/* ============================================
   四虎视频社区 - 全站样式表
   品牌：四虎视频 | 域名：cficdiv.cn
   原创设计 - 赛车红+深蓝配色方案
   ============================================ */

/* 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","Hiragino Sans GB","Helvetica Neue",Arial,sans-serif;color:#2B2D42;background:#F1FAEE;line-height:1.7;overflow-x:hidden}
a{text-decoration:none;color:inherit;transition:color .3s}
a:hover{color:#E63946}
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}

/* ---- 颜色变量 ---- */
:root{
  --red:#E63946;
  --navy:#1D3557;
  --orange:#F4A261;
  --light:#F1FAEE;
  --dark:#0D1B2A;
  --text:#2B2D42;
  --grey:#8D99AE;
  --white:#FFFFFF;
  --shadow:0 4px 24px rgba(13,27,42,.12);
  --radius:12px;
}

/* ---- 容器 ---- */
.container{width:100%;max-width:1280px;margin:0 auto;padding:0 20px}
.section{padding:60px 0}
.section-title{text-align:center;margin-bottom:40px}
.section-title h2{font-size:2rem;color:var(--navy);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:4px;background:var(--red);border-radius:2px}
.section-title p{color:var(--grey);margin-top:10px;font-size:1rem}

/* ---- 头部导航 ---- */
.site-header{background:var(--dark);position:sticky;top:0;z-index:1000;box-shadow:0 2px 12px rgba(0,0,0,.3)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:10px 20px;max-width:1280px;margin:0 auto}
.logo{display:flex;align-items:center;gap:10px}
.logo img{height:48px;width:auto}
.logo span{font-size:1.4rem;font-weight:800;color:var(--white);letter-spacing:1px}
.main-nav{display:flex;align-items:center;gap:0}
.main-nav a{color:var(--white);padding:10px 16px;font-size:.95rem;font-weight:500;transition:all .3s;border-bottom:3px solid transparent}
.main-nav a:hover,.main-nav a.active{color:var(--red);border-bottom-color:var(--red)}
.mobile-toggle{display:none;background:none;border:none;color:var(--white);font-size:1.6rem;cursor:pointer}

/* ---- 搜索框 ---- */
.search-bar{background:var(--navy);padding:12px 0}
.search-bar .container{display:flex;justify-content:center}
.search-box{display:flex;width:100%;max-width:600px;border-radius:30px;overflow:hidden;box-shadow:var(--shadow)}
.search-box input{flex:1;padding:12px 24px;border:none;font-size:1rem;outline:none;background:var(--white);color:var(--text)}
.search-box button{padding:12px 28px;background:var(--red);color:var(--white);border:none;font-size:1rem;font-weight:600;cursor:pointer;transition:background .3s}
.search-box button:hover{background:#c62d38}

/* ---- Banner ---- */
.banner{position:relative;height:520px;overflow:hidden;display:flex;align-items:center;justify-content:center}
.banner-bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:brightness(.55)}
.banner-content{position:relative;z-index:2;text-align:center;color:var(--white);padding:0 20px}
.banner-content h1{font-size:2.8rem;margin-bottom:16px;text-shadow:0 2px 12px rgba(0,0,0,.5)}
.banner-content p{font-size:1.15rem;max-width:700px;margin:0 auto 24px;line-height:1.8;text-shadow:0 1px 6px rgba(0,0,0,.4)}
.banner-content .btn{display:inline-block;padding:14px 36px;background:var(--red);color:var(--white);border-radius:30px;font-size:1.05rem;font-weight:600;transition:all .3s;box-shadow:0 4px 16px rgba(230,57,70,.4)}
.banner-content .btn:hover{background:#c62d38;transform:translateY(-2px)}

