/* ========================================
   四虎视频 视频社区 - 主样式表
   原创设计 hfspnj.cn
   ======================================== */

/* CSS Reset & Base */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;color:#333;background:#F8F9FA;line-height:1.7;overflow-x:hidden}
a{color:#1A6B3C;text-decoration:none;transition:color .3s}
a:hover{color:#F5A623}
img{max-width:100%;height:auto;display:block}
ul,ol{list-style:none}
h1,h2,h3,h4,h5,h6{font-weight:700;line-height:1.3;color:#1C2331}

/* Container */
.container{max-width:1200px;margin:0 auto;padding:0 20px}

/* ===== Header & Navigation ===== */
.site-header{background:#1C2331;position:sticky;top:0;z-index:1000;box-shadow:0 2px 12px rgba(0,0,0,.15)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:10px 20px;max-width:1200px;margin:0 auto}
.site-logo{display:flex;align-items:center;gap:10px}
.site-logo img{width:48px;height:48px;border-radius:8px}
.site-logo span{font-size:1.5rem;font-weight:800;color:#F5A623;letter-spacing:1px}
.main-nav{display:flex;align-items:center;gap:0}
.main-nav a{color:#fff;padding:12px 16px;font-size:.95rem;transition:all .3s;border-bottom:3px solid transparent}
.main-nav a:hover,.main-nav a.active{color:#F5A623;border-bottom-color:#F5A623;background:rgba(245,166,35,.08)}
.nav-toggle{display:none;background:none;border:none;color:#fff;font-size:1.5rem;cursor:pointer;padding:8px}

/* Search Bar */
.search-bar{background:linear-gradient(135deg,#1A6B3C 0%,#2D9CDB 100%);padding:16px 0}
.search-bar .container{display:flex;justify-content:center}
.search-form{display:flex;max-width:600px;width:100%;background:#fff;border-radius:50px;overflow:hidden;box-shadow:0 4px 15px rgba(0,0,0,.1)}
.search-form input{flex:1;border:none;padding:12px 24px;font-size:1rem;outline:none;background:transparent}
.search-form button{background:#F5A623;color:#fff;border:none;padding:12px 28px;font-size:1rem;cursor:pointer;transition:background .3s;font-weight:600}
.search-form button:hover{background:#e6951a}

/* ===== Banner ===== */
.hero-banner{position:relative;overflow:hidden;min-height:480px;display:flex;align-items:center;justify-content:center}
.hero-banner .banner-bg{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;z-index:0}
.hero-banner .banner-overlay{position:absolute;top:0;left:0;width:100%;height:100%;background:linear-gradient(135deg,rgba(26,107,60,.85) 0%,rgba(28,35,49,.75) 100%);z-index:1}
.hero-content{position:relative;z-index:2;text-align:center;color:#fff;padding:60px 20px}
.hero-content h1{font-size:2.8rem;margin-bottom:16px;text-shadow:2px 2px 8px rgba(0,0,0,.3)}
.hero-content h1 em{font-style:normal;color:#F5A623}
.hero-content p{font-size:1.2rem;max-width:700px;margin:0 auto 24px;opacity:.95;line-height:1.8}
.hero-content .hero-tags{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin-top:20px}
.hero-content .hero-tags span{background:rgba(255,255,255,.18);padding:6px 18px;border-radius:20px;font-size:.9rem;backdrop-filter:blur(4px)}

/* ===== Section Common ===== */
.section{padding:60px 0}
.section-alt{background:#fff}
.section-dark{background:#1C2331;color:#fff}
.section-dark h2,.section-dark h3,.section-dark h4{color:#fff}
.section-title{text-align:center;margin-bottom:40px}
.section-title h2{font-size:2rem;margin-bottom:10px;position:relative;display:inline-block}
.section-title h2::after{content:'';display:block;width:60px;height:4px;background:linear-gradient(90deg,#1A6B3C,#F5A623);margin:12px auto 0;border-radius:2px}
.section-title p{color:#666;font-size:1.05rem;margin-top:8px}
.section-dark .section-title p{color:rgba(255,255,255,.7)}

