/* ============================================
   困困兔 - 汽车改装视频社区 原创样式
   域名: ddwhk.cn
   配色: 深碳灰 #0F1117 / 赛车红 #C41E3A / 银灰 #E8E9ED / 金属蓝 #2A6FDB
   ============================================ */

/* === 基础重置 === */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{font-size:16px;scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","WenQuanYi Micro Hei",sans-serif;background:#0F1117;color:#E8E9ED;line-height:1.7;overflow-x:hidden}
a{color:#E8E9ED;text-decoration:none;transition:color .25s}
a:hover{color:#C41E3A}
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}

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

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

/* === 顶部导航 === */
.kkt-header{position:fixed;top:0;left:0;width:100%;z-index:1000;background:rgba(15,17,23,.95);backdrop-filter:blur(12px);border-bottom:1px solid rgba(196,30,58,.3);transition:all .3s}
.kkt-header-inner{display:flex;align-items:center;justify-content:space-between;height:68px;max-width:1280px;margin:0 auto;padding:0 20px}
.kkt-logo{display:flex;align-items:center;gap:10px}
.kkt-logo img{height:42px;width:auto}
.kkt-logo-text{font-size:1.25rem;font-weight:800;color:#C41E3A;letter-spacing:1px}
.kkt-nav{display:flex;align-items:center;gap:6px}
.kkt-nav a{padding:8px 14px;border-radius:6px;font-size:.9rem;font-weight:500;transition:all .25s;color:#b0b3be}
.kkt-nav a:hover,.kkt-nav a.active{color:#fff;background:rgba(196,30,58,.15)}

/* === 搜索框 === */
.kkt-search-bar{background:rgba(15,17,23,.8);padding:12px 0;border-bottom:1px solid rgba(255,255,255,.06);margin-top:68px}
.kkt-search-wrap{display:flex;align-items:center;max-width:640px;margin:0 auto;background:#1A1C25;border:1px solid rgba(196,30,58,.25);border-radius:30px;overflow:hidden;padding:4px}
.kkt-search-wrap input{flex:1;background:transparent;border:none;outline:none;color:#E8E9ED;padding:8px 18px;font-size:.95rem}
.kkt-search-wrap input::placeholder{color:#666}
.kkt-search-wrap button{background:#C41E3A;color:#fff;border:none;padding:8px 22px;border-radius:26px;cursor:pointer;font-size:.9rem;font-weight:600;transition:background .25s}
.kkt-search-wrap button:hover{background:#a01830}

/* === Banner 英雄区 === */
.kkt-hero{position:relative;height:520px;overflow:hidden;margin-top:0}
.kkt-hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;filter:brightness(.55)}
.kkt-hero-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(15,17,23,.3) 0%,rgba(15,17,23,.85) 100%)}
.kkt-hero-content{position:relative;z-index:2;display:flex;flex-direction:column;justify-content:center;align-items:center;height:100%;text-align:center;padding:0 20px}
.kkt-hero h1{font-size:2.8rem;margin-bottom:12px;text-shadow:0 2px 20px rgba(0,0,0,.6)}
.kkt-hero h1 span{color:#C41E3A}
.kkt-hero .subtitle{font-size:1.15rem;color:#aaa;max-width:680px;margin-bottom:24px}
.kkt-hero .hero-tags{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}
.kkt-hero .hero-tags span{background:rgba(196,30,58,.2);border:1px solid rgba(196,30,58,.4);padding:5px 16px;border-radius:20px;font-size:.85rem;color:#E8E9ED}

/* === 区块通用 === */
.kkt-section{padding:60px 0}
.kkt-section-title{text-align:center;margin-bottom:40px}
.kkt-section-title h2{font-size:1.9rem;margin-bottom:8px}
.kkt-section-title h2 span{color:#C41E3A}
.kkt-section-title p{color:#888;font-size:.95rem}
.kkt-section-alt{background:#13151D}

