/* ============================================
   推特 修车改装视频社区 - 全站样式表
   品牌色系：赛车红 #E63946 / 深海蓝 #1D3557 / 暖橙 #F4A261
   ============================================ */

/* --- Reset & Base --- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;color:#2B2D42;background:#F1FAEE;line-height:1.7;overflow-x:hidden}
a{color:#E63946;text-decoration:none;transition:color .3s}
a:hover{color:#F4A261}
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:#1D3557}

/* --- Container --- */
.container{max-width:1200px;margin:0 auto;padding:0 20px}
.section-title{text-align:center;margin-bottom:40px;font-size:2rem;position:relative;padding-bottom:15px}
.section-title::after{content:"";display:block;width:80px;height:4px;background:linear-gradient(90deg,#E63946,#F4A261);margin:12px auto 0;border-radius:2px}
.section-subtitle{text-align:center;color:#666;font-size:1.05rem;margin-top:-25px;margin-bottom:35px}

/* --- Header / Nav --- */
.site-header{background:#1D3557;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:0 20px;max-width:1200px;margin:0 auto;height:68px}
.logo{display:flex;align-items:center;gap:10px}
.logo img{height:42px;width:auto}
.logo-text{color:#fff;font-size:1.6rem;font-weight:800;letter-spacing:2px}
.logo-text span{color:#E63946}
.main-nav{display:flex;align-items:center;gap:0}
.main-nav a{color:#fff;padding:22px 18px;font-size:.95rem;transition:background .3s,color .3s;display:block}
.main-nav a:hover,.main-nav a.active{background:#E63946;color:#fff}
.mobile-toggle{display:none;background:none;border:none;color:#fff;font-size:1.6rem;cursor:pointer;padding:8px}

/* --- Search Bar --- */
.search-bar{background:#f8f9fa;padding:12px 0;border-bottom:1px solid #e0e0e0}
.search-bar .container{display:flex;justify-content:center}
.search-box{display:flex;max-width:600px;width:100%}
.search-box input{flex:1;padding:10px 18px;border:2px solid #ddd;border-right:none;border-radius:25px 0 0 25px;font-size:.95rem;outline:none;transition:border-color .3s}
.search-box input:focus{border-color:#E63946}
.search-box button{padding:10px 28px;background:linear-gradient(135deg,#E63946,#F4A261);color:#fff;border:none;border-radius:0 25px 25px 0;cursor:pointer;font-size:.95rem;transition:opacity .3s}
.search-box button:hover{opacity:.85}

/* --- Banner / Hero --- */
.hero-banner{position:relative;height:520px;overflow:hidden;display:flex;align-items:center;justify-content:center}
.hero-banner .hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:brightness(.55)}
.hero-content{position:relative;z-index:2;text-align:center;color:#fff;padding:0 20px;max-width:800px}
.hero-content h1{font-size:2.8rem;margin-bottom:16px;text-shadow:0 2px 8px rgba(0,0,0,.5)}
.hero-content h1 span{color:#E63946}
.hero-content p{font-size:1.15rem;margin-bottom:28px;text-shadow:0 1px 4px rgba(0,0,0,.4);line-height:1.8}
.hero-content .hero-tags{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-bottom:24px}
.hero-content .hero-tags span{background:rgba(230,57,70,.85);padding:5px 16px;border-radius:20px;font-size:.85rem}
.btn-primary{display:inline-block;padding:14px 36px;background:linear-gradient(135deg,#E63946,#F4A261);color:#fff;border-radius:30px;font-size:1.05rem;font-weight:600;transition:transform .3s,box-shadow .3s;border:none;cursor:pointer}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(230,57,70,.4);color:#fff}
.btn-outline{display:inline-block;padding:12px 30px;border:2px solid #fff;color:#fff;border-radius:30px;font-size:1rem;transition:all .3s;margin-left:12px}
.btn-outline:hover{background:#fff;color:#1D3557}

