btn:hover{color:var(--color-text-light)}.sidebar-nav{flex:1;overflow-y:auto;padding:var(--spacing-md) 0}.part-header{padding:var(--spacing-md) var(--spacing-lg);font-size:.7rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--color-accent);margin-top:var(--spacing-md)}.part-header:first-child{margin-top:0}.nav-item{display:flex;align-items:flex-start;gap:var(--spacing-sm);padding:var(--spacing-sm) var(--spacing-lg);text-decoration:none;color:var(--color-text-muted);transition:all var(--transition);font-size:.875rem}.nav-item:hover{color:var(--color-text-light);background:#ffffff0d}.nav-item.active{color:var(--color-text-light);background:#d9775740;border-left:3px solid var(--color-accent)}.nav-number{flex-shrink:0;width:24px;font-weight:500;color:var(--color-text-muted)}.nav-title{flex:1}.overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000080;z-index:99;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px)}.main-content{flex:1;min-width:0}.top-bar{position:sticky;top:0;height:var(--topbar-height);background:var(--color-bg);border-bottom:1px solid var(--color-border);display:flex;align-items:center;padding:0 var(--spacing-md);z-index:50}.menu-btn{background:none;border:none;color:var(--color-text);cursor:pointer;padding:var(--spacing-sm);margin-left:calc(-1 * var(--spacing-sm));display:flex;align-items:center;justify-content:center}.top-title{flex:1;text-align:center;font-family:var(--font-serif);font-size:1.125rem;font-weight:600}.top-spacer{width:40px}.content-wrapper{padding:var(--spacing-lg)}.toc{max-width:var(--content-max-width);margin:0 auto}.toc-header{text-align:center;margin-bottom:var(--spacing-xxl);padding-bottom:var(--spacing-xl);border-bottom:1px solid var(--color-border)}.toc-title{font-family:var(--font-serif);font-size:2.5rem;font-weight:700;color:var(--color-text);margin-bottom:var(--spacing-sm)}.toc-subtitle{font-size:1.25rem;color:var(--color-accent);font-weight:500;margin-bottom:var(--spacing-sm)}.toc-desc{color:var(--color-text-secondary);font-size:.95rem}.toc-parts{display:flex;flex-direction:column;gap:var(--spacing-xl)}.toc-part{background:#fff;border-radius:12px;padding:var(--spacing-lg);box-shadow:0 1px 3px #00000014}.part-title{margin-bottom:var(--spacing-md);padding-bottom:var(--spacing-md);border-bottom:1px solid var(--color-border)}.part-title-zh{display:block;font-family:var(--font-serif);font-size:1.125rem;font-weight:600;color:var(--color-text)}.part-title-en{display:block;font-size:.8rem;color:var(--color-text-secondary);margin-top:var(--spacing-xs)}.part-chapters{list-style:none}.chapter-link{display:flex;align-items:baseline;gap:var(--spacing-md);padding:var(--spacing-sm) 0;text-decoration:none;color:var(--color-text);transition:color var(--transition)}.chapter-link:hover{color:var(--color-accent)}.chapter-number{flex-shrink:0;font-size:.8rem;color:var(--color-text-secondary);min-width:48px}.chapter-title{font-size:.95rem}.chapter{max-width:var(--content-max-width);margin:0 auto}.chapter-content{background:#fff;border-radius:12px;padding:var(--spacing-xl);box-shadow:0 1px 3px #00000014}.chapter-content h1{font-family:var(--font-serif);font-size:1.75rem;font-weight:700;margin-bottom:var(--spacing-lg);color:var(--color-text);line-height:1.3}.chapter-content h2{font-family:var(--font-serif);font-size:1.35rem;font-weight:600;margin-top:var(--spacing-xl);margin-bottom:var(--spacing-md);color:var(--color-text);padding-bottom:var(--spacing-sm);border-bottom:2px solid var(--color-accent)}.chapter-content h3{font-size:1.1rem;font-weight:600;margin-top:var(--spacing-lg);margin-bottom:var(--spacing-sm);color:var(--color-text)}.chapter-content h4{font-size:1rem;font-weight:600;margin-top:var(--spacing-md);margin-bottom:var(--spacing-sm);color:var(--color-accent)}.chapter-content