/* ============================================
   17c一起草 - 汽车改装视频社区 全站样式
   品牌色: #1a1f3d(深蓝) #e8651a(橙) #f5f6fa(浅灰)
   ============================================ */
*{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",Arial,sans-serif;color:#2c2c2c;background:#f5f6fa;line-height:1.7}
a{text-decoration:none;color:inherit;transition:color .3s}
a:hover{color:#e8651a}
img{max-width:100%;height:auto;display:block}
ul,ol{list-style:none}
.container{max-width:1200px;margin:0 auto;padding:0 20px}

/* 顶部导航 */
.site-header{background:#1a1f3d;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:0 20px;max-width:1200px;margin:0 auto;height:68px}
.logo-wrap{display:flex;align-items:center;gap:10px}
.logo-wrap img{width:42px;height:42px;border-radius:8px}
.logo-wrap .brand-name{color:#fff;font-size:1.4rem;font-weight:700;letter-spacing:1px}
.logo-wrap .brand-name span{color:#e8651a}
.main-nav{display:flex;gap:0}
.main-nav a{color:#cfd4e6;padding:22px 16px;font-size:.95rem;transition:all .3s;position:relative}
.main-nav a:hover,.main-nav a.active{color:#fff;background:rgba(232,101,26,.15)}
.main-nav a::after{content:'';position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:0;height:3px;background:#e8651a;transition:width .3s}
.main-nav a:hover::after,.main-nav a.active::after{width:60%}
.mobile-toggle{display:none;color:#fff;font-size:1.6rem;cursor:pointer;background:none;border:none}

/* 搜索栏 */
.search-bar{background:#151933;padding:12px 0}
.search-bar .container{display:flex;justify-content:center}
.search-box{display:flex;width:100%;max-width:600px;border-radius:25px;overflow:hidden;box-shadow:0 2px 8px rgba(0,0,0,.2)}
.search-box input{flex:1;padding:10px 20px;border:none;font-size:.95rem;background:#fff;outline:none}
.search-box button{padding:10px 28px;background:#e8651a;color:#fff;border:none;font-size:.95rem;cursor:pointer;transition:background .3s}
.search-box button:hover{background:#d4570f}

/* 英雄横幅 */
.hero-section{position:relative;height:520px;overflow:hidden;background:#1a1f3d}
.hero-section img{width:100%;height:100%;object-fit:cover;opacity:.7}
.hero-overlay{position:absolute;top:0;left:0;right:0;bottom:0;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center;background:linear-gradient(to bottom,rgba(26,31,61,.3),rgba(26,31,61,.8))}
.hero-overlay h1{color:#fff;font-size:2.8rem;margin-bottom:16px;text-shadow:0 2px 8px rgba(0,0,0,.5)}
.hero-overlay h1 span{color:#e8651a}
.hero-overlay p{color:#cfd4e6;font-size:1.15rem;max-width:680px;margin-bottom:24px}
.hero-btn{display:inline-block;padding:12px 36px;background:#e8651a;color:#fff;border-radius:30px;font-size:1rem;font-weight:600;transition:all .3s;box-shadow:0 4px 15px rgba(232,101,26,.4)}
.hero-btn:hover{background:#d4570f;transform:translateY(-2px);color:#fff}

/* 面包屑 */
.breadcrumb{padding:14px 0;font-size:.85rem;color:#888}
.breadcrumb a{color:#e8651a}
.breadcrumb span{margin:0 6px;color:#bbb}

/* 区块通用 */
.section{padding:60px 0}
.section-alt{background:#fff}
.section-dark{background:#1a1f3d;color:#fff}
.section-title{text-align:center;margin-bottom:40px}
.section-title h2{font-size:1.9rem;color:#1a1f3d;margin-bottom:8px;position:relative;display:inline-block}
.section-dark .section-title h2{color:#fff}
.section-title h2::after{content:'';display:block;width:50px;height:3px;background:#e8651a;margin:10px auto 0}
.section-title p{color:#777;font-size:1rem;margin-top:6px}
.section-dark .section-title p{color:#aab}

/* 视频卡片网格 */
.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:all .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:#222}
.video-thumb img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;transition:transform .5s}
.video-card:hover .video-thumb img{transform:scale(1.08)}
.play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:60px;height:60px;background:rgba(232,101,26,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s;pointer-events:none}
.play-btn::after{content:'';border-left:20px solid #fff;border-top:12px solid transparent;border-bottom:12px solid transparent;margin-left:4px}
.video-card:hover .play-btn{opacity:1}
.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}
.video-info{padding:14px 16px}
.video-info h3{font-size:1rem;color:#1a1f3d;margin-bottom:6px;line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.video-meta{display:flex;gap:12px;font-size:.8rem;color:#999}
.video-meta span{display:flex;align-items:center;gap:3px}
.video-tags{display:flex;gap:6px;margin-top:8px;flex-wrap:wrap}
.video-tags span{background:#f0f1f5;color:#666;padding:2px 10px;border-radius:12px;font-size:.75rem}