/* === 视频卡片网格 === */
.kkt-video-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.kkt-video-card{position:relative;border-radius:12px;overflow:hidden;background:#1A1C25;transition:transform .3s,box-shadow .3s;cursor:pointer}
.kkt-video-card:hover{transform:translateY(-6px);box-shadow:0 12px 36px rgba(196,30,58,.15)}
.kkt-video-thumb{position:relative;aspect-ratio:16/9;overflow:hidden}
.kkt-video-thumb img{width:100%;height:100%;object-fit:cover;transition:transform .4s}
.kkt-video-card:hover .kkt-video-thumb img{transform:scale(1.06)}
.kkt-play-btn{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .3s;background:rgba(0,0,0,.35)}
.kkt-video-card:hover .kkt-play-btn{opacity:1}
.kkt-play-btn svg{width:56px;height:56px;fill:#fff;filter:drop-shadow(0 2px 8px rgba(0,0,0,.5))}
.kkt-video-info{padding:14px 16px}
.kkt-video-info h3{font-size:1rem;margin-bottom:6px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.kkt-video-meta{display:flex;gap:14px;color:#777;font-size:.8rem}
.kkt-video-meta span{display:flex;align-items:center;gap:4px}
.kkt-video-tag{position:absolute;top:10px;left:10px;background:rgba(196,30,58,.9);color:#fff;padding:2px 10px;border-radius:4px;font-size:.75rem;font-weight:600;z-index:2}
.kkt-video-duration{position:absolute;bottom:10px;right:10px;background:rgba(0,0,0,.75);color:#fff;padding:2px 8px;border-radius:4px;font-size:.75rem;z-index:2}

/* === 分类标签栏 === */
.kkt-tabs{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-bottom:30px}
.kkt-tabs a{padding:7px 20px;border-radius:20px;font-size:.88rem;background:#1A1C25;border:1px solid rgba(255,255,255,.08);transition:all .25s}
.kkt-tabs a:hover,.kkt-tabs a.active{background:#C41E3A;border-color:#C41E3A;color:#fff}

/* === 专家卡片 === */
.kkt-expert-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.kkt-expert-card{background:#1A1C25;border-radius:14px;padding:28px;text-align:center;border:1px solid rgba(255,255,255,.06);transition:all .3s}
.kkt-expert-card:hover{border-color:rgba(196,30,58,.4);box-shadow:0 8px 30px rgba(196,30,58,.1)}
.kkt-expert-card img{width:100px;height:100px;border-radius:50%;object-fit:cover;margin:0 auto 16px;border:3px solid #C41E3A}
.kkt-expert-card h4{font-size:1.1rem;margin-bottom:4px}
.kkt-expert-card .role{color:#C41E3A;font-size:.85rem;margin-bottom:10px}
.kkt-expert-card p{color:#888;font-size:.85rem;margin-bottom:14px}
.kkt-expert-btns{display:flex;gap:10px;justify-content:center}
.kkt-expert-btns a{padding:6px 16px;border-radius:6px;font-size:.82rem;border:1px solid rgba(196,30,58,.5);transition:all .25s}
.kkt-expert-btns a:hover{background:#C41E3A;border-color:#C41E3A;color:#fff}

/* === AI赋能区块 === */
.kkt-ai-section{background:linear-gradient(135deg,#0F1117 0%,#141828 50%,#0F1117 100%)}
.kkt-ai-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.kkt-ai-card{background:rgba(42,111,219,.08);border:1px solid rgba(42,111,219,.2);border-radius:14px;padding:28px;text-align:center;transition:all .3s}
.kkt-ai-card:hover{border-color:rgba(42,111,219,.5);transform:translateY(-4px)}
.kkt-ai-card .ai-icon{font-size:2.5rem;margin-bottom:14px}
.kkt-ai-card h4{font-size:1.05rem;margin-bottom:8px;color:#6BAAFF}
.kkt-ai-card p{color:#888;font-size:.88rem}

