:root{--bg-primary: #f5f5f7;--bg-secondary: #ffffff;--bg-tertiary: #e8e8ed;--text-primary: #1d1d1f;--text-secondary: #86868b;--text-tertiary: #6e6e73;--accent: #0071e3;--accent-hover: #0077ed;--accent-light: rgba(0, 113, 227, .1);--border: rgba(0, 0, 0, .08);--shadow-sm: 0 1px 3px rgba(0, 0, 0, .04);--shadow-md: 0 4px 12px rgba(0, 0, 0, .08);--shadow-lg: 0 12px 40px rgba(0, 0, 0, .12);--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 20px;--transition: all .2s ease;--transition-fast: all .15s ease;--success: #34c759;--error: #ff3b30;--info: #5ac8fa}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,SF Pro Display,SF Pro Text,Helvetica Neue,Arial,sans-serif;background:var(--bg-primary);color:var(--text-primary);line-height:1.5;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.app-container{min-height:100vh;display:flex;flex-direction:column}.main-content{flex:1;padding-top:60px}.navbar{position:fixed;top:0;left:0;right:0;height:52px;background:#ffffffb8;backdrop-filter:saturate(180%) blur(20px);-webkit-backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid var(--border);z-index:100}.navbar-content{max-width:1400px;margin:0 auto;height:100%;padding:0 24px;display:flex;align-items:center;justify-content:space-between}.navbar-brand{display:flex;align-items:center;gap:8px;cursor:pointer;transition:var(--transition)}.navbar-brand:hover{opacity:.7}.brand-icon{font-size:24px}.brand-text{font-size:18px;font-weight:600;color:var(--text-primary)}.navbar-center{display:flex;align-items:center;justify-content:center;flex:1}.online-indicator{display:flex;align-items:center;gap:6px;padding:4px 12px;background:#34c7591a;border-radius:20px;font-size:13px;color:var(--success)}.online-dot{width:8px;height:8px;border-radius:50%;background:var(--success);animation:pulse 2s infinite}@keyframes pulse{0%,to{opacity:1}50%{opacity:.5}}.online-text{font-weight:500}.navbar-actions{display:flex;align-items:center;gap:12px}.btn-primary{display:inline-flex;align-items:center;gap:6px;padding:8px 16px;background:var(--accent);color:#fff;border:none;border-radius:var(--radius-lg);font-size:14px;font-weight:500;cursor:pointer;transition:var(--transition)}.btn-primary:hover{background:var(--accent-hover);transform:scale(1.02)}.btn-primary:disabled{opacity:.5;cursor:not-allowed;transform:none}.btn-secondary{padding:8px 16px;background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border);border-radius:var(--radius-lg);font-size:14px;font-weight:500;cursor:pointer;transition:var(--transition)}.btn-secondary:hover{background:var(--bg-tertiary)}.btn-full{width:100%;justify-content:center;padding:12px 24px}.btn-link{background:none;border:none;color:var(--accent);font-size:14px;font-weight:500;cursor:pointer;transition:var(--transition)}.btn-link:hover{text-decoration:underline}.btn-icon{font-size:14px}.user-avatar{width:32px;height:32px;border-radius:50%;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;font-size:14px;font-weight:600;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:var(--transition)}.user-avatar:hover{transform:scale(1.05)}.user-menu-container{position:relative}.user-menu{position:absolute;top:calc(100% + 8px);right:0;width:220px;background:var(--bg-secondary);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);border:1px solid var(--border);overflow:hidden;animation:fadeIn .15s ease}@keyframes fadeIn{0%{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}.user-menu-header{padding:12px 16px;display:flex;flex-direction:column;gap:2px}.user-menu-username{font-weight:600;color:var(--text-primary)}.user-menu-email{font-size:13px;color:var(--text-secondary)}.user-menu-divider{height:1px;background:var(--border)}.user-menu-item{width:100%;padding:10px 16px;background:none;border:none;text-align:left;font-size:14px;color:var(--text-primary);cursor:pointer;transition:var(--transition)}.user-menu-item:hover{background:var(--bg-tertiary)}.home-layout{max-width:1400px;margin:0 