/* 专家卡片 */
.expert-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:28px}
.expert-card{background:#fff;border-radius:12px;padding:28px;text-align:center;box-shadow:0 4px 16px rgba(0,0,0,.08);transition:all .3s}
.expert-card:hover{transform:translateY(-4px);box-shadow:0 8px 24px rgba(0,0,0,.12)}
.expert-card img{width:120px;height:120px;border-radius:50%;margin:0 auto 16px;object-fit:cover;border:3px solid #e8651a}
.expert-card h3{font-size:1.15rem;color:#1a1f3d;margin-bottom:4px}
.expert-card .role{color:#e8651a;font-size:.9rem;margin-bottom:10px}
.expert-card p{color:#666;font-size:.9rem;line-height:1.6;margin-bottom:14px}
.expert-card .awards{color:#999;font-size:.82rem;margin-bottom:14px}
.expert-btns{display:flex;gap:10px;justify-content:center}
.expert-btns a{padding:8px 20px;border-radius:20px;font-size:.85rem;transition:all .3s}
.btn-primary{background:#e8651a;color:#fff}
.btn-primary:hover{background:#d4570f;color:#fff}
.btn-outline{border:1px solid #e8651a;color:#e8651a}
.btn-outline:hover{background:#e8651a;color:#fff}

/* FAQ */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:#fff;border-radius:10px;margin-bottom:12px;box-shadow:0 2px 8px rgba(0,0,0,.06);overflow:hidden}
.faq-question{padding:18px 24px;font-size:1rem;font-weight:600;color:#1a1f3d;cursor:pointer;display:flex;justify-content:space-between;align-items:center;transition:background .3s}
.faq-question:hover{background:#f8f9fc}
.faq-question::after{content:'+';font-size:1.4rem;color:#e8651a;transition:transform .3s}
.faq-item.active .faq-question::after{transform:rotate(45deg)}
.faq-answer{padding:0 24px;max-height:0;overflow:hidden;transition:all .4s;color:#555;font-size:.95rem;line-height:1.7}
.faq-item.active .faq-answer{padding:0 24px 18px;max-height:500px}

/* 用户评论 */
.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 4px 12px rgba(0,0,0,.06)}
.review-card .stars{color:#e8651a;font-size:1.1rem;margin-bottom:8px}
.review-card p{color:#555;font-size:.92rem;line-height:1.6;margin-bottom:12px;font-style:italic}
.review-card .reviewer{display:flex;align-items:center;gap:10px}
.reviewer-avatar{width:36px;height:36px;border-radius:50%;background:#e8651a;color:#fff;display:flex;align-items:center;justify-content:center;font-size:.85rem;font-weight:700}
.reviewer-info .name{font-size:.88rem;color:#1a1f3d;font-weight:600}
.reviewer-info .date{font-size:.78rem;color:#999}

/* 合作品牌墙 */
.brand-wall{display:flex;flex-wrap:wrap;justify-content:center;gap:30px;align-items:center}
.brand-wall .brand-item{width:140px;height:80px;background:#fff;border-radius:10px;display:flex;align-items:center;justify-content:center;box-shadow:0 2px 8px rgba(0,0,0,.06);padding:12px;font-size:1rem;color:#555;font-weight:700;transition:all .3s}
.brand-wall .brand-item:hover{box-shadow:0 4px 16px rgba(0,0,0,.12);transform:scale(1.05)}

/* 联系我们 */
.contact-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:28px}
.contact-card{background:#fff;border-radius:12px;padding:28px;box-shadow:0 4px 12px rgba(0,0,0,.06)}
.contact-card h3{color:#1a1f3d;font-size:1.1rem;margin-bottom:14px;padding-bottom:10px;border-bottom:2px solid #e8651a}
.contact-card .info-row{display:flex;align-items:flex-start;gap:10px;margin-bottom:10px;font-size:.92rem;color:#555}
.contact-card .info-row strong{color:#1a1f3d;min-width:70px}

/* 社交分享 */
.share-bar{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;padding:20px 0}
.share-btn{display:inline-flex;align-items:center;gap:6px;padding:10px 22px;border-radius:25px;font-size:.9rem;color:#fff;transition:all .3s;cursor:pointer}
.share-btn:hover{transform:translateY(-2px);color:#fff}
.share-wechat{background:#07c160}
.share-weibo{background:#e6162d}
.share-douyin{background:#161823}
.share-bilibili{background:#00a1d6}