/* ===== Video Card Grid ===== */
.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:24px}
.video-card{background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 4px 16px rgba(0,0,0,.08);transition:transform .3s,box-shadow .3s;cursor:pointer}
.video-card:hover{transform:translateY(-6px);box-shadow:0 8px 30px rgba(0,0,0,.15)}
.video-thumb{position:relative;padding-top:56.25%;overflow:hidden;background:#e0e0e0}
.video-thumb img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;transition:transform .4s}
.video-card:hover .video-thumb img{transform:scale(1.08)}
.video-play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:60px;height:60px;background:rgba(245,166,35,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s;z-index:2}
.video-play-btn::after{content:'';border-style:solid;border-width:10px 0 10px 18px;border-color:transparent transparent transparent #fff;margin-left:3px}
.video-card:hover .video-play-btn{opacity:1}
.video-info{padding:16px}
.video-info h3{font-size:1.05rem;margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.video-meta{display:flex;gap:16px;color:#999;font-size:.85rem}
.video-meta span{display:flex;align-items:center;gap:4px}
.video-tag{display:inline-block;background:#E8F5E9;color:#1A6B3C;padding:2px 10px;border-radius:12px;font-size:.78rem;margin-top:8px}

/* Duration Badge */
.video-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.75);color:#fff;padding:2px 8px;border-radius:4px;font-size:.78rem;z-index:2}

/* ===== Expert Cards ===== */
.expert-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:24px}
.expert-card{background:#fff;border-radius:12px;padding:30px 20px;text-align:center;box-shadow:0 4px 16px rgba(0,0,0,.08);transition:transform .3s}
.expert-card:hover{transform:translateY(-4px)}
.expert-card img{width:120px;height:120px;border-radius:50%;margin:0 auto 16px;object-fit:cover;border:4px solid #E8F5E9}
.expert-card h4{font-size:1.1rem;margin-bottom:6px}
.expert-card .expert-role{color:#1A6B3C;font-size:.9rem;margin-bottom:10px}
.expert-card p{font-size:.88rem;color:#666;line-height:1.6;margin-bottom:14px}
.expert-card .expert-btns{display:flex;gap:10px;justify-content:center}
.btn{display:inline-block;padding:8px 20px;border-radius:25px;font-size:.88rem;font-weight:600;transition:all .3s;cursor:pointer;border:none}
.btn-primary{background:#1A6B3C;color:#fff}
.btn-primary:hover{background:#15572f;color:#fff}
.btn-outline{background:transparent;color:#1A6B3C;border:2px solid #1A6B3C}
.btn-outline:hover{background:#1A6B3C;color:#fff}
.btn-orange{background:#F5A623;color:#fff}
.btn-orange:hover{background:#e6951a;color:#fff}

/* ===== Community Section ===== */
.community-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:20px}
.community-item{background:linear-gradient(135deg,#E8F5E9,#E3F2FD);border-radius:12px;padding:24px;text-align:center;transition:transform .3s,box-shadow .3s}
.community-item:hover{transform:translateY(-4px);box-shadow:0 6px 20px rgba(0,0,0,.1)}
.community-item .comm-icon{font-size:2.5rem;margin-bottom:12px}
.community-item h4{font-size:1rem;margin-bottom:6px}
.community-item p{font-size:.85rem;color:#666}

/* ===== AI Section ===== */
.ai-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.ai-card{background:linear-gradient(135deg,#1C2331,#2D4059);border-radius:16px;padding:30px;color:#fff;transition:transform .3s}
.ai-card:hover{transform:translateY(-4px)}
.ai-card h4{font-size:1.15rem;margin-bottom:10px;color:#F5A623}
.ai-card p{font-size:.92rem;opacity:.85;line-height:1.7}
.ai-card img{border-radius:10px;margin-bottom:16px}

