/* ============================================
   91 修车改装视频社区 - 全站样式表
   品牌色: #C41E3A (深红) #1A1A2E (深蓝黑) #E8E8E8 (浅灰)
   ============================================ */

/* 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:#222;background:#0D0D14;line-height:1.7;overflow-x:hidden}
a{color:#C41E3A;text-decoration:none;transition:color .3s}
a:hover{color:#E8453A}
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:#fff}

/* Container */
.container{max-width:1200px;margin:0 auto;padding:0 20px}
.section-padding{padding:60px 0}

/* ============ Header & Navigation ============ */
.site-header{background:#0D0D14;position:sticky;top:0;z-index:1000;border-bottom:1px solid rgba(196,30,58,.3);backdrop-filter:blur(10px)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;max-width:1200px;margin:0 auto}
.logo-link{display:flex;align-items:center;gap:10px}
.logo-link img{height:48px;width:auto}
.logo-text{font-size:1.5rem;font-weight:900;color:#C41E3A;letter-spacing:2px}
.main-nav{display:flex;align-items:center;gap:0}
.main-nav a{color:#ccc;padding:10px 16px;font-size:.95rem;transition:all .3s;position:relative}
.main-nav a:hover,.main-nav a.active{color:#C41E3A}
.main-nav a::after{content:'';position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:0;height:2px;background:#C41E3A;transition:width .3s}
.main-nav a:hover::after,.main-nav a.active::after{width:60%}
.mobile-toggle{display:none;background:none;border:none;color:#fff;font-size:1.5rem;cursor:pointer}

/* Search Bar */
.search-bar{background:#12121E;padding:10px 0;border-bottom:1px solid #1e1e30}
.search-bar .container{display:flex;justify-content:center}
.search-box{display:flex;max-width:560px;width:100%}
.search-box input{flex:1;padding:10px 18px;border:1px solid #333;border-right:none;border-radius:4px 0 0 4px;background:#1A1A2E;color:#fff;font-size:.9rem;outline:none;transition:border-color .3s}
.search-box input:focus{border-color:#C41E3A}
.search-box button{padding:10px 24px;background:#C41E3A;color:#fff;border:none;border-radius:0 4px 4px 0;cursor:pointer;font-size:.9rem;transition:background .3s}
.search-box button:hover{background:#a0182e}

/* ============ Banner ============ */
.hero-banner{position:relative;height:520px;overflow:hidden;display:flex;align-items:center;justify-content:center}
.hero-banner .banner-bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:brightness(.45)}
.hero-banner .banner-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(13,13,20,.3) 0%,rgba(13,13,20,.85) 100%)}
.hero-content{position:relative;z-index:2;text-align:center;max-width:800px;padding:0 20px}
.hero-content h1{font-size:2.8rem;margin-bottom:16px;text-shadow:0 2px 20px rgba(0,0,0,.5)}
.hero-content h1 span{color:#C41E3A}
.hero-content p{font-size:1.15rem;color:#bbb;margin-bottom:24px;line-height:1.8}
.hero-content .hero-tags{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}
.hero-tag{background:rgba(196,30,58,.15);border:1px solid rgba(196,30,58,.4);color:#E8453A;padding:6px 16px;border-radius:20px;font-size:.85rem}

/* ============ Section Titles ============ */
.section-title{text-align:center;margin-bottom:40px}
.section-title h2{font-size:2rem;color:#fff;margin-bottom:10px}
.section-title h2 span{color:#C41E3A}
.section-title p{color:#888;font-size:1rem}
.section-title .title-line{width:60px;height:3px;background:#C41E3A;margin:12px auto 0}