/* How-To 指南 */
.howto-steps{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:24px;margin-top:30px}
.howto-step{text-align:center;padding:24px;background:#fff;border-radius:12px;box-shadow:0 4px 12px rgba(0,0,0,.06)}
.step-num{width:48px;height:48px;background:#e8651a;color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.3rem;font-weight:700;margin:0 auto 14px}
.howto-step h4{color:#1a1f3d;margin-bottom:8px;font-size:1rem}
.howto-step p{color:#666;font-size:.9rem}

/* AI赋能区块 */
.ai-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:24px}
.ai-card{background:linear-gradient(135deg,#1a1f3d 0%,#2a3060 100%);border-radius:14px;padding:30px;color:#fff;transition:all .3s}
.ai-card:hover{transform:translateY(-4px);box-shadow:0 8px 30px rgba(26,31,61,.4)}
.ai-card h3{font-size:1.15rem;margin-bottom:10px;color:#e8651a}
.ai-card p{color:#bbc;font-size:.92rem;line-height:1.6}

/* 社区分类 */
.community-cats{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:16px}
.cat-card{background:#fff;border-radius:12px;padding:20px;text-align:center;box-shadow:0 3px 10px rgba(0,0,0,.06);transition:all .3s}
.cat-card:hover{border-color:#e8651a;transform:translateY(-3px);box-shadow:0 6px 20px rgba(0,0,0,.1)}
.cat-card .cat-icon{font-size:2rem;margin-bottom:8px}
.cat-card h4{color:#1a1f3d;font-size:.95rem;margin-bottom:4px}
.cat-card p{color:#999;font-size:.8rem}

/* 页脚 */
.site-footer{background:#111428;color:#8890a8;padding:50px 0 0}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:30px;padding-bottom:30px;border-bottom:1px solid #1e2340}
.footer-col h4{color:#fff;font-size:1rem;margin-bottom:14px;position:relative;padding-bottom:8px}
.footer-col h4::after{content:'';position:absolute;bottom:0;left:0;width:30px;height:2px;background:#e8651a}
.footer-col p,.footer-col a{font-size:.88rem;color:#8890a8;display:block;margin-bottom:6px;transition:color .3s}
.footer-col a:hover{color:#e8651a}
.footer-col img{border-radius:8px;margin-top:6px}
.footer-qr{display:flex;gap:16px;margin-top:10px}
.footer-qr div{text-align:center}
.footer-qr img{width:110px;height:110px}
.footer-qr p{font-size:.78rem;margin-top:4px;color:#8890a8}
.footer-bottom{text-align:center;padding:20px 0;font-size:.82rem;color:#5a6080}
.footer-bottom a{color:#e8651a}

/* MCP前端占位 */
.mcp-widget{background:#1e2340;border-radius:8px;padding:16px;margin-top:16px;text-align:center;font-size:.82rem;color:#5a6080;border:1px dashed #2a3060}

/* 内页通用 */
.page-header{background:linear-gradient(135deg,#1a1f3d,#2a3060);padding:60px 0 40px;text-align:center;color:#fff}
.page-header h1{font-size:2.2rem;margin-bottom:8px}
.page-header h1 span{color:#e8651a}
.page-header p{color:#aab;font-size:1rem}
.page-content{padding:40px 0 60px}

/* 标签云 */
.tag-cloud{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-top:20px}
.tag-cloud a{background:#f0f1f5;color:#555;padding:6px 16px;border-radius:20px;font-size:.85rem;transition:all .3s}
.tag-cloud a:hover{background:#e8651a;color:#fff}

/* 干扰标签隐藏 */
.jrb{position:absolute;width:0;height:0;overflow:hidden;opacity:0;pointer-events:none;z-index:-9999}

/* 响应式 */
@media(max-width:768px){
  .header-inner{padding:0 12px}
  .main-nav{display:none;position:absolute;top:68px;left:0;right:0;background:#1a1f3d;flex-direction:column;box-shadow:0 8px 20px rgba(0,0,0,.3)}
  .main-nav.open{display:flex}
  .main-nav a{padding:14px 20px;border-bottom:1px solid #252a4a}
  .mobile-toggle{display:block}
  .hero-section{height:360px}
  .hero-overlay h1{font-size:1.8rem}
  .hero-overlay p{font-size:.95rem;padding:0 20px}
  .section{padding:40px 0}
  .section-title h2{font-size:1.5rem}
  .video-grid{grid-template-columns:1fr}
  .expert-grid{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .ai-grid{grid-template-columns:1fr}
  .community-cats{grid-template-columns:repeat(2,1fr)}
  .review-grid{grid-template-columns:1fr}
}
@media(max-width:480px){
  .hero-section{height:280px}
  .hero-overlay h1{font-size:1.4rem}
  .search-box{margin:0 10px}
  .community-cats{grid-template-columns:1fr}
}