/* === FAQ === */
.kkt-faq-list{max-width:800px;margin:0 auto}
.kkt-faq-item{background:#1A1C25;border-radius:10px;margin-bottom:12px;overflow:hidden;border:1px solid rgba(255,255,255,.06)}
.kkt-faq-q{padding:16px 20px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:.95rem;transition:background .25s}
.kkt-faq-q:hover{background:rgba(196,30,58,.08)}
.kkt-faq-q::after{content:"+";font-size:1.3rem;color:#C41E3A;transition:transform .3s}
.kkt-faq-item.open .kkt-faq-q::after{transform:rotate(45deg)}
.kkt-faq-a{max-height:0;overflow:hidden;transition:max-height .4s ease;padding:0 20px}
.kkt-faq-item.open .kkt-faq-a{max-height:300px;padding:0 20px 16px}
.kkt-faq-a p{color:#999;font-size:.9rem;line-height:1.7}

/* === 用户评论 === */
.kkt-review-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:24px}
.kkt-review-card{background:#1A1C25;border-radius:12px;padding:24px;border:1px solid rgba(255,255,255,.06)}
.kkt-review-header{display:flex;align-items:center;gap:12px;margin-bottom:12px}
.kkt-review-avatar{width:44px;height:44px;border-radius:50%;background:#C41E3A;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:1.1rem;color:#fff;flex-shrink:0}
.kkt-review-name{font-weight:600;font-size:.95rem}
.kkt-review-date{color:#666;font-size:.78rem}
.kkt-review-stars{color:#FFB800;margin-bottom:8px;font-size:.9rem;letter-spacing:2px}
.kkt-review-text{color:#aaa;font-size:.9rem;line-height:1.7}

/* === 合作品牌墙 === */
.kkt-brand-wall{display:flex;flex-wrap:wrap;gap:20px;justify-content:center;align-items:center}
.kkt-brand-item{background:#1A1C25;border-radius:10px;padding:16px 28px;border:1px solid rgba(255,255,255,.06);font-size:.95rem;font-weight:600;color:#888;transition:all .25s}
.kkt-brand-item:hover{border-color:#C41E3A;color:#E8E9ED}

/* === How-To指南 === */
.kkt-howto-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:30px}
.kkt-howto-step{text-align:center;padding:24px 16px;background:#1A1C25;border-radius:12px;border:1px solid rgba(255,255,255,.06)}
.kkt-howto-step .step-num{display:inline-flex;align-items:center;justify-content:center;width:40px;height:40px;border-radius:50%;background:#C41E3A;color:#fff;font-weight:700;font-size:1.1rem;margin-bottom:12px}
.kkt-howto-step h4{font-size:.95rem;margin-bottom:6px}
.kkt-howto-step p{color:#888;font-size:.82rem}

/* === 联系我们 === */
.kkt-contact-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:30px}
.kkt-contact-info{background:#1A1C25;border-radius:14px;padding:30px;border:1px solid rgba(255,255,255,.06)}
.kkt-contact-info h3{font-size:1.2rem;margin-bottom:18px;color:#C41E3A}
.kkt-contact-row{display:flex;align-items:flex-start;gap:12px;margin-bottom:14px;color:#aaa;font-size:.9rem}
.kkt-contact-row strong{color:#E8E9ED;min-width:80px}
.kkt-qrcode-wrap{display:flex;gap:30px;justify-content:center;margin-top:20px}
.kkt-qrcode-wrap figure{text-align:center}
.kkt-qrcode-wrap img{width:140px;height:140px;border-radius:8px}
.kkt-qrcode-wrap figcaption{margin-top:8px;color:#888;font-size:.82rem}

/* === 社交分享 === */
.kkt-share-bar{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-top:20px}
.kkt-share-bar a{display:inline-flex;align-items:center;gap:6px;padding:8px 18px;border-radius:8px;font-size:.85rem;font-weight:500;background:#1A1C25;border:1px solid rgba(255,255,255,.08);transition:all .25s}
.kkt-share-bar a:hover{border-color:#C41E3A;background:rgba(196,30,58,.1)}