/* ============ Video Cards ============ */
.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:24px}
.video-card{background:#151520;border-radius:10px;overflow:hidden;transition:transform .3s,box-shadow .3s;cursor:pointer}
.video-card:hover{transform:translateY(-6px);box-shadow:0 12px 30px rgba(196,30,58,.15)}
.video-thumb{position:relative;padding-top:56.25%;overflow:hidden}
.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(1.05)}
.play-btn{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s;background:rgba(0,0,0,.4)}
.video-card:hover .play-btn{opacity:1}
.play-btn span{width:56px;height:56px;background:rgba(196,30,58,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:0}
.play-btn span::after{content:'';border-style:solid;border-width:10px 0 10px 18px;border-color:transparent transparent transparent #fff;margin-left:3px}
.video-info{padding:14px 16px}
.video-info h3{font-size:1rem;color:#eee;margin-bottom:6px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.video-info .video-meta{display:flex;gap:14px;font-size:.8rem;color:#777}
.video-info .video-meta span{display:flex;align-items:center;gap:4px}
.video-tags{display:flex;gap:6px;margin-top:8px;flex-wrap:wrap}
.video-tags span{background:#1e1e30;color:#aaa;padding:2px 10px;border-radius:12px;font-size:.75rem}

/* ============ Short Video Section ============ */
.short-video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:16px}
.short-card{position:relative;border-radius:10px;overflow:hidden;padding-top:160%;background:#151520}
.short-card img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.short-card .short-overlay{position:absolute;bottom:0;left:0;right:0;padding:12px;background:linear-gradient(transparent,rgba(0,0,0,.8))}
.short-card .short-overlay p{color:#fff;font-size:.85rem}
.short-card .short-play{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s}
.short-card:hover .short-play{opacity:1}
.short-card .short-play span{width:44px;height:44px;background:rgba(196,30,58,.85);border-radius:50%;display:flex;align-items:center;justify-content:center}
.short-card .short-play span::after{content:'';border-style:solid;border-width:8px 0 8px 14px;border-color:transparent transparent transparent #fff;margin-left:2px}

/* ============ AI Section ============ */
.ai-section{background:linear-gradient(135deg,#0D0D14 0%,#1A1A2E 100%)}
.ai-features{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:24px}
.ai-card{background:rgba(255,255,255,.03);border:1px solid rgba(196,30,58,.2);border-radius:12px;padding:30px;text-align:center;transition:all .3s}
.ai-card:hover{border-color:#C41E3A;background:rgba(196,30,58,.05)}
.ai-card .ai-icon{width:64px;height:64px;margin:0 auto 16px;background:linear-gradient(135deg,#C41E3A,#E8453A);border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:1.8rem}
.ai-card h3{color:#eee;font-size:1.1rem;margin-bottom:10px}
.ai-card p{color:#888;font-size:.9rem;line-height:1.6}

/* ============ Expert Section ============ */
.expert-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:24px}
.expert-card{background:#151520;border-radius:12px;overflow:hidden;text-align:center;padding:30px 20px;transition:transform .3s}
.expert-card:hover{transform:translateY(-4px)}
.expert-card img{width:100px;height:100px;border-radius:50%;object-fit:cover;margin:0 auto 16px;border:3px solid #C41E3A}
.expert-card h3{color:#eee;font-size:1.05rem;margin-bottom:4px}
.expert-card .expert-role{color:#C41E3A;font-size:.85rem;margin-bottom:10px}
.expert-card p{color:#888;font-size:.85rem;line-height:1.6;margin-bottom:14px}
.expert-card .expert-btns{display:flex;gap:8px;justify-content:center}
.btn-sm{padding:6px 16px;border-radius:20px;font-size:.8rem;border:1px solid #C41E3A;color:#C41E3A;transition:all .3s;cursor:pointer;background:transparent}
.btn-sm:hover{background:#C41E3A;color:#fff}
.btn-primary{background:#C41E3A;color:#fff;border:1px solid #C41E3A;padding:10px 28px;border-radius:6px;font-size:.95rem;cursor:pointer;transition:all .3s}
.btn-primary:hover{background:#a0182e}

/* ============ Brand Wall ============ */
.brand-wall{display:flex;flex-wrap:wrap;gap:20px;justify-content:center;align-items:center}
.brand-wall .brand-item{background:#151520;border:1px solid #222;border-radius:8px;padding:16px 28px;color:#888;font-size:1rem;font-weight:600;transition:all .3s}
.brand-wall .brand-item:hover{border-color:#C41E3A;color:#C41E3A}