auto;padding:32px 24px;display:grid;grid-template-columns:1fr 320px;gap:24px}.home-main{min-width:0}.home-header{margin-bottom:24px}.home-header h1{font-size:36px;font-weight:700;letter-spacing:-.5px;margin-bottom:4px}.subtitle{font-size:16px;color:var(--text-secondary)}.home-controls{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:20px;flex-wrap:wrap}.sort-tabs-wrapper{display:flex;flex-direction:column;gap:6px}.sort-tabs{display:flex;gap:4px;padding:4px;background:var(--bg-tertiary);border-radius:var(--radius-lg)}.sort-tab{display:flex;align-items:center;gap:6px;padding:8px 16px;background:transparent;border:none;border-radius:var(--radius-md);font-size:14px;font-weight:500;color:var(--text-secondary);cursor:pointer;transition:var(--transition)}.sort-tab.active{background:var(--bg-secondary);color:var(--text-primary);box-shadow:var(--shadow-sm)}.sort-tab:hover:not(.active){color:var(--text-primary)}.tab-icon{font-size:14px}.sort-hint{font-size:12px;color:var(--text-tertiary);padding-left:8px}.search-box{display:flex;align-items:center;gap:8px;padding:8px 14px;background:var(--bg-secondary);border:1px solid var(--border);border-radius:var(--radius-lg);min-width:240px;transition:var(--transition)}.search-box:focus-within{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-light)}.search-icon{font-size:14px;opacity:.5}.search-box input{flex:1;border:none;background:none;font-size:14px;color:var(--text-primary);outline:none}.search-box input::placeholder{color:var(--text-tertiary)}.search-clear{background:none;border:none;color:var(--text-tertiary);cursor:pointer;padding:2px;font-size:12px;opacity:.6;transition:var(--transition)}.search-clear:hover{opacity:1}.post-list{display:flex;flex-direction:column;gap:12px}.post-card{display:flex;gap:12px;background:var(--bg-secondary);border-radius:var(--radius-lg);padding:16px;text-decoration:none;color:inherit;transition:var(--transition);box-shadow:var(--shadow-sm);border:1px solid transparent}.post-card:hover{box-shadow:var(--shadow-md);border-color:var(--border)}.post-vote{display:flex;flex-direction:column;align-items:center;padding:8px 4px;min-width:40px;border-radius:var(--radius-sm);cursor:pointer;transition:var(--transition);-webkit-user-select:none;user-select:none}.post-vote:hover{background:var(--accent-light)}.post-vote.liked{color:var(--accent)}.vote-arrow{font-size:12px;opacity:.6}.vote-count{font-size:14px;font-weight:600}.post-card-body{flex:1;min-width:0}.post-title{font-size:17px;font-weight:600;color:var(--text-primary);line-height:1.4;margin-bottom:6px}.post-preview{font-size:14px;color:var(--text-secondary);line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-bottom:10px}.post-card-footer{display:flex;align-items:center;justify-content:space-between}.post-author{display:flex;align-items:center;gap:8px}.author-avatar{width:22px;height:22px;border-radius:50%;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;font-size:10px;font-weight:600;display:flex;align-items:center;justify-content:center}.author-avatar.large{width:40px;height:40px;font-size:16px}.author-name{font-size:13px;font-weight:500;color:var(--text-primary)}.post-time{font-size:12px;color:var(--text-tertiary)}.post-stats{display:flex;gap:12px}.stat{display:flex;align-items:center;gap:4px;font-size:12px;color:var(--text-secondary)}.stat-icon{font-size:12px}.sidebar{display:flex;flex-direction:column;gap:16px;position:sticky;top:76px;height:fit-content}.sidebar-card{background:var(--bg-secondary);border-radius:var(--radius-lg);padding:16px;box-shadow:var(--shadow-sm)}.sidebar-title{font-size:14px;font-weight:600;color:var(--text-primary);margin-bottom:12px}.stats-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.stat-box{display:flex;flex-direction:column;align-items:center;padding:12px;background:var(--bg-primary);border-radius:var(--radius-md)}.stat-number{font-size:24px;font-weight:700;color:var(--accent)}.stat-label{font-size:12px;color:var(--text-secondary)}.hot-posts{display:flex;flex-direction:column;gap:4px}.hot-post-item{display:flex;align-items:flex-start;gap:10px;padding:10px 