/* === 页脚 === */
.kkt-footer{background:#0A0B10;border-top:1px solid rgba(196,30,58,.2);padding:40px 0 20px}
.kkt-footer-inner{display:grid;grid-template-columns:1fr 1fr 1fr;gap:30px;margin-bottom:30px}
.kkt-footer-col h4{font-size:1rem;margin-bottom:14px;color:#C41E3A}
.kkt-footer-col p,.kkt-footer-col a{color:#777;font-size:.85rem;line-height:2}
.kkt-footer-col a:hover{color:#C41E3A}
.kkt-footer-bottom{text-align:center;padding-top:20px;border-top:1px solid rgba(255,255,255,.06);color:#555;font-size:.82rem}

/* === 面包屑 === */
.kkt-breadcrumb{padding:14px 0;font-size:.85rem;color:#666}
.kkt-breadcrumb a{color:#888}
.kkt-breadcrumb a:hover{color:#C41E3A}
.kkt-breadcrumb span{margin:0 8px;color:#444}

/* === 内页通用 === */
.kkt-page-hero{padding:100px 0 40px;text-align:center;background:linear-gradient(180deg,rgba(196,30,58,.08) 0%,transparent 100%)}
.kkt-page-hero h1{font-size:2.2rem;margin-bottom:8px}
.kkt-page-hero p{color:#888;font-size:.95rem}

/* === 按钮 === */
.kkt-btn{display:inline-flex;align-items:center;gap:6px;padding:10px 24px;border-radius:8px;font-size:.9rem;font-weight:600;transition:all .25s;cursor:pointer;border:none}
.kkt-btn-primary{background:#C41E3A;color:#fff}
.kkt-btn-primary:hover{background:#a01830;color:#fff}
.kkt-btn-outline{background:transparent;border:1px solid #C41E3A;color:#C41E3A}
.kkt-btn-outline:hover{background:#C41E3A;color:#fff}

/* === 响应式 === */
@media(max-width:1024px){
  .kkt-video-grid,.kkt-expert-grid,.kkt-ai-grid{grid-template-columns:repeat(2,1fr)}
  .kkt-howto-steps{grid-template-columns:repeat(2,1fr)}
  .kkt-footer-inner{grid-template-columns:1fr 1fr}
}
@media(max-width:768px){
  .kkt-header-inner{height:56px}
  .kkt-nav{display:none}
  .kkt-mobile-toggle{display:block;cursor:pointer;font-size:1.5rem;color:#E8E9ED}
  .kkt-nav.open{display:flex;flex-direction:column;position:fixed;top:56px;left:0;right:0;background:#0F1117;padding:20px;gap:4px;border-bottom:1px solid rgba(196,30,58,.3)}
  .kkt-hero{height:380px}
  .kkt-hero h1{font-size:1.8rem}
  .kkt-video-grid,.kkt-expert-grid,.kkt-ai-grid,.kkt-review-grid{grid-template-columns:1fr}
  .kkt-contact-grid{grid-template-columns:1fr}
  .kkt-howto-steps{grid-template-columns:1fr}
  .kkt-footer-inner{grid-template-columns:1fr}
  .kkt-search-bar{margin-top:56px}
  .kkt-section{padding:40px 0}
  .kkt-section-title h2{font-size:1.5rem}
}
@media(max-width:480px){
  .kkt-hero{height:300px}
  .kkt-hero h1{font-size:1.4rem}
  .kkt-qrcode-wrap{flex-direction:column;align-items:center}
}

/* === 懒加载 === */
img[data-src]{opacity:1;transition:opacity .4s}
img.loaded{opacity:1}

/* === 滚动动画 === */
.kkt-fade-in{opacity:1;transform:translateY(0);transition:opacity .6s,transform .6s}
.kkt-fade-in.visible{opacity:1;transform:translateY(0)}

/* === 移动端菜单按钮 === */
.kkt-mobile-toggle{display:none;background:none;border:none;color:#E8E9ED;font-size:1.5rem;cursor:pointer}