/* ============ FAQ Section ============ */
.faq-section{background:#0D0D14}
.faq-list{max-width:800px;margin:0 auto}
.faq-item{border:1px solid #1e1e30;border-radius:8px;margin-bottom:12px;overflow:hidden}
.faq-question{padding:16px 20px;background:#151520;color:#eee;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-size:.95rem;transition:background .3s}
.faq-question:hover{background:#1a1a2e}
.faq-question .faq-arrow{transition:transform .3s;color:#C41E3A;font-size:1.2rem}
.faq-item.active .faq-arrow{transform:rotate(180deg)}
.faq-answer{padding:0 20px;max-height:0;overflow:hidden;transition:all .3s;color:#999;font-size:.9rem;line-height:1.7}
.faq-item.active .faq-answer{padding:16px 20px;max-height:300px}

/* ============ Reviews ============ */
.review-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}
.review-card{background:#151520;border-radius:10px;padding:24px;border:1px solid #1e1e30}
.review-card .review-stars{color:#FFB800;font-size:1rem;margin-bottom:10px;letter-spacing:2px}
.review-card p{color:#bbb;font-size:.9rem;line-height:1.7;margin-bottom:12px;font-style:italic}
.review-card .reviewer{display:flex;align-items:center;gap:10px}
.review-card .reviewer .avatar{width:36px;height:36px;border-radius:50%;background:#C41E3A;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:.85rem}
.review-card .reviewer .name{color:#eee;font-size:.85rem}
.review-card .reviewer .date{color:#666;font-size:.75rem}

/* ============ How-To Guide ============ */
.howto-steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:24px;margin-top:30px}
.howto-step{text-align:center;padding:24px}
.howto-step .step-num{width:48px;height:48px;background:#C41E3A;border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-size:1.2rem;font-weight:700;margin:0 auto 14px}
.howto-step h4{color:#eee;margin-bottom:8px}
.howto-step p{color:#888;font-size:.88rem}

/* ============ Contact Section ============ */
.contact-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px}
.contact-card{background:#151520;border-radius:10px;padding:24px;border:1px solid #1e1e30}
.contact-card h3{color:#eee;font-size:1.05rem;margin-bottom:12px;display:flex;align-items:center;gap:8px}
.contact-card h3 .icon{color:#C41E3A}
.contact-card p{color:#999;font-size:.9rem;line-height:1.8}
.contact-card a{color:#C41E3A}

/* ============ Share Buttons ============ */
.share-bar{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin-top:20px}
.share-btn{padding:8px 20px;border-radius:20px;font-size:.85rem;color:#fff;border:none;cursor:pointer;transition:opacity .3s}
.share-btn:hover{opacity:.85}
.share-wechat{background:#07C160}
.share-weibo{background:#E6162D}
.share-douyin{background:#161823}
.share-bilibili{background:#00A1D6}

/* ============ Footer ============ */
.site-footer{background:#08080F;border-top:1px solid #1e1e30;padding:40px 0 20px}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:30px;margin-bottom:30px}
.footer-col h4{color:#eee;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:#C41E3A}
.footer-col p,.footer-col a{color:#888;font-size:.85rem;line-height:2}
.footer-col a:hover{color:#C41E3A}
.footer-col .footer-logo{height:40px;margin-bottom:10px}
.footer-qr{display:flex;gap:16px;margin-top:10px}
.footer-qr img{width:100px;height:100px;border-radius:6px}
.footer-bottom{text-align:center;padding-top:20px;border-top:1px solid #1e1e30;color:#666;font-size:.8rem}
.footer-bottom a{color:#888}
.footer-update{color:#555;font-size:.78rem;margin-top:6px}

/* ============ Breadcrumb ============ */
.breadcrumb{padding:14px 0;font-size:.85rem;color:#888}
.breadcrumb a{color:#999}
.breadcrumb a:hover{color:#C41E3A}
.breadcrumb span{margin:0 6px;color:#555}