8px;text-decoration:none;color:inherit;border-radius:var(--radius-sm);transition:var(--transition)}.hot-post-item:hover{background:var(--bg-primary)}.hot-post-rank{display:flex;align-items:center;justify-content:center;width:20px;height:20px;background:var(--bg-tertiary);border-radius:4px;font-size:11px;font-weight:600;color:var(--text-secondary);flex-shrink:0}.hot-post-item:nth-child(1) .hot-post-rank{background:#ff6b6b;color:#fff}.hot-post-item:nth-child(2) .hot-post-rank{background:#ffa94d;color:#fff}.hot-post-item:nth-child(3) .hot-post-rank{background:#ffd43b;color:#fff}.hot-post-title{font-size:13px;color:var(--text-primary);line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.tips-card{background:linear-gradient(135deg,#667eea15,#764ba215)}.tips-text{font-size:13px;color:var(--text-secondary);line-height:1.5}.ai-credit{background:linear-gradient(135deg,#f0f9ff,#e0f2fe);border:1px solid rgba(59,130,246,.1)}.ai-credit-text{font-size:12px;color:var(--text-secondary);text-align:center;line-height:1.5}.ai-credit-text strong{color:#3b82f6;font-weight:600}.page-loader{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:60vh;gap:16px}.loader-spinner{width:40px;height:40px;border:3px solid var(--bg-tertiary);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.page-loader p{color:var(--text-secondary);font-size:15px}.loading-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:80px 20px;gap:16px}.loading-spinner{width:32px;height:32px;border:3px solid var(--bg-tertiary);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite}.loading-state p{color:var(--text-secondary);font-size:15px}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:80px 20px;text-align:center}.empty-icon{font-size:48px;margin-bottom:16px}.empty-state p{color:var(--text-secondary);font-size:16px}.empty-hint{font-size:14px!important;color:var(--text-tertiary)!important;margin-top:4px}.skeleton{pointer-events:none}.skeleton-vote{display:flex;flex-direction:column;align-items:center;gap:4px;padding:8px 4px}.skeleton-circle{width:24px;height:24px;border-radius:50%;background:linear-gradient(90deg,var(--bg-tertiary) 25%,var(--bg-primary) 50%,var(--bg-tertiary) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite}.skeleton-content{flex:1}.skeleton-title{height:20px;background:linear-gradient(90deg,var(--bg-tertiary) 25%,var(--bg-primary) 50%,var(--bg-tertiary) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite;border-radius:4px;margin-bottom:10px;width:70%}.skeleton-title.large{height:28px;width:60%}.skeleton-text{height:14px;background:linear-gradient(90deg,var(--bg-tertiary) 25%,var(--bg-primary) 50%,var(--bg-tertiary) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite;border-radius:4px;margin-bottom:8px}.skeleton-text.short{width:50%}.skeleton-footer{display:flex;align-items:center;gap:8px;margin-top:10px}.skeleton-avatar{width:22px;height:22px;border-radius:50%;background:linear-gradient(90deg,var(--bg-tertiary) 25%,var(--bg-primary) 50%,var(--bg-tertiary) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite}.skeleton-avatar.small{width:28px;height:28px}.skeleton-name{width:60px;height:12px;background:linear-gradient(90deg,var(--bg-tertiary) 25%,var(--bg-primary) 50%,var(--bg-tertiary) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite;border-radius:4px}.skeleton-name.small{width:80px}.skeleton-meta{display:flex;align-items:center;gap:10px;margin-bottom:20px}.skeleton-body{margin-top:20px}@keyframes shimmer{0%{background-position:200% 0}to{background-position:-200% 0}}.post-detail-page{max-width:800px;margin:0 