/* ============================================
   困困兔 - 汽车改装视频社区 全站样式
   品牌色: #C41E3A (赛车红) #1A1A2E (深夜蓝) #E8E8E8 (银灰)
   ax2a8b.cn
   ============================================ */

/* === 基础重置 === */
*,*::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:#2D2D2D;background:#0D0D1A;line-height:1.7;overflow-x:hidden}
a{text-decoration:none;color:inherit;transition:color .3s}
ul,ol{list-style:none}
img{max-width:100%;height:auto;display:block}
h1,h2,h3,h4,h5,h6{font-weight:700;line-height:1.3}

/* === 颜色变量 === */
:root{
  --red:#C41E3A;
  --red-dark:#9B1830;
  --red-light:#E8344F;
  --dark:#1A1A2E;
  --dark2:#16213E;
  --dark3:#0F3460;
  --silver:#E8E8E8;
  --silver2:#B0B0B0;
  --white:#FFFFFF;
  --gold:#F5A623;
  --gradient-red:linear-gradient(135deg,#C41E3A 0%,#E8344F 100%);
  --gradient-dark:linear-gradient(180deg,#1A1A2E 0%,#0D0D1A 100%);
  --shadow-card:0 8px 32px rgba(0,0,0,.35);
  --shadow-hover:0 12px 48px rgba(196,30,58,.25);
  --radius:12px;
  --radius-lg:20px;
}

/* === 容器 === */
.container{width:100%;max-width:1280px;margin:0 auto;padding:0 20px}
.container-wide{width:100%;max-width:1440px;margin:0 auto;padding:0 20px}

/* === 头部导航 === */
.site-header{position:fixed;top:0;left:0;width:100%;z-index:1000;background:rgba(26,26,46,.92);backdrop-filter:blur(16px);border-bottom:1px solid rgba(196,30,58,.2);transition:all .3s}
.site-header.scrolled{background:rgba(13,13,26,.98);box-shadow:0 4px 20px rgba(0,0,0,.5)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:72px;max-width:1440px;margin:0 auto;padding:0 24px}
.logo-wrap{display:flex;align-items:center;gap:10px}
.logo-wrap img{height:46px;width:auto}
.logo-text{font-size:1.4rem;font-weight:800;color:var(--white);letter-spacing:1px}
.logo-text span{color:var(--red)}

.main-nav{display:flex;align-items:center;gap:6px}
.main-nav a{color:var(--silver);font-size:.95rem;padding:8px 14px;border-radius:8px;transition:all .3s;position:relative;font-weight:500}
.main-nav a:hover,.main-nav a.active{color:var(--white);background:rgba(196,30,58,.15)}
.main-nav a.active::after{content:'';position:absolute;bottom:2px;left:50%;transform:translateX(-50%);width:20px;height:3px;background:var(--red);border-radius:2px}

.mobile-toggle{display:none;flex-direction:column;gap:5px;cursor:pointer;padding:8px}
.mobile-toggle span{width:26px;height:2.5px;background:var(--white);border-radius:2px;transition:all .3s}

/* === 搜索栏 === */
.search-bar{background:rgba(26,26,46,.85);border-bottom:1px solid rgba(255,255,255,.06);padding:12px 0;margin-top:72px}
.search-bar-inner{max-width:680px;margin:0 auto;position:relative;padding:0 20px}
.search-bar input{width:100%;height:46px;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.12);border-radius:24px;padding:0 50px 0 20px;color:var(--white);font-size:.95rem;outline:none;transition:all .3s}
.search-bar input::placeholder{color:var(--silver2)}
.search-bar input:focus{border-color:var(--red);background:rgba(255,255,255,.12);box-shadow:0 0 0 3px rgba(196,30,58,.15)}
.search-bar button{position:absolute;right:28px;top:50%;transform:translateY(-50%);background:var(--red);border:none;width:36px;height:36px;border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .3s}
.search-bar button:hover{background:var(--red-light);transform:translateY(-50%) scale(1.05)}
.search-bar button svg{width:18px;height:18px;fill:var(--white)}

