:root{--blue-primary:#0047AB;--blue-dark:#003380;--blue-light:#E6F0FF;--red-accent:#D81E05;--red-light:#FFE8E8;--bg-base:#FAFBFF;--text-dark:#1A1A2E;--card-bg:rgba(0,40,120,0.06);--card-hover-border:linear-gradient(135deg,#0047AB,#D81E05);--nav-height:72px}*{margin:0;padding:0;box-sizing:border-box}html{scroll-behavior:smooth}body{font-family:'PingFang SC','Microsoft YaHei',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;background-color:var(--bg-base);color:var(--text-dark);line-height:1.7;overflow-x:hidden}body::before{content:'';position:fixed;top:0;left:0;right:0;bottom:0;background-image:linear-gradient(30deg,rgba(0,71,171,0.03) 12%,transparent 12.5%,transparent 87%,rgba(0,71,171,0.03) 87.5%),linear-gradient(150deg,rgba(216,30,5,0.02) 12%,transparent 12.5%,transparent 87%,rgba(216,30,5,0.02) 87.5%),linear-gradient(60deg,rgba(0,71,171,0.02) 25%,transparent 25.5%,transparent 75%,rgba(0,71,171,0.02) 75%);background-size:80px 140px;pointer-events:none;z-index:0}.main-nav{position:fixed;top:0;left:0;right:0;z-index:1000;padding:18px 0;transition:all .4s;background:rgba(255,255,255,.85);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border-bottom:1px solid rgba(0,71,171,.08)}.main-nav.scrolled{background:rgba(255,255,255,.95);box-shadow:0 4px 30px rgba(0,71,171,.1);padding:10px 0}.nav-inner{max-width:1200px;margin:0 auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between}.nav-logo{display:flex;align-items:center;gap:12px}.nav-logo-img{width:65px;height:auto;object-fit:contain;border-radius:8px;box-shadow:0 0 15px rgba(0,71,171,.2);transition:all .3s ease}.nav-logo:hover .nav-logo-img{box-shadow:0 0 25px rgba(0,71,171,.4);transform:scale(1.05)}.nav-logo-icon{width:44px;height:44px;background:linear-gradient(135deg,var(--blue-primary),var(--red-accent));border-radius:12px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:900;font-size:20px;box-shadow:0 0 20px rgba(0,71,171,0.3);animation:logoPulse 3s ease-in-out infinite}@keyframes logoPulse{0%,100%{box-shadow:0 0 20px rgba(0,71,171,0.3)}50%{box-shadow:0 0 30px rgba(0,71,171,0.5)}}.nav-logo-text{font-weight:700;font-size:16px;color:var(--blue-primary)}.nav-links{display:flex;align-items:center;gap:8px;list-style:none}.nav-links a{padding:8px 16px;font-size:14.5px;font-weight:500;color:var(--text-dark);border-radius:8px;transition:all .3s;position:relative}.nav-links a:hover{color:var(--blue-primary);background:var(--blue-light)}.nav-links a.active{color:var(--blue-primary);background:var(--blue-light)}.nav-links .nav-cta{background:linear-gradient(135deg,var(--blue-primary),var(--red-accent));color:#fff!important;padding:10px 24px;border-radius:24px;font-weight:600;box-shadow:0 4px 15px rgba(216,30,5,0.25);animation:ctaGlow 2.5s ease-in-out infinite}.nav-links .nav-cta:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(216,30,5,0.35)}@keyframes ctaGlow{0%,100%{box-shadow:0 4px 15px rgba(216,30,5,0.25)}50%{box-shadow:0 4px 25px rgba(216,30,5,0.4)}}.nav-toggle{flex-direction:column;gap:5px;cursor:pointer;padding:8px}.nav-toggle span{width:24px;height:2.5px;background:var(--blue-primary);border-radius:2px;transition:all .3s}.subpage-header{padding:140px 24px 80px;background:linear-gradient(135deg,var(--blue-primary) 0%,#003380 50%,#1a0a30 100%);position:relative;overflow:hidden;text-align:center;color:#fff}.subpage-header::before{content:'';position:absolute;top:-50%;right:-30%;width:600px;height:600px;background:radial-gradient(circle,rgba(216,30,5,0.15),transparent 70%);border-radius:50%}.subpage-header::after{content:'';position:absolute;bottom:-30%;left:-20%;width:400px;height:400px;background:radial-gradient(circle,rgba(0,71,171,0.2),transparent 70%);border-radius:50%}.subpage-title{font-size:clamp(28px,4vw,44px);font-weight:800;margin-bottom:12px;position:relative;z-index:1}.subpage-breadcrumb{font-size:14px;opacity:.8;position:relative;z-index:1}.subpage-breadcrumb a{color:#fff;text-decoration:none;opacity:.8;transition:opacity .3s ease}.subpage-breadcrumb a:hover{opacity:1}.video-gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin-top:40px}.video-card{cursor:pointer;transition:all .4s ease;overflow:hidden;padding:0!important}.video-card:hover{transform:translateY(-8px);box-shadow:0 20px 50px rgba(0,71,171,0.15),0 0 0 2px rgba(0,71,171,0.1)}.video-thumbnail{position:relative;width:100%;height:200px;overflow:hidden}.video-thumbnail canvas{width:100%;height:100%;object-fit:cover;transition:transform .5s ease;display:block;background:#e6f0ff}.video-thumbnail img{width:100%;height:100%;object-fit:cover;transition:transform .5s ease}.video-card:hover .video-thumbnail