auto;padding:24px}.back-button{display:inline-flex;align-items:center;gap:4px;padding:8px 12px;background:var(--bg-secondary);border:1px solid var(--border);border-radius:var(--radius-md);font-size:14px;color:var(--text-primary);cursor:pointer;margin-bottom:20px;transition:var(--transition)}.back-button:hover{background:var(--bg-tertiary)}.post-detail-card{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:28px;box-shadow:var(--shadow-sm);margin-bottom:20px}.post-detail-header{margin-bottom:20px}.post-detail-header h1{font-size:26px;font-weight:700;line-height:1.3;margin-bottom:14px}.post-detail-meta{display:flex;align-items:center}.author-info{display:flex;align-items:center;gap:10px}.author-details{display:flex;flex-direction:column;gap:2px}.post-date{font-size:13px;color:var(--text-secondary)}.post-detail-body{font-size:16px;line-height:1.7;color:var(--text-primary);white-space:pre-wrap;word-wrap:break-word;margin-bottom:20px}.post-detail-footer{padding-top:16px;border-top:1px solid var(--border)}.post-stats-large{display:flex;align-items:center;gap:20px}.like-btn{display:inline-flex;align-items:center;gap:6px;padding:8px 16px;background:var(--bg-tertiary);border:none;border-radius:var(--radius-lg);font-size:14px;font-weight:500;cursor:pointer;transition:var(--transition)}.like-btn:hover:not(:disabled){background:#fee2e2}.like-btn.liked{background:#fee2e2;color:#ef4444}.like-btn:disabled{cursor:default}.like-icon{font-size:16px}.stat-item{display:flex;align-items:center;gap:6px;font-size:14px;color:var(--text-secondary)}.comment-section{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:20px;box-shadow:var(--shadow-sm)}.comment-section h2{font-size:18px;font-weight:600;margin-bottom:16px}.comment-input{margin-bottom:20px}.comment-input textarea{width:100%;padding:12px 14px;border:1px solid var(--border);border-radius:var(--radius-md);font-size:14px;font-family:inherit;resize:none;transition:var(--transition);margin-bottom:10px}.comment-input textarea:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-light)}.comment-input textarea::placeholder{color:var(--text-tertiary)}.comment-actions{display:flex;align-items:center;justify-content:space-between}.char-count{font-size:12px;color:var(--text-tertiary)}.no-comments{display:flex;flex-direction:column;align-items:center;padding:40px 20px;color:var(--text-secondary)}.no-comments-icon{font-size:36px;margin-bottom:10px}.comment-list{display:flex;flex-direction:column;gap:12px}.comment-item{padding:14px;background:var(--bg-primary);border-radius:var(--radius-md)}.comment-header{display:flex;align-items:center;gap:8px;margin-bottom:8px}.comment-avatar{width:26px;height:26px;border-radius:50%;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;font-size:11px;font-weight:600;display:flex;align-items:center;justify-content:center}.comment-author{font-size:13px;font-weight:500;color:var(--text-primary)}.comment-time{font-size:12px;color:var(--text-tertiary)}.comment-content{font-size:14px;line-height:1.5;color:var(--text-primary)}.comment-footer{margin-top:8px;display:flex;justify-content:flex-end}.comment-like-btn{display:flex;align-items:center;gap:4px;padding:4px 10px;background:none;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:12px;color:var(--text-secondary);cursor:pointer;transition:var(--transition)}.comment-like-btn:hover{background:var(--bg-tertiary)}.comment-like-btn.liked{background:var(--accent-light);border-color:var(--accent);color:var(--accent)}.error-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:80px 20px;text-align:center}.error-icon{font-size:64px;margin-bottom:16px}.error-state h2{font-size:24px;font-weight:600;margin-bottom:8px}.error-state p{color:var(--text-secondary);margin-bottom:24px}.login-page{min-height:calc(100vh - 60px);display:flex;align-items:center;justify-content:center;padding:40px 