/* === Hero Banner === */
.hero{position:relative;min-height:85vh;display:flex;align-items:center;overflow:hidden;background:var(--dark)}
.hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:brightness(.45)}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(13,13,26,.3) 0%,rgba(13,13,26,.85) 100%)}
.hero-content{position:relative;z-index:2;text-align:center;width:100%;padding:60px 20px}
.hero h1{font-size:3.2rem;color:var(--white);margin-bottom:16px;text-shadow:0 4px 20px rgba(0,0,0,.5)}
.hero h1 span{color:var(--red)}
.hero .hero-sub{font-size:1.25rem;color:var(--silver);margin-bottom:32px;max-width:700px;margin-left:auto;margin-right:auto}
.hero-tags{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-bottom:36px}
.hero-tags span{background:rgba(196,30,58,.2);color:var(--red-light);padding:6px 16px;border-radius:20px;font-size:.85rem;border:1px solid rgba(196,30,58,.3)}
.hero-btns{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}

/* === 按钮 === */
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;border-radius:30px;font-size:1rem;font-weight:600;cursor:pointer;border:none;transition:all .3s}
.btn-primary{background:var(--gradient-red);color:var(--white);box-shadow:0 4px 20px rgba(196,30,58,.4)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 30px rgba(196,30,58,.5)}
.btn-outline{background:transparent;color:var(--white);border:2px solid rgba(255,255,255,.3)}
.btn-outline:hover{border-color:var(--red);color:var(--red)}
.btn-sm{padding:10px 22px;font-size:.9rem}
.btn-gold{background:linear-gradient(135deg,#F5A623,#F7C948);color:#1A1A2E}

/* === 区块通用 === */
.section{padding:80px 0}
.section-dark{background:var(--gradient-dark)}
.section-darker{background:#0A0A16}
.section-alt{background:linear-gradient(180deg,#0D0D1A 0%,#1A1A2E 100%)}
.section-header{text-align:center;margin-bottom:50px}
.section-header h2{font-size:2.2rem;color:var(--white);margin-bottom:12px}
.section-header h2 span{color:var(--red)}
.section-header p{color:var(--silver2);font-size:1.05rem;max-width:600px;margin:0 auto}
.section-header .tag{display:inline-block;background:rgba(196,30,58,.15);color:var(--red);padding:4px 14px;border-radius:16px;font-size:.8rem;margin-bottom:12px;border:1px solid rgba(196,30,58,.25)}

/* === 视频卡片 === */
.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:24px}
.video-card{background:rgba(255,255,255,.04);border-radius:var(--radius);overflow:hidden;border:1px solid rgba(255,255,255,.06);transition:all .4s;cursor:pointer;position:relative}
.video-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-hover);border-color:rgba(196,30,58,.3)}
.video-card .thumb{position:relative;padding-top:56.25%;overflow:hidden}
.video-card .thumb img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;transition:transform .5s}
.video-card:hover .thumb img{transform:scale(1.08)}
.video-card .play-btn{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%) scale(0);width:64px;height:64px;background:rgba(196,30,58,.9);border-radius:50%;display:flex;align-items:center;justify-content:center;transition:all .4s;opacity:0}
.video-card:hover .play-btn{transform:translate(-50%,-50%) scale(1);opacity:1}
.video-card .play-btn svg{width:28px;height:28px;fill:var(--white);margin-left:4px}
.video-card .duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.8);color:var(--white);padding:2px 8px;border-radius:4px;font-size:.75rem}
.video-card .card-body{padding:16px}
.video-card .card-body h3{font-size:1.05rem;color:var(--white);margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.video-card .card-meta{display:flex;align-items:center;gap:12px;color:var(--silver2);font-size:.8rem}
.video-card .card-meta span{display:flex;align-items:center;gap:4px}
.video-card .card-tags{display:flex;gap:6px;margin-top:10px;flex-wrap:wrap}
.video-card .card-tags span{background:rgba(196,30,58,.12);color:var(--red-light);padding:2px 10px;border-radius:12px;font-size:.75rem}