img{transform:scale(1.05)}.video-play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:64px;height:64px;background:rgba(0,71,171,0.7);border-radius:50%;display:flex;align-items:center;justify-content:center;transition:all .3s ease;backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}.video-card:hover .video-play-btn{background:rgba(216,30,5,0.8);transform:translate(-50%,-50%) scale(1.1);box-shadow:0 0 30px rgba(216,30,5,0.4)}.video-play-btn svg{margin-left:4px}.video-title{padding:16px 20px;font-size:15px;font-weight:600;color:var(--text-dark);text-align:center;background:rgba(255,255,255,0.5)}.video-modal{display:none;position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,0.9);z-index:10000;align-items:center;justify-content:center;padding:20px;backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}.video-modal.active{display:flex}.video-modal-content{position:relative;max-width:900px;width:100%;background:rgba(255,255,255,0.95);border-radius:16px;overflow:hidden;box-shadow:0 30px 80px rgba(0,0,0,0.5)}.video-modal-close{position:absolute;top:16px;right:16px;width:40px;height:40px;background:rgba(0,0,0,0.6);border:none;border-radius:50%;color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .3s ease;z-index:10}.video-modal-close:hover{background:var(--red-accent);transform:rotate(90deg)}.video-player-wrapper{width:100%;aspect-ratio:16/9;background:linear-gradient(160deg,#0047AB,#003380,#1a0a30)}.video-player-wrapper video{width:100%;height:100%;object-fit:contain}.video-modal-title{padding:20px 24px;font-size:18px;font-weight:600;color:var(--text-dark);text-align:center;background:#fff}.image-lightbox{display:none;position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,0.92);z-index:9999;align-items:center;justify-content:center;padding:20px;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);cursor:zoom-out;touch-action:none}.image-lightbox.active{display:flex}.image-lightbox-content{position:relative;max-width:90vw;max-height:90vh;cursor:default;user-select:none;-webkit-user-select:none}.image-lightbox-content img{max-width:90vw;max-height:85vh;object-fit:contain;border-radius:8px;box-shadow:0 20px 60px rgba(0,0,0,0.5);display:block;user-select:none;-webkit-user-drag:none}.image-lightbox-caption{position:absolute;bottom:-40px;left:50%;transform:translateX(-50%);color:#fff;font-size:15px;font-weight:500;text-align:center;white-space:nowrap;text-shadow:0 2px 8px rgba(0,0,0,0.5)}.image-lightbox-close{position:fixed;top:20px;right:20px;width:44px;height:44px;background:rgba(255,255,255,0.15);border:none;border-radius:50%;color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .3s ease;z-index:10000;backdrop-filter:blur(10px);-webkit-tap-highlight-color:transparent}.image-lightbox-close:hover{background:var(--red-accent);transform:rotate(90deg) scale(1.1)}.image-lightbox-loader{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);color:#fff;font-size:14px;opacity:0.7}.image-lightbox-error{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);color:#fff;font-size:16px;text-align:center;opacity:0.6}.gallery-photo{cursor:zoom-in;transition:all .4s ease}.gallery-photo:hover{transform:translateY(-6px);box-shadow:0 16px 40px rgba(0,71,171,0.18),0 0 0 2px rgba(0,71,171,0.12)}.gallery-photo img{transition:transform .4s ease}.gallery-photo:hover img{transform:scale(1.03)}@media(max-width:1024px){.video-gallery{grid-template-columns:repeat(2,1fr)}}@media(max-width:640px){.video-gallery{grid-template-columns:1fr}.image-lightbox-close{width:52px;height:52px;top:16px;right:16px}.image-lightbox-close svg{width:28px;height:28px}.image-lightbox-content img{max-width:95vw;max-height:80vh}.image-lightbox-caption{font-size:13px;bottom:-32px}}
/* PC端性能优化：简化高精度滤镜和复杂渐变 */
@media (min-width: 1025px) and (hover: hover) {
  /* 简化背景渐变层数 */
  body::before {
    background-image: linear-gradient(30deg, rgba(0,71,171,0.03) 12%, transparent 12.5%, transparent 87%, rgba(0,71,171,0.03) 87.5%) !important;
    background-size: 80px 140px !important;
  }
  
  /* 减少backdrop-filter模糊度 */
  .main-nav {
    backdrop-filter: blur(12px) !important;
    -webkit-backdrop-filter: blur(12px) !important;
  }
  
  /* 简化卡片悬浮效果 */
  .course-card, .photo-card, .video-card {
    transition: transform 0.2s ease, box-shadow 0.2s ease !important;
  }
  
  /* 简化视频卡片光晕效果 */
  .video-card::before {
    animation-duration: 10s !important;
  }
  
  /* 减少视频弹窗模糊度 */
  .video-modal-backdrop {
    backdrop-filter: blur(10px) !important;
    -webkit-backdrop-filter: blur(10px) !important;
  }
  
  /* 简化筛选按钮悬浮效果 */
  .filter-btn {
    transition: all 0.2s ease !important;
  }
}