/* ---- 视频卡片 ---- */
.video-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.video-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:transform .3s,box-shadow .3s}
.video-card:hover{transform:translateY(-6px);box-shadow:0 8px 32px rgba(13,27,42,.18)}
.video-thumb{position:relative;padding-top:56.25%;overflow:hidden;cursor:pointer}
.video-thumb img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;transition:transform .4s}
.video-card:hover .video-thumb img{transform:scale(1.06)}
.play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:60px;height:60px;background:rgba(230,57,70,.85);border-radius:50%;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s}
.play-btn::after{content:"";border-left:20px solid var(--white);border-top:12px solid transparent;border-bottom:12px solid transparent;margin-left:4px}
.video-card:hover .play-btn{opacity:1}
.video-info{padding:16px}
.video-info h3{font-size:1rem;color:var(--navy);margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.video-meta{display:flex;gap:12px;color:var(--grey);font-size:.82rem}
.video-meta span{display:flex;align-items:center;gap:4px}
.video-tag{display:inline-block;padding:2px 10px;background:rgba(230,57,70,.1);color:var(--red);border-radius:20px;font-size:.75rem;margin-top:8px}

/* ---- 短视频风格 ---- */
.short-video-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:16px}
.short-card{position:relative;border-radius:var(--radius);overflow:hidden;padding-top:160%;cursor:pointer}
.short-card img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;transition:transform .4s}
.short-card:hover img{transform:scale(1.06)}
.short-card .overlay{position:absolute;bottom:0;left:0;right:0;padding:16px;background:linear-gradient(transparent,rgba(0,0,0,.8));color:var(--white)}
.short-card .overlay h4{font-size:.9rem;margin-bottom:4px}
.short-card .overlay span{font-size:.75rem;opacity:.8}
.short-card .play-btn{width:48px;height:48px}

/* ---- AI赋能 ---- */
.ai-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.ai-card{background:var(--white);border-radius:var(--radius);padding:32px 24px;text-align:center;box-shadow:var(--shadow);transition:transform .3s}
.ai-card:hover{transform:translateY(-4px)}
.ai-icon{width:64px;height:64px;margin:0 auto 16px;background:linear-gradient(135deg,var(--red),var(--orange));border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:1.8rem;color:var(--white)}
.ai-card h3{font-size:1.1rem;color:var(--navy);margin-bottom:10px}
.ai-card p{color:var(--grey);font-size:.9rem;line-height:1.6}

/* ---- 社区模块 ---- */
.community-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.community-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:transform .3s}
.community-card:hover{transform:translateY(-4px)}
.community-card img{width:100%;height:200px;object-fit:cover}
.community-card .card-body{padding:20px}
.community-card h3{font-size:1.05rem;color:var(--navy);margin-bottom:8px}
.community-card p{color:var(--grey);font-size:.88rem;line-height:1.6}
.community-card .stats{display:flex;gap:16px;margin-top:12px;font-size:.8rem;color:var(--grey)}

/* ---- 专家展示 ---- */
.expert-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:28px}
.expert-card{background:var(--white);border-radius:var(--radius);overflow:hidden;text-align:center;box-shadow:var(--shadow);transition:transform .3s}
.expert-card:hover{transform:translateY(-4px)}
.expert-card img{width:100%;height:240px;object-fit:cover}
.expert-card .info{padding:20px}
.expert-card h3{font-size:1.05rem;color:var(--navy);margin-bottom:4px}
.expert-card .title{color:var(--red);font-size:.85rem;margin-bottom:8px}
.expert-card p{color:var(--grey);font-size:.85rem;line-height:1.5}
.expert-card .btns{display:flex;gap:8px;justify-content:center;margin-top:14px}
.expert-card .btns a{padding:6px 16px;border-radius:20px;font-size:.82rem;font-weight:500;transition:all .3s}
.btn-primary{background:var(--red);color:var(--white)!important}
.btn-primary:hover{background:#c62d38}
.btn-outline{border:1px solid var(--navy);color:var(--navy)!important}
.btn-outline:hover{background:var(--navy);color:var(--white)!important}

/* ---- 合作品牌 ---- */
.partner-wall{display:flex;flex-wrap:wrap;justify-content:center;gap:32px;align-items:center}
.partner-wall img{height:60px;opacity:.6;transition:opacity .3s;filter:grayscale(100%)}
.partner-wall img:hover{opacity:1;filter:none}

