*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#2ecc71;
  --primary-dark:#27ae60;
  --accent:#e74c3c;
  --text:#333;
  --text-light:#666;
  --bg:#f8f9fa;
  --white:#fff;
  --shadow:0 2px 12px rgba(0,0,0,.08);
  --shadow-hover:0 6px 24px rgba(0,0,0,.12);
  --radius:12px;
  --transition:all .3s ease;
  --max-width:1200px;
  --header-h:68px;
}
html{font-size:16px;scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:var(--text);background:var(--bg);line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:var(--primary-dark);text-decoration:none;transition:var(--transition)}
a:hover{color:var(--accent)}
img{max-width:100%;height:auto;display:block}
ul,ol{list-style:none}
.container{width:100%;max-width:var(--max-width);margin:0 auto;padding:0 20px}

.site-header{position:sticky;top:0;z-index:1000;background:var(--white);box-shadow:var(--shadow);height:var(--header-h)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:var(--header-h)}
.logo-wrap h1{margin:0;line-height:1}
.logo-wrap img{height:44px;width:auto}
.main-nav{display:flex;align-items:center;gap:6px}
.main-nav a{padding:8px 16px;border-radius:8px;font-size:.95rem;font-weight:500;color:var(--text);transition:var(--transition)}
.main-nav a:hover,.main-nav a.active{background:var(--primary);color:var(--white)}
.search-box{position:relative;margin-left:12px}
.search-box input{width:200px;padding:8px 36px 8px 14px;border:2px solid #e0e0e0;border-radius:24px;font-size:.9rem;outline:none;transition:var(--transition)}
.search-box input:focus{border-color:var(--primary);width:260px}
.search-box button{position:absolute;right:4px;top:50%;transform:translateY(-50%);background:var(--primary);border:none;color:var(--white);width:30px;height:30px;border-radius:50%;cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center}
.hamburger{display:none;flex-direction:column;gap:5px;cursor:pointer;padding:8px;background:none;border:none}
.hamburger span{display:block;width:24px;height:2px;background:var(--text);transition:var(--transition)}

.breadcrumb{padding:16px 0;font-size:.88rem;color:var(--text-light)}
.breadcrumb a{color:var(--primary-dark)}
.breadcrumb span{margin:0 6px;color:#ccc}

.hero{background:linear-gradient(135deg,#1a1a2e 0%,#16213e 50%,#0f3460 100%);color:var(--white);padding:60px 0;text-align:center;position:relative;overflow:hidden}
.hero::before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle,rgba(46,204,113,.15) 0%,transparent 60%);animation:heroGlow 8s ease-in-out infinite alternate}
@keyframes heroGlow{0%{transform:translate(0,0)}100%{transform:translate(5%,5%)}}
.hero h2{font-size:2.2rem;margin-bottom:16px;position:relative}
.hero p{font-size:1.1rem;opacity:.9;max-width:640px;margin:0 auto;position:relative}

.section{padding:50px 0}
.section-title{text-align:center;margin-bottom:36px}
.section-title h2{font-size:1.8rem;color:var(--text);position:relative;display:inline-block;padding-bottom:12px}
.section-title h2::after{content:"";position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:60px;height:3px;background:var(--primary);border-radius:2px}
.section-title p{color:var(--text-light);margin-top:10px;font-size:.95rem}

.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:24px}
.video-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:var(--transition);position:relative}
.video-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-hover)}
.video-thumb{position:relative;padding-top:56.25%;overflow:hidden;background:#1a1a2e}
.video-thumb img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;transition:var(--transition)}
.video-card:hover .video-thumb img{transform:scale(1.05);filter:brightness(.7)}
.play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%) scale(0);width:56px;height:56px;background:rgba(46,204,113,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;transition:var(--transition);z-index:2}
.play-btn::after{content:"";display:block;width:0;height:0;border-style:solid;border-width:10px 0 10px 18px;border-color:transparent transparent transparent var(--white);margin-left:3px}
.video-card:hover .play-btn{transform:translate(-50%,-50%) scale(1)}
.video-overlay{position:absolute;inset:0;background:linear-gradient(180deg,transparent 40%,rgba(0,0,0,.6) 100%);opacity:0;transition:var(--transition)}
.video-card:hover .video-overlay{opacity:1}
.video-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.8);color:var(--white);padding:2px 8px;border-radius:4px;font-size:.78rem;z-index:3}
.video-info{padding:14px 16px}
.video-info h3{font-size:1rem;margin-bottom:6px;line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.video-info p{font-size:.85rem;color:var(--text-light);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.video-meta{display:flex;align-items:center;justify-content:space-between;padding:0 16px 12px;font-size:.8rem;color:#999}

.ai-section{background:linear-gradient(135deg,#0f3460,#1a1a2e);color:var(--white);padding:60px 0}
.ai-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px}
.ai-card{background:rgba(255,255,255,.08);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.12);border-radius:var(--radius);padding:28px;transition:var(--transition)}
.ai-card:hover{background:rgba(255,255,255,.14);transform:translateY(-4px)}
.ai-card .icon{font-size:2.4rem;margin-bottom:14px}
.ai-card h3{font-size:1.15rem;margin-bottom:10px}
.ai-card p{font-size:.92rem;opacity:.85;line-height:1.7}