/* === 分类标签栏 === */
.tab-nav{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin-bottom:36px}
.tab-nav .tab{padding:8px 20px;border-radius:20px;background:rgba(255,255,255,.06);color:var(--silver2);cursor:pointer;transition:all .3s;font-size:.9rem;border:1px solid transparent}
.tab-nav .tab:hover,.tab-nav .tab.active{background:rgba(196,30,58,.2);color:var(--red-light);border-color:rgba(196,30,58,.3)}

/* === AI赋能区 === */
.ai-section{position:relative;overflow:hidden}
.ai-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px}
.ai-card{background:linear-gradient(145deg,rgba(15,52,96,.4),rgba(26,26,46,.6));border:1px solid rgba(196,30,58,.15);border-radius:var(--radius-lg);padding:32px;transition:all .4s;position:relative;overflow:hidden}
.ai-card::before{content:'';position:absolute;top:-50%;right:-50%;width:100%;height:100%;background:radial-gradient(circle,rgba(196,30,58,.08) 0%,transparent 70%);transition:all .5s}
.ai-card:hover::before{top:-30%;right:-30%}
.ai-card:hover{border-color:rgba(196,30,58,.4);transform:translateY(-4px)}
.ai-card .icon{width:56px;height:56px;background:var(--gradient-red);border-radius:14px;display:flex;align-items:center;justify-content:center;margin-bottom:20px}
.ai-card .icon svg{width:28px;height:28px;fill:var(--white)}
.ai-card h4{color:var(--white);font-size:1.15rem;margin-bottom:10px}
.ai-card p{color:var(--silver2);font-size:.9rem;line-height:1.6}

/* === 社区模块 === */
.community-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:20px}
.community-card{background:rgba(255,255,255,.03);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);padding:24px;text-align:center;transition:all .4s}
.community-card:hover{background:rgba(196,30,58,.06);border-color:rgba(196,30,58,.25);transform:translateY(-4px)}
.community-card .emoji{font-size:2.5rem;margin-bottom:12px}
.community-card h4{color:var(--white);margin-bottom:8px;font-size:1.05rem}
.community-card p{color:var(--silver2);font-size:.85rem}
.community-card .count{color:var(--red);font-weight:700;font-size:1.1rem;margin-top:8px}

/* === 专家展示 === */
.expert-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:28px}
.expert-card{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius-lg);overflow:hidden;transition:all .4s}
.expert-card:hover{border-color:rgba(196,30,58,.3);transform:translateY(-6px);box-shadow:var(--shadow-hover)}
.expert-card .avatar{width:100%;aspect-ratio:1;overflow:hidden}
.expert-card .avatar img{width:100%;height:100%;object-fit:cover;transition:transform .5s}
.expert-card:hover .avatar img{transform:scale(1.05)}
.expert-card .info{padding:20px}
.expert-card .info h4{color:var(--white);font-size:1.1rem;margin-bottom:4px}
.expert-card .info .role{color:var(--red);font-size:.85rem;margin-bottom:10px}
.expert-card .info p{color:var(--silver2);font-size:.85rem;margin-bottom:14px;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.expert-card .info .btns{display:flex;gap:8px}

/* === 合作品牌 === */
.partner-wall{display:flex;flex-wrap:wrap;gap:20px;justify-content:center;align-items:center}
.partner-item{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.1);border-radius:var(--radius);padding:20px 32px;color:var(--silver2);font-size:1rem;font-weight:600;transition:all .3s;letter-spacing:1px}
.partner-item:hover{border-color:var(--red);color:var(--white);background:rgba(196,30,58,.1)}

/* === FAQ === */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);margin-bottom:12px;overflow:hidden;transition:all .3s}
.faq-item:hover{border-color:rgba(196,30,58,.25)}
.faq-item .faq-q{padding:18px 24px;color:var(--white);font-weight:600;cursor:pointer;display:flex;justify-content:space-between;align-items:center;background:rgba(255,255,255,.03);transition:all .3s}
.faq-item .faq-q:hover{background:rgba(196,30,58,.08)}
.faq-item .faq-q .arrow{transition:transform .3s;color:var(--red)}
.faq-item.open .faq-q .arrow{transform:rotate(180deg)}
.faq-item .faq-a{padding:0 24px;max-height:0;overflow:hidden;transition:all .4s;color:var(--silver2);font-size:.92rem;line-height:1.8}
.faq-item.open .faq-a{padding:16px 24px;max-height:500px}