/* --- Section Spacing --- */
.section{padding:70px 0}
.section-alt{background:#fff}
.section-dark{background:#1D3557;color:#fff}
.section-dark h2,.section-dark h3,.section-dark h4{color:#fff}
.section-dark .section-title::after{background:linear-gradient(90deg,#E63946,#F4A261)}

/* --- Video Cards --- */
.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:28px}
.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}
.video-card:hover{transform:translateY(-6px);box-shadow:0 12px 32px rgba(0,0,0,.15)}
.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 .5s}
.video-card:hover .video-thumb img{transform:scale(1.08)}
.video-play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:64px;height:64px;background:rgba(230,57,70,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s,transform .3s;z-index:3}
.video-play-btn::after{content:"";display:block;width:0;height:0;border-left:22px solid #fff;border-top:13px solid transparent;border-bottom:13px solid transparent;margin-left:4px}
.video-card:hover .video-play-btn{opacity:1;transform:translate(-50%,-50%) scale(1.1)}
.video-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.75);color:#fff;padding:2px 8px;border-radius:4px;font-size:.8rem;z-index:3}
.video-info{padding:16px 18px}
.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:#888;font-size:.85rem}
.video-meta span{display:flex;align-items:center;gap:4px}
.video-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:10px}
.video-tags span{background:#F1FAEE;color:#1D3557;padding:3px 10px;border-radius:12px;font-size:.78rem}

/* --- Category Tabs --- */
.category-tabs{display:flex;flex-wrap:wrap;justify-content:center;gap:12px;margin-bottom:36px}
.category-tabs .tab{padding:8px 24px;border:2px solid #ddd;border-radius:25px;cursor:pointer;transition:all .3s;font-size:.92rem;background:#fff}
.category-tabs .tab:hover,.category-tabs .tab.active{border-color:#E63946;background:#E63946;color:#fff}

/* --- Expert / Team Cards --- */
.team-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:28px}
.team-card{background:#fff;border-radius:12px;overflow:hidden;text-align:center;box-shadow:0 4px 16px rgba(0,0,0,.08);transition:transform .3s}
.team-card:hover{transform:translateY(-4px)}
.team-card .avatar{width:120px;height:120px;border-radius:50%;object-fit:cover;margin:24px auto 16px;border:4px solid #E63946}
.team-card h4{font-size:1.1rem;margin-bottom:4px}
.team-card .role{color:#E63946;font-size:.88rem;margin-bottom:10px}
.team-card p{padding:0 18px;font-size:.9rem;color:#666;margin-bottom:16px}
.team-card .team-links{display:flex;justify-content:center;gap:10px;padding-bottom:20px}
.team-card .team-links a{padding:6px 16px;border:1px solid #E63946;color:#E63946;border-radius:20px;font-size:.82rem;transition:all .3s}
.team-card .team-links a:hover{background:#E63946;color:#fff}

/* --- FAQ Accordion --- */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:#fff;border-radius:10px;margin-bottom:14px;box-shadow:0 2px 8px rgba(0,0,0,.06);overflow:hidden}
.faq-question{padding:18px 24px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:1rem;transition:background .3s}
.faq-question:hover{background:#f8f8f8}
.faq-question .icon{font-size:1.4rem;transition:transform .3s;color:#E63946}
.faq-question.open .icon{transform:rotate(45deg)}
.faq-answer{padding:0 24px;max-height:0;overflow:hidden;transition:max-height .4s ease,padding .4s ease;font-size:.95rem;color:#555;line-height:1.8}
.faq-answer.open{max-height:500px;padding:0 24px 18px}

/* --- Reviews / Testimonials --- */
.review-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:24px}
.review-card{background:#fff;border-radius:12px;padding:24px;box-shadow:0 4px 16px rgba(0,0,0,.08);position:relative}
.review-card::before{content:"\201C";position:absolute;top:10px;left:16px;font-size:3rem;color:#E63946;opacity:.2;font-family:Georgia,serif}
.review-stars{color:#F4A261;margin-bottom:10px;font-size:1.1rem}
.review-card p{font-size:.95rem;color:#555;margin-bottom:14px;line-height:1.7}
.review-author{display:flex;align-items:center;gap:10px}
.review-author .avatar-sm{width:40px;height:40px;border-radius:50%;background:#E63946;color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:1rem}
.review-author .author-info span{display:block}
.review-author .author-info .name{font-weight:600;font-size:.92rem}
.review-author .author-info .date{font-size:.8rem;color:#999}