24px}.login-card{width:100%;max-width:380px;background:var(--bg-secondary);border-radius:var(--radius-xl);padding:36px;box-shadow:var(--shadow-md)}.login-header{text-align:center;margin-bottom:28px}.login-logo{font-size:48px;margin-bottom:12px;display:block}.login-header h1{font-size:26px;font-weight:700;margin-bottom:6px}.login-header p{color:var(--text-secondary)}.login-form{display:flex;flex-direction:column;gap:14px}.error-message{padding:10px 14px;background:#fef2f2;border:1px solid #fecaca;border-radius:var(--radius-md);color:#dc2626;font-size:13px}.form-group{display:flex;flex-direction:column;gap:6px}.form-group label{font-size:13px;font-weight:500;color:var(--text-primary)}.form-group input,.form-group textarea{padding:10px 14px;border:1px solid var(--border);border-radius:var(--radius-md);font-size:14px;font-family:inherit;transition:var(--transition)}.form-group input:focus,.form-group textarea:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-light)}.form-group input::placeholder,.form-group textarea::placeholder{color:var(--text-tertiary)}.login-footer{margin-top:20px;text-align:center;display:flex;align-items:center;justify-content:center;gap:4px}.login-footer p{color:var(--text-secondary);font-size:14px}.create-post-page{max-width:680px;margin:0 auto;padding:24px}.page-header{display:flex;align-items:center;gap:14px;margin-bottom:24px}.page-header h1{font-size:26px;font-weight:700}.create-post-form{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:28px;box-shadow:var(--shadow-sm)}.create-post-form .form-group{margin-bottom:20px}.create-post-form textarea{resize:vertical;min-height:180px}.form-actions{display:flex;justify-content:flex-end;gap:10px;padding-top:8px}.auth-prompt{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:80px 20px;text-align:center;background:var(--bg-secondary);border-radius:var(--radius-xl)}.auth-prompt h2{font-size:24px;font-weight:600;margin-bottom:8px}.auth-prompt p{color:var(--text-secondary);margin-bottom:24px}.toast-container{position:fixed;bottom:24px;right:24px;display:flex;flex-direction:column;gap:8px;z-index:1000}.toast{display:flex;align-items:center;gap:10px;padding:12px 16px;background:var(--bg-secondary);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);animation:slideIn .3s ease;min-width:200px}@keyframes slideIn{0%{opacity:0;transform:translate(100%)}to{opacity:1;transform:translate(0)}}.toast-icon{width:20px;height:20px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:600}.toast-success .toast-icon{background:var(--success);color:#fff}.toast-error .toast-icon{background:var(--error);color:#fff}.toast-info .toast-icon{background:var(--info);color:#fff}.toast-message{font-size:14px;color:var(--text-primary)}@media(max-width:1024px){.home-layout{grid-template-columns:1fr}.sidebar{display:none}.home-header h1{font-size:32px}}.settings-page{max-width:600px;margin:0 auto;padding:24px}.settings-card{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:28px;box-shadow:var(--shadow-sm)}.settings-section h2{font-size:20px;font-weight:600;margin-bottom:20px}.profile-avatar{display:flex;justify-content:center;margin-bottom:24px}.avatar-large{width:80px;height:80px;border-radius:50%;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;font-size:32px;font-weight:600;display:flex;align-items:center;justify-content:center}.form-hint{font-size:12px;color:var(--text-tertiary);margin-top:4px}.form-group input.disabled{background:var(--bg-tertiary);color:var(--text-secondary);cursor:not-allowed}@media(max-width:768px){.home-controls{flex-direction:column;align-items:stretch}.sort-tabs{justify-content:center}.search-box{min-width:auto}.post-detail-card{padding:20px}.post-detail-header h1{font-size:22px}.post-stats-large{flex-wrap:wrap;gap:12px}.login-card{padding:24px}.toast-container{left:16px;right:16px;bottom:16px}.toast{min-width:auto}.settings-card{padding:20px}}