/* === 用户评价 === */
.review-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px}
.review-card{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);padding:24px;transition:all .3s}
.review-card:hover{border-color:rgba(196,30,58,.25);transform:translateY(-3px)}
.review-card .stars{color:var(--gold);font-size:1.1rem;margin-bottom:12px;letter-spacing:2px}
.review-card .text{color:var(--silver);font-size:.92rem;margin-bottom:16px;line-height:1.7;font-style:italic}
.review-card .user{display:flex;align-items:center;gap:12px}
.review-card .user .avatar-sm{width:40px;height:40px;border-radius:50%;background:var(--gradient-red);display:flex;align-items:center;justify-content:center;color:var(--white);font-weight:700;font-size:.9rem}
.review-card .user .name{color:var(--white);font-weight:600;font-size:.9rem}
.review-card .user .date{color:var(--silver2);font-size:.75rem}

/* === 联系我们 === */
.contact-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:28px}
.contact-card{background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);padding:28px;text-align:center;transition:all .3s}
.contact-card:hover{border-color:rgba(196,30,58,.25)}
.contact-card .icon-wrap{width:52px;height:52px;background:var(--gradient-red);border-radius:50%;display:flex;align-items:center;justify-content:center;margin:0 auto 16px}
.contact-card h4{color:var(--white);margin-bottom:8px}
.contact-card p{color:var(--silver2);font-size:.9rem}

/* === How-To指南 === */
.howto-steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:24px;counter-reset:step}
.howto-step{background:rgba(255,255,255,.03);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);padding:28px;text-align:center;position:relative;counter-increment:step;transition:all .3s}
.howto-step:hover{border-color:rgba(196,30,58,.3);transform:translateY(-3px)}
.howto-step::before{content:counter(step);position:absolute;top:-16px;left:50%;transform:translateX(-50%);width:32px;height:32px;background:var(--gradient-red);border-radius:50%;display:flex;align-items:center;justify-content:center;color:var(--white);font-weight:700;font-size:.9rem;line-height:32px}
.howto-step h4{color:var(--white);margin:12px 0 8px;font-size:1rem}
.howto-step p{color:var(--silver2);font-size:.85rem}

/* === 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 20px;border-radius:24px;font-size:.85rem;font-weight:600;transition:all .3s;border:1px solid rgba(255,255,255,.1);color:var(--silver)}
.share-btn:hover{transform:translateY(-2px);border-color:var(--red);color:var(--white)}
.share-btn.wechat:hover{border-color:#07C160;color:#07C160}
.share-btn.weibo:hover{border-color:#E6162D;color:#E6162D}
.share-btn.douyin:hover{border-color:#FE2C55;color:#FE2C55}
.share-btn.bilibili:hover{border-color:#00A1D6;color:#00A1D6}

/* === 页脚 === */
.site-footer{background:#080812;border-top:1px solid rgba(255,255,255,.06);padding:60px 0 0}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:40px}
.footer-brand .logo-wrap{margin-bottom:16px}
.footer-brand p{color:var(--silver2);font-size:.88rem;line-height:1.7;margin-bottom:16px}
.footer-col h5{color:var(--white);font-size:1rem;margin-bottom:16px;position:relative;padding-bottom:10px}
.footer-col h5::after{content:'';position:absolute;bottom:0;left:0;width:30px;height:2px;background:var(--red)}
.footer-col a{display:block;color:var(--silver2);font-size:.88rem;padding:4px 0;transition:color .3s}
.footer-col a:hover{color:var(--red)}
.footer-qr{display:flex;gap:20px;margin-top:16px}
.footer-qr .qr-item{text-align:center}
.footer-qr .qr-item img{width:120px;height:120px;border-radius:8px;border:1px solid rgba(255,255,255,.1)}
.footer-qr .qr-item span{display:block;color:var(--silver2);font-size:.75rem;margin-top:6px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.06);padding:20px 0;text-align:center;color:var(--silver2);font-size:.82rem}
.footer-bottom a{color:var(--red)}