/* --- Partner Logo Wall --- */
.partner-wall{display:flex;flex-wrap:wrap;justify-content:center;align-items:center;gap:40px;padding:20px 0}
.partner-wall .partner-item{width:120px;height:60px;background:#f0f0f0;border-radius:8px;display:flex;align-items:center;justify-content:center;font-weight:700;color:#999;font-size:.85rem;transition:all .3s}
.partner-wall .partner-item:hover{background:#E63946;color:#fff;transform:scale(1.05)}

/* --- How-To Guide --- */
.howto-steps{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:28px;counter-reset:step}
.howto-step{background:#fff;border-radius:12px;padding:30px 24px;text-align:center;box-shadow:0 4px 16px rgba(0,0,0,.08);position:relative;counter-increment:step}
.howto-step::before{content:counter(step);display:flex;align-items:center;justify-content:center;width:48px;height:48px;background:linear-gradient(135deg,#E63946,#F4A261);color:#fff;border-radius:50%;font-size:1.3rem;font-weight:700;margin:0 auto 16px}
.howto-step h4{margin-bottom:10px;font-size:1.05rem}
.howto-step p{font-size:.9rem;color:#666}

/* --- Contact Section --- */
.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 16px rgba(0,0,0,.08);text-align:center}
.contact-card h4{margin-bottom:12px;color:#E63946}
.contact-card p{font-size:.92rem;color:#555;margin-bottom:8px}
.contact-card .qr-code{width:140px;height:140px;margin:12px auto;background:#f0f0f0;border-radius:8px;display:flex;align-items:center;justify-content:center}
.contact-card .qr-code img{width:100%;height:100%;object-fit:contain;border-radius:8px}

/* --- Share Buttons --- */
.share-bar{display:flex;flex-wrap:wrap;justify-content:center;gap:12px;padding:20px 0}
.share-btn{display:inline-flex;align-items:center;gap:6px;padding:10px 20px;border-radius:25px;color:#fff;font-size:.9rem;transition:opacity .3s;cursor:pointer;border:none}
.share-btn:hover{opacity:.85;color:#fff}
.share-btn.wechat{background:#07C160}
.share-btn.weibo{background:#E6162D}
.share-btn.douyin{background:#000}
.share-btn.bilibili{background:#00A1D6}

/* --- Footer --- */
.site-footer{background:#0D1B2A;color:#aaa;padding:50px 0 0}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:36px;margin-bottom:36px}
.footer-col h4{color:#fff;margin-bottom:16px;font-size:1.05rem;position:relative;padding-bottom:10px}
.footer-col h4::after{content:"";display:block;width:40px;height:3px;background:#E63946;margin-top:8px;border-radius:2px}
.footer-col p,.footer-col li{font-size:.9rem;margin-bottom:8px;line-height:1.7}
.footer-col a{color:#aaa;transition:color .3s}
.footer-col a:hover{color:#E63946}
.footer-col .footer-logo{display:flex;align-items:center;gap:8px;margin-bottom:12px}
.footer-col .footer-logo img{height:36px}
.footer-col .footer-logo span{color:#fff;font-size:1.3rem;font-weight:700}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:20px 0;text-align:center;font-size:.85rem}
.footer-bottom a{color:#E63946}
.footer-qr{display:flex;gap:20px;margin-top:12px}
.footer-qr .qr-item{text-align:center}
.footer-qr .qr-item img{width:100px;height:100px;border-radius:6px;margin-bottom:6px}
.footer-qr .qr-item span{font-size:.78rem;display:block}