.reviews{background:var(--white)}
.review-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}
.review-card{background:var(--bg);border-radius:var(--radius);padding:24px;position:relative;transition:var(--transition)}
.review-card:hover{box-shadow:var(--shadow-hover)}
.review-card::before{content:"\201C";position:absolute;top:10px;left:16px;font-size:3rem;color:var(--primary);opacity:.3;font-family:serif;line-height:1}
.review-card .stars{color:#f39c12;font-size:.9rem;margin-bottom:10px;letter-spacing:2px}
.review-card .text{font-size:.92rem;color:var(--text);line-height:1.7;margin-bottom:12px;padding-top:8px}
.review-card .author{font-size:.85rem;color:var(--text-light);font-weight:600}

.experts-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:28px}
.expert-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);text-align:center;padding:32px 24px;transition:var(--transition)}
.expert-card:hover{box-shadow:var(--shadow-hover);transform:translateY(-4px)}
.expert-card img{width:120px;height:120px;border-radius:50%;object-fit:cover;margin:0 auto 16px;border:4px solid var(--primary)}
.expert-card h3{font-size:1.1rem;margin-bottom:6px}
.expert-card .title{color:var(--primary-dark);font-size:.88rem;margin-bottom:12px}
.expert-card p{font-size:.9rem;color:var(--text-light);line-height:1.6;margin-bottom:16px}
.btn{display:inline-block;padding:10px 24px;border-radius:8px;font-size:.92rem;font-weight:500;cursor:pointer;transition:var(--transition);border:none}
.btn-primary{background:var(--primary);color:var(--white)}
.btn-primary:hover{background:var(--primary-dark);color:var(--white)}
.btn-outline{border:2px solid var(--primary);color:var(--primary);background:transparent}
.btn-outline:hover{background:var(--primary);color:var(--white)}

.faq-section{background:var(--bg)}
.faq-list{max-width:800px;margin:0 auto}
.faq-list details{background:var(--white);border-radius:var(--radius);margin-bottom:12px;box-shadow:var(--shadow);overflow:hidden}
.faq-list summary{padding:18px 24px;font-size:1rem;font-weight:600;cursor:pointer;position:relative;padding-right:48px;list-style:none}
.faq-list summary::-webkit-details-marker{display:none}
.faq-list summary::after{content:"+";position:absolute;right:24px;top:50%;transform:translateY(-50%);font-size:1.4rem;color:var(--primary);transition:var(--transition)}
.faq-list details[open] summary::after{content:"-"}
.faq-list .faq-answer{padding:0 24px 18px;font-size:.92rem;color:var(--text-light);line-height:1.8}

.site-footer{background:#1a1a2e;color:rgba(255,255,255,.7);padding:40px 0 20px}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:32px;margin-bottom:32px}
.footer-col h4{color:var(--white);font-size:1rem;margin-bottom:14px;position:relative;padding-bottom:8px}
.footer-col h4::after{content:"";position:absolute;bottom:0;left:0;width:32px;height:2px;background:var(--primary)}
.footer-col a{display:block;color:rgba(255,255,255,.6);padding:4px 0;font-size:.9rem;transition:var(--transition)}
.footer-col a:hover{color:var(--primary);padding-left:4px}
.footer-col p{font-size:.88rem;line-height:1.7}
.share-icons{display:flex;gap:12px;margin-top:12px}
.share-icons a{display:flex;align-items:center;justify-content:center;width:38px;height:38px;border-radius:50%;background:rgba(255,255,255,.1);color:var(--white);font-size:1.1rem;transition:var(--transition)}
.share-icons a:hover{background:var(--primary);transform:translateY(-2px)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:20px;text-align:center;font-size:.84rem}
.footer-bottom p{margin:4px 0}

.page-hero{background:linear-gradient(135deg,#1a1a2e,#0f3460);color:var(--white);padding:48px 0;text-align:center}
.page-hero h2{font-size:2rem;margin-bottom:10px}
.page-hero p{opacity:.85;font-size:1rem}
.content-section{background:var(--white);padding:48px 0}
.content-section .content-wrap{max-width:800px;margin:0 auto}
.content-section h3{font-size:1.3rem;margin:28px 0 14px;color:var(--text);border-left:4px solid var(--primary);padding-left:14px}
.content-section p{margin-bottom:16px;line-height:1.8;color:var(--text-light)}

@media(max-width:768px){
  .header-inner{flex-wrap:wrap}
  .main-nav{display:none;width:100%;flex-direction:column;padding:12px 0;gap:2px}
  .main-nav.open{display:flex}
  .main-nav a{width:100%;text-align:center;padding:12px}
  .search-box{width:100%;margin:10px 0 0}
  .search-box input{width:100%}
  .search-box input:focus{width:100%}
  .hamburger{display:flex}
  .hero h2{font-size:1.6rem}
  .hero p{font-size:.95rem}
  .video-grid{grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px}
  .section{padding:36px 0}
  .section-title h2{font-size:1.4rem}
  .ai-grid{grid-template-columns:1fr}
  .review-grid{grid-template-columns:1fr}
  .experts-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
}
@media(max-width:480px){
  .video-grid{grid-template-columns:1fr}
  .container{padding:0 14px}
  .hero{padding:40px 0}
  .hero h2{font-size:1.35rem}
}