/* === 面包屑 === */
.breadcrumb{padding:16px 0;color:var(--silver2);font-size:.85rem}
.breadcrumb a{color:var(--silver2);transition:color .3s}
.breadcrumb a:hover{color:var(--red)}
.breadcrumb span{margin:0 8px;color:rgba(255,255,255,.3)}

/* === 内页通用 === */
.page-hero{padding:120px 0 60px;background:linear-gradient(180deg,var(--dark) 0%,#0D0D1A 100%);text-align:center}
.page-hero h1{font-size:2.4rem;color:var(--white);margin-bottom:12px}
.page-hero p{color:var(--silver2);font-size:1.05rem}

/* === 统计数字 === */
.stats-row{display:flex;justify-content:center;gap:48px;flex-wrap:wrap;padding:40px 0}
.stat-item{text-align:center}
.stat-item .num{font-size:2.5rem;font-weight:800;color:var(--red);display:block}
.stat-item .label{color:var(--silver2);font-size:.9rem;margin-top:4px}

/* === MCP前端代码区 === */
.mcp-widget{background:rgba(255,255,255,.03);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);padding:20px;margin:20px 0}
.mcp-widget pre{background:rgba(0,0,0,.3);border-radius:8px;padding:16px;color:#7FDB8A;font-size:.82rem;overflow-x:auto;font-family:'Courier New',monospace}

/* === 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:1024px){
  .footer-grid{grid-template-columns:1fr 1fr}
  .hero h1{font-size:2.4rem}
  .video-grid{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}
}
@media(max-width:768px){
  .main-nav{display:none;position:fixed;top:72px;left:0;width:100%;background:rgba(13,13,26,.98);flex-direction:column;padding:20px;gap:4px;border-bottom:1px solid rgba(196,30,58,.2)}
  .main-nav.open{display:flex}
  .mobile-toggle{display:flex}
  .hero h1{font-size:1.8rem}
  .hero .hero-sub{font-size:1rem}
  .section{padding:50px 0}
  .section-header h2{font-size:1.6rem}
  .footer-grid{grid-template-columns:1fr}
  .stats-row{gap:24px}
  .stat-item .num{font-size:1.8rem}
  .expert-grid{grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}
  .header-inner{padding:0 16px}
  .video-grid{grid-template-columns:1fr}
}
@media(max-width:480px){
  .hero{min-height:70vh}
  .hero h1{font-size:1.5rem}
  .btn{padding:12px 24px;font-size:.9rem}
  .hero-btns{flex-direction:column;align-items:center}
  .container{padding:0 16px}
}

/* === 动画 === */
@keyframes fadeInUp{from{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}
@keyframes pulse{0%,100%{transform:scale(1)}50%{transform:scale(1.05)}}
.animate-in{animation:fadeInUp .6s ease forwards;opacity:0}
.delay-1{animation-delay:.1s}
.delay-2{animation-delay:.2s}
.delay-3{animation-delay:.3s}
.delay-4{animation-delay:.4s}

/* === 懒加载占位 === */
.lazy{opacity:0;transition:opacity .5s}
.lazy.loaded{opacity:1}

/* === 回到顶部 === */
.back-to-top{position:fixed;bottom:30px;right:30px;width:48px;height:48px;background:var(--gradient-red);border-radius:50%;display:flex;align-items:center;justify-content:center;cursor:pointer;opacity:0;visibility:hidden;transition:all .3s;z-index:999;border:none;box-shadow:0 4px 16px rgba(196,30,58,.4)}
.back-to-top.visible{opacity:1;visibility:visible}
.back-to-top:hover{transform:translateY(-3px)}
.back-to-top svg{width:20px;height:20px;fill:var(--white)}