/* ===== Reviews ===== */
.review-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}
.review-card{background:#fff;border-radius:12px;padding:24px;box-shadow:0 2px 12px rgba(0,0,0,.06);border-left:4px solid #1A6B3C}
.review-card .review-stars{color:#F5A623;font-size:1.1rem;margin-bottom:8px}
.review-card p{font-size:.95rem;color:#555;line-height:1.7;margin-bottom:12px;font-style:italic}
.review-card .reviewer{font-weight:600;color:#1C2331;font-size:.9rem}
.review-card .review-date{color:#999;font-size:.82rem}

/* ===== FAQ ===== */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:#fff;border-radius:10px;margin-bottom:12px;overflow:hidden;box-shadow:0 2px 8px rgba(0,0,0,.05)}
.faq-question{padding:18px 24px;cursor:pointer;font-weight:600;font-size:1rem;display:flex;justify-content:space-between;align-items:center;transition:background .3s}
.faq-question:hover{background:#f0f7f1}
.faq-question::after{content:'+';font-size:1.4rem;color:#1A6B3C;transition:transform .3s}
.faq-item.active .faq-question::after{transform:rotate(45deg)}
.faq-answer{padding:0 24px;max-height:0;overflow:hidden;transition:max-height .4s ease,padding .4s ease}
.faq-item.active .faq-answer{max-height:300px;padding:0 24px 18px}
.faq-answer p{color:#666;font-size:.95rem;line-height:1.8}

/* ===== Contact ===== */
.contact-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:24px}
.contact-card{background:#fff;border-radius:12px;padding:24px;text-align:center;box-shadow:0 2px 12px rgba(0,0,0,.06)}
.contact-card h4{margin-bottom:10px;color:#1A6B3C}
.contact-card p{font-size:.92rem;color:#666;line-height:1.7}
.contact-card img{max-width:160px;margin:12px auto}

/* ===== How-To Guide ===== */
.howto-steps{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:20px;margin-top:24px}
.howto-step{background:#fff;border-radius:12px;padding:24px;text-align:center;box-shadow:0 2px 10px rgba(0,0,0,.06);position:relative}
.howto-step .step-num{display:inline-flex;width:40px;height:40px;background:#1A6B3C;color:#fff;border-radius:50%;align-items:center;justify-content:center;font-weight:700;font-size:1.1rem;margin-bottom:12px}
.howto-step h4{font-size:1rem;margin-bottom:8px}
.howto-step p{font-size:.88rem;color:#666}

/* ===== Share Buttons ===== */
.share-bar{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-top:20px}
.share-btn{display:inline-flex;align-items:center;gap:6px;padding:8px 18px;border-radius:25px;color:#fff;font-size:.88rem;transition:opacity .3s}
.share-btn:hover{opacity:.85;color:#fff}
.share-wechat{background:#07C160}
.share-weibo{background:#E6162D}
.share-douyin{background:#161823}
.share-bilibili{background:#00A1D6}

/* ===== Footer ===== */
.site-footer{background:#1C2331;color:rgba(255,255,255,.7);padding:40px 0 20px}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:30px;margin-bottom:30px}
.footer-col h4{color:#F5A623;font-size:1.05rem;margin-bottom:14px}
.footer-col p,.footer-col a{font-size:.9rem;color:rgba(255,255,255,.65);line-height:1.9}
.footer-col a:hover{color:#F5A623}
.footer-col img{max-width:140px;border-radius:8px;margin-top:8px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:20px;text-align:center;font-size:.85rem}
.footer-bottom .footer-logo{display:flex;align-items:center;justify-content:center;gap:8px;margin-bottom:10px}
.footer-bottom .footer-logo img{width:36px;height:36px;border-radius:6px}
.footer-bottom .footer-logo span{color:#F5A623;font-weight:700;font-size:1.1rem}

/* ===== Breadcrumb ===== */
.breadcrumb{padding:14px 0;font-size:.88rem;color:#999}
.breadcrumb a{color:#1A6B3C}
.breadcrumb span{margin:0 6px;color:#ccc}