/* ---- FAQ ---- */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:var(--white);border-radius:var(--radius);margin-bottom:12px;box-shadow:0 2px 8px rgba(13,27,42,.06);overflow:hidden}
.faq-q{padding:18px 24px;font-weight:600;color:var(--navy);cursor:pointer;display:flex;justify-content:space-between;align-items:center;transition:background .3s}
.faq-q:hover{background:rgba(230,57,70,.04)}
.faq-q::after{content:"+";font-size:1.4rem;color:var(--red);transition:transform .3s}
.faq-item.open .faq-q::after{transform:rotate(45deg)}
.faq-a{padding:0 24px;max-height:0;overflow:hidden;transition:all .4s;color:var(--grey);font-size:.92rem;line-height:1.7}
.faq-item.open .faq-a{padding:0 24px 18px;max-height:300px}

/* ---- 用户评论 ---- */
.review-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.review-card{background:var(--white);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}
.review-card .stars{color:var(--orange);font-size:1rem;margin-bottom:10px}
.review-card p{color:var(--text);font-size:.9rem;line-height:1.6;margin-bottom:12px;font-style:italic}
.review-card .reviewer{display:flex;align-items:center;gap:10px}
.reviewer-avatar{width:40px;height:40px;border-radius:50%;background:var(--navy);color:var(--white);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.9rem}
.reviewer-name{font-weight:600;color:var(--navy);font-size:.88rem}
.reviewer-date{color:var(--grey);font-size:.78rem}

/* ---- 页脚 ---- */
.site-footer{background:var(--dark);color:rgba(255,255,255,.7);padding:48px 0 0}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;padding-bottom:40px;border-bottom:1px solid rgba(255,255,255,.1)}
.footer-brand img{height:40px;margin-bottom:12px}
.footer-brand p{font-size:.88rem;line-height:1.6}
.footer-col h4{color:var(--white);font-size:1rem;margin-bottom:16px;position:relative;padding-bottom:8px}
.footer-col h4::after{content:"";position:absolute;bottom:0;left:0;width:30px;height:2px;background:var(--red)}
.footer-col a{display:block;padding:4px 0;font-size:.88rem;transition:color .3s}
.footer-col a:hover{color:var(--red)}
.footer-qr{display:flex;gap:20px;margin-top:16px}
.footer-qr img{width:100px;height:100px;border-radius:8px}
.footer-qr .qr-label{font-size:.78rem;text-align:center;margin-top:4px}
.footer-bottom{padding:20px 0;text-align:center;font-size:.82rem}
.footer-bottom .update-time{margin-top:4px;color:rgba(255,255,255,.5)}

/* ---- 社交分享 ---- */
.share-bar{display:flex;gap:12px;justify-content:center;margin-top:20px}
.share-btn{display:inline-flex;align-items:center;gap:6px;padding:8px 18px;border-radius:20px;font-size:.85rem;font-weight:500;color:var(--white);transition:all .3s}
.share-btn:hover{transform:translateY(-2px);color:var(--white)}
.share-wechat{background:#07C160}
.share-weibo{background:#E6162D}
.share-douyin{background:#161823}
.share-bilibili{background:#00A1D6}

/* ---- 面包屑 ---- */
.breadcrumb{padding:12px 0;font-size:.85rem;color:var(--grey)}
.breadcrumb a{color:var(--navy)}
.breadcrumb span{margin:0 6px;color:var(--grey)}

/* ---- 内页通用 ---- */
.page-hero{background:var(--navy);padding:48px 0;text-align:center;color:var(--white)}
.page-hero h1{font-size:2.2rem;margin-bottom:10px}
.page-hero p{font-size:1rem;opacity:.8}
.content-section{padding:40px 0}

/* ---- How-To指南 ---- */
.howto-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.step-card{background:var(--white);border-radius:var(--radius);padding:28px 20px;text-align:center;box-shadow:var(--shadow);position:relative}
.step-num{width:48px;height:48px;background:var(--red);color:var(--white);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.2rem;font-weight:700;margin:0 auto 14px}
.step-card h3{font-size:1rem;color:var(--navy);margin-bottom:8px}
.step-card p{color:var(--grey);font-size:.88rem}

/* ---- MCP前端占位 ---- */
.mcp-widget{background:var(--navy);border-radius:var(--radius);padding:24px;margin-top:20px;color:rgba(255,255,255,.8);text-align:center;font-size:.9rem}
.mcp-widget code{background:rgba(255,255,255,.1);padding:2px 8px;border-radius:4px;font-size:.82rem}