/* ============ Inner Page ============ */
.page-hero{background:#12121E;padding:50px 0;text-align:center}
.page-hero h1{font-size:2rem;margin-bottom:8px}
.page-hero p{color:#888}
.content-section{background:#0D0D14;padding:40px 0}
.content-section p{color:#bbb;line-height:1.8;margin-bottom:16px}
.content-section h2{color:#fff;margin-bottom:16px;font-size:1.5rem}
.content-section h3{color:#eee;margin-bottom:12px;font-size:1.2rem}

/* ============ MCP Widget ============ */
.mcp-widget{background:#151520;border:1px solid #1e1e30;border-radius:10px;padding:20px;margin-top:20px}
.mcp-widget h4{color:#eee;margin-bottom:10px}
.mcp-widget .mcp-input{display:flex;gap:8px}
.mcp-widget input{flex:1;padding:8px 14px;background:#1A1A2E;border:1px solid #333;border-radius:4px;color:#fff;outline:none}
.mcp-widget button{padding:8px 18px;background:#C41E3A;color:#fff;border:none;border-radius:4px;cursor:pointer}

/* ============ Responsive ============ */
@media(max-width:768px){
  .header-inner{flex-wrap:wrap}
  .main-nav{display:none;flex-direction:column;width:100%;padding:10px 0}
  .main-nav.show{display:flex}
  .mobile-toggle{display:block}
  .hero-banner{height:380px}
  .hero-content h1{font-size:1.8rem}
  .video-grid{grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}
  .short-video-grid{grid-template-columns:repeat(auto-fill,minmax(140px,1fr))}
  .section-padding{padding:40px 0}
  .footer-grid{grid-template-columns:1fr}
  .search-box{max-width:100%}
}
@media(max-width:480px){
  .hero-content h1{font-size:1.4rem}
  .hero-content p{font-size:.95rem}
  .video-grid{grid-template-columns:1fr}
  .section-title h2{font-size:1.5rem}
}

/* Lazy Load */
img[data-src]{opacity:0;transition:opacity .4s}
img.loaded{opacity:1}

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

/* ============ Community Modules ============ */
.community-modules{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:24px}
.community-module{background:rgba(255,255,255,.03);border:1px solid rgba(196,30,58,.15);border-radius:12px;padding:28px;text-align:center;transition:all .3s}
.community-module:hover{border-color:#C41E3A;background:rgba(196,30,58,.05);transform:translateY(-4px)}
.community-module .module-icon{font-size:2.4rem;margin-bottom:14px;display:block}
.community-module h3{color:#eee;font-size:1.05rem;margin-bottom:10px}
.community-module p{color:#888;font-size:.88rem;line-height:1.7}

/* ============ Trust / EEAT Section ============ */
.trust-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:24px}
.trust-card{background:#151520;border:1px solid #1e1e30;border-radius:12px;padding:28px;text-align:center;transition:all .3s}
.trust-card:hover{border-color:#C41E3A;transform:translateY(-4px)}
.trust-card .trust-icon{font-size:2.4rem;margin-bottom:14px;display:block}
.trust-card h4{color:#eee;font-size:1.05rem;margin-bottom:10px}
.trust-card p{color:#888;font-size:.88rem;line-height:1.7}

/* ============ Expert Certification Badge ============ */
.expert-cert{color:#4CAF50;font-size:.8rem;margin-bottom:10px;font-weight:600}

/* ============ Video Duration Tag ============ */
.video-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.8);color:#fff;padding:2px 8px;border-radius:4px;font-size:.75rem;font-weight:600;z-index:2}

/* ============ Content Section Enhancements ============ */
.content-section h2{padding-top:20px;border-top:1px solid #1e1e30;margin-top:20px}
.content-section h2:first-child{border-top:none;margin-top:0;padding-top:0}

/* ============ Responsive Additions ============ */
@media(max-width:768px){
  .community-modules{grid-template-columns:1fr 1fr}
  .trust-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:480px){
  .community-modules{grid-template-columns:1fr}
  .trust-grid{grid-template-columns:1fr}
}