/* --- Breadcrumb --- */
.breadcrumb{padding:14px 0;font-size:.88rem;color:#888}
.breadcrumb a{color:#1D3557}
.breadcrumb a:hover{color:#E63946}
.breadcrumb span{margin:0 6px;color:#ccc}

/* --- AI Module --- */
.ai-features{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:28px}
.ai-card{background:linear-gradient(135deg,#1D3557,#2B4A7A);border-radius:12px;padding:30px;color:#fff;transition:transform .3s}
.ai-card:hover{transform:translateY(-4px)}
.ai-card .ai-icon{width:56px;height:56px;background:linear-gradient(135deg,#E63946,#F4A261);border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:1.5rem;margin-bottom:16px}
.ai-card h4{margin-bottom:10px;font-size:1.1rem}
.ai-card p{font-size:.9rem;color:#ccc;line-height:1.7}

/* --- Community Stats --- */
.stats-bar{display:flex;flex-wrap:wrap;justify-content:center;gap:40px;padding:30px 0}
.stat-item{text-align:center}
.stat-item .stat-num{font-size:2.4rem;font-weight:800;color:#E63946;display:block}
.stat-item .stat-label{font-size:.9rem;color:#666;margin-top:4px}

/* --- Parts Grid --- */
.parts-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:24px}
.part-card{background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 4px 16px rgba(0,0,0,.08);transition:transform .3s}
.part-card:hover{transform:translateY(-4px)}
.part-card img{width:100%;height:180px;object-fit:cover}
.part-card .part-info{padding:14px 16px}
.part-card .part-info h4{font-size:.98rem;margin-bottom:6px}
.part-card .part-info .price{color:#E63946;font-weight:700;font-size:1.1rem}
.part-card .part-info p{font-size:.85rem;color:#888;margin-top:4px}

/* --- MCP Widget --- */
.mcp-widget{background:#fff;border-radius:12px;padding:24px;box-shadow:0 4px 16px rgba(0,0,0,.08);max-width:400px;margin:20px auto}
.mcp-widget h4{margin-bottom:12px;text-align:center}
.mcp-widget .mcp-input{width:100%;padding:10px 14px;border:2px solid #ddd;border-radius:8px;margin-bottom:10px;font-size:.92rem}
.mcp-widget .mcp-btn{width:100%;padding:10px;background:linear-gradient(135deg,#E63946,#F4A261);color:#fff;border:none;border-radius:8px;cursor:pointer;font-size:.95rem}
.mcp-widget .mcp-output{margin-top:12px;padding:12px;background:#f8f9fa;border-radius:8px;min-height:60px;font-size:.88rem;color:#555}

/* --- Responsive --- */
@media(max-width:768px){
  .header-inner{flex-wrap:wrap}
  .main-nav{display:none;flex-direction:column;width:100%;background:#1D3557}
  .main-nav.open{display:flex}
  .main-nav a{padding:14px 20px;border-top:1px solid rgba(255,255,255,.1)}
  .mobile-toggle{display:block}
  .hero-banner{height:400px}
  .hero-content h1{font-size:1.8rem}
  .hero-content p{font-size:.95rem}
  .video-grid{grid-template-columns:1fr}
  .section-title{font-size:1.5rem}
  .section{padding:40px 0}
  .stats-bar{gap:20px}
  .stat-item .stat-num{font-size:1.8rem}
  .footer-grid{grid-template-columns:1fr}
  .team-grid{grid-template-columns:repeat(2,1fr)}
  .ai-features{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .howto-steps{grid-template-columns:1fr}
  .review-grid{grid-template-columns:1fr}
}
@media(max-width:480px){
  .hero-banner{height:320px}
  .hero-content h1{font-size:1.4rem}
  .team-grid{grid-template-columns:1fr}
  .btn-primary{padding:12px 24px;font-size:.92rem}
  .search-box input{padding:8px 14px}
}

/* --- Lazy Load Placeholder --- */
.lazy{opacity:0;transition:opacity .6s ease-in}
.lazy.loaded{opacity:1}