/* ---- 响应式 ---- */
@media(max-width:1024px){
  .video-grid{grid-template-columns:repeat(3,1fr)}
  .short-video-grid{grid-template-columns:repeat(3,1fr)}
  .expert-grid{grid-template-columns:repeat(2,1fr)}
  .review-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:repeat(2,1fr)}
  .howto-steps{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:768px){
  .header-inner{flex-wrap:wrap}
  .main-nav{display:none;width:100%;flex-direction:column;padding:10px 0}
  .main-nav.show{display:flex}
  .mobile-toggle{display:block}
  .banner{height:400px}
  .banner-content h1{font-size:1.8rem}
  .video-grid{grid-template-columns:repeat(2,1fr)}
  .short-video-grid{grid-template-columns:repeat(2,1fr)}
  .ai-grid{grid-template-columns:1fr}
  .community-grid{grid-template-columns:1fr}
  .expert-grid{grid-template-columns:1fr}
  .review-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .howto-steps{grid-template-columns:1fr}
  .section{padding:40px 0}
  .section-title h2{font-size:1.5rem}
}
@media(max-width:480px){
  .video-grid{grid-template-columns:1fr}
  .short-video-grid{grid-template-columns:1fr}
  .banner{height:320px}
  .banner-content h1{font-size:1.4rem}
  .search-box{flex-direction:column;border-radius:12px}
  .search-box button{border-radius:0 0 12px 12px}
}

/* ---- 懒加载 ---- */
img[loading="lazy"]{opacity:0;transition:opacity .5s}
img[loading="lazy"].loaded,img[loading="lazy"][src]{opacity:1}

/* ---- 动画 ---- */
.fade-in{opacity:0;transform:translateY(20px);transition:all .6s ease-out}
.fade-in.visible{opacity:1;transform:translateY(0)}

/* ---- H5 Video 播放器 ---- */
.video-player{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:none;z-index:1}
.video-poster{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:2}
.play-btn{z-index:5}
.play-btn.playing::after{content:"";border-left:8px solid var(--white);border-right:8px solid var(--white);border-top:none;border-bottom:none;width:20px;height:20px;margin-left:0}
.video-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.75);color:var(--white);padding:2px 8px;border-radius:4px;font-size:.75rem;z-index:3}
.short-card .video-player{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:none;z-index:1}
.short-card .video-poster{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:2}
.short-card .play-btn{z-index:5}

/* ---- 面包屑导航条 ---- */
.breadcrumb-nav{background:var(--navy);padding:8px 0;border-bottom:1px solid rgba(255,255,255,.1)}
.breadcrumb-nav .breadcrumb{font-size:.85rem;color:rgba(255,255,255,.6)}
.breadcrumb-nav .breadcrumb a{color:rgba(255,255,255,.8);transition:color .3s}
.breadcrumb-nav .breadcrumb a:hover{color:var(--red)}
.breadcrumb-nav .breadcrumb span{margin:0 6px;color:rgba(255,255,255,.4)}

/* ---- 页脚法律链接 ---- */
.footer-legal{display:flex;justify-content:center;gap:24px;padding:16px 0;border-top:1px solid rgba(255,255,255,.1);margin-top:20px}
.footer-legal a{color:rgba(255,255,255,.5);font-size:.82rem;transition:color .3s}
.footer-legal a:hover{color:var(--red)}

/* ---- 页脚H5标签 ---- */
.footer-col h5{color:var(--white);font-size:1rem;margin-bottom:16px;position:relative;padding-bottom:8px}
.footer-col h5::after{content:"";position:absolute;bottom:0;left:0;width:30px;height:2px;background:var(--red)}

/* ---- 内页通用Hero ---- */
.page-hero{background:var(--navy);padding:48px 0;text-align:center;color:var(--white)}
.page-hero h1{font-size:2.2rem;margin-bottom:10px}
.page-hero p{font-size:1rem;opacity:.8;max-width:700px;margin:0 auto}
.content-section{padding:40px 0}

/* ---- 评论网格4列改为自适应 ---- */
@media(min-width:1025px){.review-grid{grid-template-columns:repeat(4,1fr)}}