/* ===== Inner Page ===== */
.page-hero{background:linear-gradient(135deg,#1A6B3C,#2D9CDB);color:#fff;padding:50px 0;text-align:center}
.page-hero h1{font-size:2.2rem;color:#fff;margin-bottom:10px}
.page-hero p{font-size:1.05rem;opacity:.9}
.content-area{padding:40px 0}
.content-area h2{font-size:1.6rem;margin-bottom:16px;color:#1A6B3C}
.content-area h3{font-size:1.3rem;margin:24px 0 12px;color:#1C2331}
.content-area p{margin-bottom:16px;line-height:1.9;color:#555}

/* ===== Responsive ===== */
@media(max-width:768px){
  .header-inner{flex-wrap:wrap}
  .main-nav{display:none;flex-direction:column;width:100%;background:#1C2331;position:absolute;top:100%;left:0;z-index:999}
  .main-nav.show{display:flex}
  .main-nav a{padding:14px 20px;border-bottom:1px solid rgba(255,255,255,.05)}
  .nav-toggle{display:block}
  .hero-content h1{font-size:1.8rem}
  .hero-content p{font-size:1rem}
  .video-grid{grid-template-columns:1fr}
  .ai-grid{grid-template-columns:1fr}
  .expert-grid{grid-template-columns:1fr}
  .section{padding:40px 0}
  .section-title h2{font-size:1.6rem}
  .footer-grid{grid-template-columns:1fr}
}
@media(max-width:480px){
  .hero-content h1{font-size:1.5rem}
  .search-form{flex-direction:column;border-radius:12px}
  .search-form button{border-radius:0 0 12px 12px}
  .community-grid{grid-template-columns:repeat(2,1fr)}
}

/* ===== Lazy Load Placeholder ===== */
img[loading="lazy"]{opacity:0;transition:opacity .5s}
img[loading="lazy"].loaded,img[loading="lazy"][src]{opacity:1}

/* ===== Interference Tags (hidden) ===== */
.u20f7a{position:absolute;width:0;height:0;overflow:hidden;opacity:0;pointer-events:none;z-index:-9999}

/* ===== MCP Frontend Placeholder ===== */
.mcp-widget{background:linear-gradient(135deg,#f0f7f1,#e3f2fd);border-radius:12px;padding:20px;margin-top:20px;text-align:center;border:2px dashed #1A6B3C}
.mcp-widget h4{color:#1A6B3C;margin-bottom:8px}
.mcp-widget p{font-size:.88rem;color:#666}

/* ===== Animation ===== */
@keyframes fadeInUp{from{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}
.fade-in{animation:fadeInUp .6s ease forwards}

/* ===== Video Tag Highlight ===== */
.tag-video{background:#FFF3E0;color:#E65100;padding:2px 10px;border-radius:12px;font-size:.78rem;font-weight:600}
.tag-hot{background:#FFEBEE;color:#C62828;padding:2px 10px;border-radius:12px;font-size:.78rem;font-weight:600}
.tag-new{background:#E8F5E9;color:#2E7D32;padding:2px 10px;border-radius:12px;font-size:.78rem;font-weight:600}

/* ===== H5 Video Preview (hidden by default) ===== */
.video-preview{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;z-index:1;opacity:0;pointer-events:none}

/* ===== Back to Top ===== */
.back-to-top{position:fixed;bottom:30px;right:30px;width:44px;height:44px;background:#1A6B3C;color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.2rem;cursor:pointer;opacity:0;visibility:hidden;transition:all .3s;z-index:999;box-shadow:0 2px 10px rgba(0,0,0,.2)}
.back-to-top.show{opacity:1;visibility:visible}
.back-to-top:hover{background:#F5A623;transform:translateY(-3px)}

/* ===== Footer H5/H6 ===== */
.footer-col h5{color:#F5A623;font-size:1.05rem;margin-bottom:14px;font-weight:700}
.footer-col h6{color:#F5A623;font-size:1rem;margin-bottom:14px;font-weight:700}