*{margin:0;padding:0;box-sizing:border-box}body{font-family:"Microsoft YaHei","PingFang SC","Helvetica Neue",Arial,sans-serif;line-height:1.6;color:#333;background-color:#f5f7fa}a{color:#06c;text-decoration:none;transition:color .3s ease}a:hover{color:#049}img{max-width:100%;height:auto;display:block}:root{--primary-color:#2c5aa0;--secondary-color:#e63946;--bg-dark:#1a2332;--bg-light:#fff;--text-dark:#1a2332;--text-light:#fff;--border-color:#e0e6ed;--shadow-light:0 2px 8px rgba(0,0,0,.08);--shadow-hover:0 4px 16px rgba(0,0,0,.12)}nav{background-color:var(--bg-dark);padding:.8rem 1rem;position:sticky;top:0;z-index:1000;box-shadow:var(--shadow-light)}nav .nav-container{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;flex-wrap:nowrap}nav .logo{font-size:1.5rem;font-weight:700;color:var(--text-light);white-space:nowrap;margin-right:2rem}nav .nav-menu{display:flex;list-style:none;gap:1.5rem;align-items:center;flex-wrap:nowrap;flex:1;justify-content:flex-end}nav .nav-menu li{flex-shrink:0}nav .nav-menu a{color:var(--text-light);font-size:1rem;padding:.5rem 1rem;border-radius:6px;transition:all .3s ease;display:block;white-space:nowrap}nav .nav-menu a:hover{background-color:var(--primary-color);color:var(--text-light)}@media (max-width:768px){nav .nav-container{flex-wrap:nowrap}nav .logo{font-size:1.2rem;margin-right:.5rem}nav .nav-menu{gap:0;flex:1;min-width:0;overflow:hidden}nav .nav-menu li{flex:1 1 0;min-width:0}nav .nav-menu a{font-size:.85rem;padding:.5rem .3rem;text-align:center;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}}.breadcrumb{padding:1rem;margin:1rem auto;max-width:1200px;font-size:.9rem;color:#666}.breadcrumb a{color:var(--primary-color);margin:0 .3rem}.breadcrumb span{margin:0 .3rem}main{max-width:1200px;margin:2rem auto;padding:0 1rem}h1{font-size:2rem;font-weight:700;color:var(--text-dark);margin-bottom:1.5rem;line-height:1.3}h2{font-size:1.5rem;font-weight:600;color:var(--text-dark);margin:2rem 0 1rem}h3{font-size:1.2rem;font-weight:600;color:var(--text-dark);margin:1.5rem 0 1rem}section{background:var(--bg-light);border-radius:12px;padding:2rem;margin-bottom:2rem;box-shadow:var(--shadow-light)}.intro{line-height:1.8;color:#555}.layout-columns{display:grid;grid-template-columns:2fr 1fr;gap:2rem;margin-top:2rem}.main-column{min-width:0}.side-column{min-width:0}@media (max-width:768px){.layout-columns{grid-template-columns:1fr}}.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:1.5rem;margin-top:1.5rem}.video-card{background:var(--bg-light);border-radius:8px;overflow:hidden;box-shadow:var(--shadow-light);transition:all .3s ease;display:flex;flex-direction:column}.video-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-hover)}.video-card-title{font-size:1.1rem;font-weight:600;color:var(--text-dark);padding:1rem;line-height:1.4}.video-card-meta{padding:0 1rem;font-size:.9rem;color:#666;display:flex;flex-wrap:wrap;gap:.5rem}.video-card-meta span{background:#f0f2f5;padding:.2rem .6rem;border-radius:4px;font-size:.85rem}.video-card-desc{padding:1rem;font-size:.95rem;color:#555;line-height:1.6;flex:1}.video-card-link{padding:1rem;background:var(--primary-color);color:var(--text-light);text-align:center;font-weight:600;transition:background .3s ease}.video-card-link:hover{background:#234a85;color:var(--text-light)}.detail-header{background:var(--bg-dark);color:var(--text-light);padding:2rem;border-radius:12px 12px 0 0;margin:-2rem -2rem 2rem -2rem}.detail-meta{display:flex;flex-wrap:wrap;gap:1rem;margin-top:1rem;font-size:.95rem}.detail-meta-item{background:rgba(255,255,255,.1);padding:.5rem 1rem;border-radius:6px}.detail-content{line-height:1.8;color:#444;margin:1.5rem 0}.detail-content p{margin-bottom:1rem}.tags{display:flex;flex-wrap:wrap;gap:.5rem;margin:1rem 0}.tag{background:#e8f4fd;color:var(--primary-color);padding:.4rem 1rem;border-radius:20px;font-size:.9rem}.related-videos{margin-top:3rem}.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:1rem;margin-top:1rem}.related-card{background:#f8f9fa;padding:1rem;border-radius:8px;border-left:3px solid var(--primary-color);transition:all .3s ease}.related-card:hover{background:#fff;box-shadow:var(--shadow-light);transform:translateX(4px)}.related-card-title{font-weight:600;color:var(--text-dark);margin-bottom:.5rem}.related-card-desc{font-size:.9rem;color:#666;line-height:1.5}.list-intro{background:#fffbf0;border-left:4px solid var(--secondary-color);padding:1.5rem;margin-bottom:2rem;border-radius:6px}.list-intro p{margin-bottom:.8rem;line-height:1.6}.list-intro a{color:var(--secondary-color);font-weight:600;margin:0 .3rem}.list-item{background:var(--bg-light);padding:1.5rem;margin-bottom:1rem;border-radius:8px;border-left:4px solid var(--primary-color);transition:all .3s ease}.list-item:hover{box-shadow:var(--shadow-hover);transform:translateX(4px)}.list-item-title{font-size:1.3rem;font-weight:600;color:var(--text-dark);margin-bottom:.8rem}.list-item-title a{color:var(--text-dark)}.list-item-title a:hover{color:var(--primary-color)}.list-item-meta{display:flex;flex-wrap:wrap;gap:1rem;font-size:.9rem;color:#666;margin-bottom:1rem}.list-item-desc{color:#555;line-height:1.7}.error-page{text-align:center;padding:4rem 2rem}.error-page h1{font-size:4rem;color:var(--primary-color);margin-bottom:1rem}.error-page p{font-size:1.2rem;color:#666;margin-bottom:2rem}.error-page a{display:inline-block;background:var(--primary-color);color:var(--text-light);padding:.8rem 2rem;border-radius:6px;font-weight:600;transition:all .3s ease}.error-page a:hover{background:#234a85;transform:translateY(-2px);box-shadow:var(--shadow-hover)}@media (max-width:768px){main{padding:0 .5rem;margin:1rem auto}section{padding:1.5rem;margin-bottom:1.5rem}h1{font-size:1.5rem}h2{font-size:1.3rem}.video-grid{grid-template-columns:1fr;gap:1rem}.related-grid{grid-template-columns:1fr}.detail-header{padding:1.5rem;margin:-1.5rem -1.5rem 1.5rem -1.5rem}}.back-to-top{position:fixed;bottom:2rem;right:2rem;background:var(--primary-color);color:var(--text-light);width:48px;height:48px;border-radius:50%;display:flex;align-items:center;justify-content:center;cursor:pointer;opacity:0;visibility:hidden;transition:all .3s ease;box-shadow:var(--shadow-hover);z-index:999}.back-to-top.visible{opacity:1;visibility:visible}.back-to-top:hover{background:#234a85;transform:translateY(-4px)}