:root{--ts-primary: #2563eb;--ts-primary-dark: #1d4ed8;--ts-secondary: #64748b;--ts-success: #22c55e;--ts-warning: #f59e0b;--ts-error: #ef4444;--ts-bg: #f8fafc;--ts-card-bg: white;--ts-border: #e2e8f0;--ts-text: #1e293b;--ts-text-light: #64748b;--ts-radius: 12px;--ts-shadow: 0 4px 6px rgba(0, 0, 0, .07);--ts-shadow-hover: 0 10px 20px rgba(0, 0, 0, .1)}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;line-height:1.6;color:var(--ts-text);background:var(--ts-bg)}.container{max-width:1200px;margin:0 auto;padding:0 20px}.ts-header{background:#fff;border-bottom:1px solid var(--ts-border);padding:1.5rem 0;position:sticky;top:0;z-index:100;box-shadow:0 2px 4px #0000000d}.nav-back{margin-bottom:1rem}.back-link{color:var(--ts-primary);text-decoration:none;font-size:.95rem;display:inline-flex;align-items:center;transition:transform .2s}.back-link:hover{transform:translate(-3px)}.ts-header h1{font-size:2rem;font-weight:700;margin:0;background:linear-gradient(135deg,var(--ts-primary) 0%,var(--ts-primary-dark) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.header-desc{color:var(--ts-text-light);font-size:1.1rem;margin-top:.5rem}.ts-main{padding:2rem 0 4rem;min-height:calc(100vh - 200px)}.quick-access{margin-bottom:3rem}.quick-access h2{font-size:1.5rem;margin-bottom:1.5rem;color:var(--ts-text)}.quick-links{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1rem}.quick-link{display:flex;align-items:center;padding:1.2rem;background:#fff;border:2px solid var(--ts-border);border-radius:10px;text-decoration:none;color:inherit;transition:all .3s ease;position:relative;overflow:hidden}.quick-link:before{content:"";position:absolute;top:0;left:0;width:0;height:100%;background:linear-gradient(90deg,#2563eb1a,#2563eb0d);transition:width .3s ease}.quick-link:hover:before{width:100%}.quick-link:hover{border-color:var(--ts-primary);transform:translateY(-2px);box-shadow:var(--ts-shadow-hover)}.quick-link .icon{font-size:1.8rem;margin-right:1rem;flex-shrink:0}.quick-link-content{flex:1;display:flex;flex-direction:column}.quick-link .text{font-weight:600;font-size:1.05rem;color:var(--ts-text)}.quick-link .desc{font-size:.9rem;color:var(--ts-text-light);margin-top:.2rem}.quick-link .badge{position:absolute;top:.8rem;right:.8rem;padding:.25rem .6rem;background:var(--ts-warning);color:#fff;border-radius:6px;font-size:.75rem;font-weight:600;text-transform:uppercase}.quick-link .badge.hot{background:var(--ts-error)}.categories{margin-bottom:3rem}.categories h2{font-size:1.5rem;margin-bottom:1.5rem;color:var(--ts-text)}.category-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(340px,1fr));gap:1.5rem}.category-card{background:#fff;border:1px solid var(--ts-border);border-radius:var(--ts-radius);padding:1.5rem;text-decoration:none;color:inherit;transition:all .3s ease;display:flex;flex-direction:column;position:relative}.category-card:hover{border-color:var(--ts-primary);box-shadow:var(--ts-shadow-hover);transform:translateY(-3px)}.card-header{display:flex;align-items:center;margin-bottom:1.2rem}.category-card .card-icon{font-size:2.5rem;margin-right:1rem}.category-card h3{font-size:1.4rem;color:var(--ts-primary);font-weight:600}.category-card .issue-list{list-style:none;flex:1}.category-card .issue-list li{color:var(--ts-text-light);font-size:.95rem;border-bottom:1px solid var(--ts-bg);position:relative;padding:.5rem 0 .5rem 1.2rem}.category-card .issue-list li:before{content:"•";position:absolute;left:0;color:var(--ts-primary)}.category-card .issue-list li:last-child{border-bottom:none}.card-footer{display:flex;justify-content:space-between;align-items:center;margin-top:1.2rem;padding-top:1rem;border-top:1px solid var(--ts-bg)}.issue-count{color:var(--ts-text-light);font-size:.9rem;font-weight:500}.category-card .arrow{font-size:1.5rem;color:var(--ts-primary);transition:transform .3s ease}.category-card:hover .arrow{transform:translate(5px)}.help-tips{margin-top:3rem}.tip-card{background:linear-gradient(135deg,#eff6ff,#fff);border:1px solid var(--ts-primary);border-radius:var(--ts-radius);padding:1.5rem}.tip-card h3{color:var(--ts-primary);margin-bottom:1rem;font-size:1.2rem}.tip-card p{color:var(--ts-text);margin-bottom:1rem}.tip-card ul{list-style:none;padding-left:0}.tip-card li{padding:.5rem 0 .5rem 1.5rem;position:relative;color:var(--ts-text-light)}.tip-card li:before{content:"→";position:absolute;left:0;color:var(--ts-primary)}.tip-card a{color:var(--ts-primary);text-decoration:none;font-weight:500}.tip-card a:hover{text-decoration:underline}.breadcrumb{font-size:.95rem;color:var(--ts-text-light);margin-bottom:1rem}.breadcrumb a{color:var(--ts-primary);text-decoration:none}.breadcrumb