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

/* --- Scrollbar --- */
::-webkit-scrollbar{width:8px}
::-webkit-scrollbar-track{background:#f1f1f1}
::-webkit-scrollbar-thumb{background:#E63946;border-radius:4px}
::-webkit-scrollbar-thumb:hover{background:#c5303d}

/* --- Video Modal --- */
.video-modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,.85);z-index:9999;display:flex;align-items:center;justify-content:center;padding:20px}
.video-modal{background:#1a1a1a;border-radius:16px;max-width:800px;width:100%;overflow:hidden;box-shadow:0 20px 60px rgba(0,0,0,.5)}
.video-modal-header{display:flex;justify-content:space-between;align-items:center;padding:16px 20px;background:#222;border-bottom:1px solid #333}
.video-modal-header h3{color:#fff;font-size:1rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;flex:1;margin-right:12px}
.video-modal-close{background:none;border:none;color:#fff;font-size:1.8rem;cursor:pointer;padding:0 4px;transition:color .3s}
.video-modal-close:hover{color:#E63946}
.video-modal-body{padding:0}
.video-player-wrapper{position:relative;padding-top:56.25%;background:#000}
.video-player{position:absolute;inset:0;width:100%;height:100%}
.video-player-overlay{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;background:rgba(0,0,0,.5)}
.video-player-play-icon{width:72px;height:72px;background:rgba(230,57,70,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;margin-bottom:12px}
.video-player-play-icon::after{content:"";display:block;width:0;height:0;border-left:26px solid #fff;border-top:15px solid transparent;border-bottom:15px solid transparent;margin-left:5px}
.video-player-overlay p{color:#fff;font-size:.95rem}
.video-modal-info{padding:12px 20px;text-align:center;color:#888;font-size:.85rem;border-top:1px solid #333}

/* --- Back to Top --- */
.back-to-top{position:fixed;bottom:30px;right:30px;width:48px;height:48px;background:linear-gradient(135deg,#E63946,#F4A261);color:#fff;border:none;border-radius:50%;font-size:1.2rem;cursor:pointer;opacity:0;visibility:hidden;transition:all .3s;z-index:999;box-shadow:0 4px 12px rgba(230,57,70,.4)}
.back-to-top.show{opacity:1;visibility:visible}
.back-to-top:hover{transform:translateY(-3px);box-shadow:0 6px 20px rgba(230,57,70,.5)}

/* --- FAQ open state --- */
.faq-item.open .faq-answer{max-height:500px;padding:0 24px 18px}
.faq-item.open .faq-question .icon{transform:rotate(45deg)}

/* --- EEAT Authority Badges --- */
.eeat-bar{padding:30px 0;background:#f0f7ff;border-bottom:1px solid #d6e8f7}
.eeat-badges{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.eeat-badge{display:flex;align-items:flex-start;gap:12px;background:#fff;padding:18px 16px;border-radius:10px;box-shadow:0 2px 8px rgba(0,0,0,.06);border-left:4px solid #1D3557}
.eeat-badge .eeat-icon{font-size:1.4rem;flex-shrink:0;margin-top:2px}
.eeat-badge strong{display:block;font-size:.95rem;color:#1D3557;margin-bottom:4px}
.eeat-badge span{font-size:.82rem;color:#666;line-height:1.5}

/* --- Footer Links --- */
.footer-links{text-align:center;padding:16px 0;border-top:1px solid rgba(255,255,255,.15);margin-top:20px}
.footer-links a{color:#ccc;margin:0 12px;font-size:.85rem;transition:color .3s}
.footer-links a:hover{color:#F4A261}
.footer-icp{font-size:.8rem;color:#999;margin-top:6px}

/* --- Responsive EEAT --- */
@media(max-width:768px){
  .eeat-badges{grid-template-columns:repeat(2,1fr);gap:12px}
  .eeat-badge{padding:14px 12px}
}
@media(max-width:480px){
  .eeat-badges{grid-template-columns:1fr}
}