p{margin-bottom:var(--spacing-md);line-height:1.8}.chapter-content ul,.chapter-content ol{margin-bottom:var(--spacing-md);padding-left:var(--spacing-lg)}.chapter-content li{margin-bottom:var(--spacing-sm);line-height:1.7}.chapter-content blockquote{margin:var(--spacing-md) 0;padding:var(--spacing-md) var(--spacing-lg);background:linear-gradient(135deg,#f8f9fa,#f0f4f8);border-left:4px solid var(--color-accent);border-radius:0 8px 8px 0;font-style:normal}.chapter-content blockquote p{margin-bottom:0}.chapter-content blockquote p+p{margin-top:var(--spacing-sm)}.chapter-content code{background:var(--color-code-bg);padding:2px 6px;border-radius:4px;font-size:.9em;font-family:SF Mono,Fira Code,monospace}.chapter-content pre{background:#282c34;color:#abb2bf;padding:var(--spacing-md);border-radius:8px;overflow-x:auto;margin:var(--spacing-md) 0}.chapter-content pre code{background:none;padding:0;color:inherit}.chapter-content table{width:100%;border-collapse:collapse;margin:var(--spacing-md) 0;font-size:.9rem}.chapter-content th,.chapter-content td{padding:var(--spacing-sm) var(--spacing-md);text-align:left;border-bottom:1px solid var(--color-border)}.chapter-content th{background:var(--color-code-bg);font-weight:600}.chapter-content tr:hover{background:#00000005}.chapter-content strong{font-weight:600;color:var(--color-text)}.chapter-content em{font-style:italic}.chapter-content hr{border:none;height:1px;background:var(--color-border);margin:var(--spacing-xl) 0}.chapter-nav{display:flex;justify-content:space-between;gap:var(--spacing-md);margin-top:var(--spacing-xl);padding-top:var(--spacing-xl);border-top:1px solid var(--color-border)}.nav-btn{display:flex;align-items:center;gap:var(--spacing-sm);padding:var(--spacing-md);background:#fff;border:1px solid var(--color-border);border-radius:8px;cursor:pointer;transition:all var(--transition);max-width:45%}.nav-btn:hover{border-color:var(--color-accent);box-shadow:0 2px 8px #d9775726}.nav-btn.prev{text-align:left}.nav-btn.next{text-align:right;margin-left:auto}.nav-btn-text{display:flex;flex-direction:column;gap:2px;overflow:hidden}.nav-btn-label{font-size:.75rem;color:var(--color-text-secondary)}.nav-btn-title{font-size:.875rem;font-weight:500;color:var(--color-text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.loading{display:flex;justify-content:center;align-items:center;min-height:200px}.loading-spinner{width:32px;height:32px;border:3px solid var(--color-border);border-top-color:var(--color-accent);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}@media (min-width: 769px){.sidebar{transform:translate(0)}.main-content{margin-left:var(--sidebar-width)}.menu-btn{display:none}.top-title{text-align:left;padding-left:var(--spacing-sm)}.top-spacer,.overlay,.close-btn{display:none}.content-wrapper{padding:var(--spacing-xl) var(--spacing-xxl)}.toc-title{font-size:3rem}.chapter-content{padding:var(--spacing-xxl)}.chapter-content h1{font-size:2rem}}@media (max-width: 480px){:root{--sidebar-width: 280px}.content-wrapper{padding:var(--spacing-md)}.chapter-content{padding:var(--spacing-md);border-radius:8px}.chapter-content h1{font-size:1.5rem}.chapter-content h2{font-size:1.2rem}.toc-title{font-size:2rem}.toc-part{padding:var(--spacing-md)}.nav-btn{padding:var(--spacing-sm)}.nav-btn svg{flex-shrink:0}.nav-btn-title{font-size:.8rem}.chapter-content table{display:block;overflow-x:auto}}@media (prefers-color-scheme: dark){:root{--color-bg: #1a1612;--color-text: #f0ebe6;--color-text-secondary: #a89888;--color-border: #3d342c;--color-code-bg: #2a231d}.toc-part,.chapter-content,.nav-btn{background:#252019}.top-bar{background:#1a1612;border-color:#3d342c}.chapter-content blockquote{background:linear-gradient(135deg,#252019,#2a231d)}}