a:hover{text-decoration:underline}.issues-list{display:flex;flex-direction:column;gap:1rem;margin:2rem 0}.issue-item{background:#fff;border:1px solid var(--ts-border);border-radius:10px;padding:1.5rem;text-decoration:none;color:inherit;transition:all .3s ease;position:relative}.issue-item:hover{border-color:var(--ts-primary);box-shadow:var(--ts-shadow-hover);transform:translate(5px)}.issue-title{font-size:1.2rem;font-weight:600;margin-bottom:.5rem;display:flex;align-items:center;color:var(--ts-text)}.issue-title .icon{margin-right:.8rem;font-size:1.4rem}.issue-desc{color:var(--ts-text-light);margin-bottom:1rem;line-height:1.5}.issue-meta{display:flex;gap:1rem;font-size:.9rem}.issue-meta .platform,.issue-meta .difficulty{padding:.3rem .8rem;border-radius:6px;font-weight:500}.issue-meta .platform{background:var(--ts-bg);color:var(--ts-text-light)}.issue-meta .difficulty{background:var(--ts-success);color:#fff}.issue-meta .difficulty.medium{background:var(--ts-warning)}.issue-meta .difficulty.hard{background:var(--ts-error)}.problem-header{margin-bottom:2rem}.problem-header h1{font-size:2rem;margin:1rem 0;color:var(--ts-text)}.problem-info{display:flex;flex-wrap:wrap;gap:2rem;padding:1rem;background:var(--ts-bg);border-radius:10px;margin:1.5rem 0}.info-item{display:flex;align-items:center;gap:.5rem}.info-item .label{color:var(--ts-text-light);font-weight:500}.info-item .value{color:var(--ts-text);font-weight:600}.problem-section{margin:2.5rem 0}.problem-section h2{font-size:1.5rem;margin-bottom:1rem;color:var(--ts-primary)}.problem-section p{color:var(--ts-text);line-height:1.7;margin-bottom:1rem}.problem-section pre{background:#1e293b;color:#e2e8f0;padding:1.2rem;border-radius:10px;overflow-x:auto;margin:1rem 0;font-family:Monaco,Courier New,monospace;font-size:.95rem;line-height:1.5}.problem-section code{background:var(--ts-bg);color:var(--ts-primary);padding:.2rem .4rem;border-radius:4px;font-size:.95rem}.problem-section pre code{background:none;color:inherit;padding:0}.solution-tabs{display:flex;gap:.5rem;margin:1.5rem 0;border-bottom:2px solid var(--ts-border);overflow-x:auto}.tab-btn{padding:.8rem 1.5rem;background:none;border:none;color:var(--ts-text-light);cursor:pointer;font-size:1rem;font-weight:500;transition:all .3s ease;white-space:nowrap}.tab-btn:hover{color:var(--ts-primary);background:var(--ts-bg)}.tab-btn.active{color:var(--ts-primary);border-bottom:3px solid var(--ts-primary);margin-bottom:-2px}.tab-content{display:none;padding:1.5rem 0;animation:fadeIn .3s ease}.tab-content.active{display:block}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.tab-content h3{color:var(--ts-text);margin:1.5rem 0 1rem;font-size:1.2rem}.tab-content ol,.tab-content ul{margin-left:1.5rem;color:var(--ts-text)}.tab-content li{margin:.8rem 0;line-height:1.7}.download-btn{display:inline-block;padding:.8rem 2rem;background:linear-gradient(135deg,var(--ts-primary) 0%,var(--ts-primary-dark) 100%);color:#fff;text-decoration:none;border-radius:8px;font-weight:600;transition:all .3s ease;margin:.5rem 0}.download-btn:hover{transform:translateY(-2px);box-shadow:0 10px 20px #2563eb4d}.related-issues{margin-top:3rem;padding:1.5rem;background:var(--ts-bg);border-radius:var(--ts-radius)}.related-issues h2{margin-bottom:1rem;color:var(--ts-primary)}.related-issues ul{list-style:none}.related-issues li{padding:.7rem 0;border-bottom:1px solid white}.related-issues li:last-child{border-bottom:none}.related-issues a{color:var(--ts-text);text-decoration:none;display:flex;align-items:center;transition:color .3s ease}.related-issues a:before{content:"→";color:var(--ts-primary);margin-right:.8rem;transition:transform .3s ease}.related-issues a:hover{color:var(--ts-primary)}.related-issues a:hover:before{transform:translate(5px)}.ts-footer{background:#fff;border-top:1px solid var(--ts-border);padding:2rem 0;margin-top:4rem;text-align:center}.ts-footer p{color:var(--ts-text-light);font-size:.95rem}.ts-footer a{color:var(--ts-primary);text-decoration:none;margin:0 .5rem}.ts-footer a:hover{text-decoration:underline}@media (max-width: 768px){.ts-header h1{font-size:1.5rem}.header-desc{font-size:1rem}.category-grid,.quick-links{grid-template-columns:1fr}.problem-info{flex-direction:column;gap:1rem}.solution-tabs{flex-wrap:nowrap;overflow-x:auto;-webkit-overflow-scrolling:touch}.tab-btn{padding:.6rem 1rem;font-size:.9rem}.category-card{padding:1.2rem}.quick-link{padding:1rem}.quick-link .icon{font-size:1.5rem}}@media (max-width: 480px){.container{padding:0 15px}.ts-header{padding:1rem 0}.ts-main{padding:1.5rem 0 3rem}.category-card h3{font-size:1.2rem}.card-icon{font-size:2rem}}