:root{
      /* 品牌色彩保持一致 */
      --brand-primary: #3b82f6;      /* 主蓝色 */
      --brand-secondary: #8b5cf6;    /* 辅助紫色 */
      --brand-gradient: linear-gradient(135deg, var(--brand-primary), var(--brand-secondary));
      --accent: #f97316;             /* 亮橙色用于突出按钮和交互元素 */
      --accent-hover: #ea580c;
      --ink: #0f172a;                 /* 深色文字 */
      --muted: #64748b;               /* 次级文字 */
      --light-muted: #94a3b8;         /* 更浅的文字 */
      --bg-dark: #0f172a;             /* 顶部/底部深色 */
      --bg-light: #f8fafc;            /* 浅色背景 */
      --card: #ffffff;                /* 白卡片 */
      --border: #e2e8f0;              /* 边框色 */
      --radius: 12px;
      --shadow: 0 10px 25px -5px rgba(59, 130, 246, 0.1), 0 8px 10px -6px rgba(59, 130, 246, 0.05);
      --shadow-hover: 0 20px 25px -5px rgba(59, 130, 246, 0.1), 0 10px 10px -5px rgba(59, 130, 246, 0.04);
      --maxw: 1200px;
      --transition: all 0.3s ease;
    }
    *{box-sizing:border-box}
    html,body{margin:0;height:100%;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,"Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC",sans-serif;color:var(--ink);background:var(--bg-light);scroll-behavior: smooth;}
    a{color:inherit;text-decoration:none}
    img{max-width:100%;display:block}
    .container{max-width:var(--maxw);margin:0 auto;padding:0 20px}

    /* 顶部导航 - 保持不变 */
    header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:saturate(180%) blur(12px);border-bottom:1px solid var(--border);transition: var(--transition);}
    header.scrolled {box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);}
    .nav{display:flex;align-items:center;justify-content:space-between;height:72px}
    .logo{display:flex;gap:10px;align-items:center;font-weight:800;letter-spacing:.3px;font-size:1.25rem;color:var(--brand-primary);}
    .logo .dot{width:12px;height:12px;background:var(--brand-gradient);border-radius:50%}
    nav ul{display:flex;gap:32px;list-style:none;margin:0;padding:0}
    nav a{font-size:15px;color:var(--ink);font-weight:500;position:relative;padding:5px 0;transition: var(--transition);}
    nav a:hover{color:var(--brand-primary);}
    nav a:after{content:'';position:absolute;bottom:0;left:0;width:0;height:2px;background:var(--brand-gradient);transition: var(--transition);}
    nav a:hover:after{width:100%;}
    .cta{display:inline-flex;align-items:center;gap:10px;background:var(--accent);color:#fff;padding:10px 20px;border-radius:999px;box-shadow:0 4px 6px -1px rgba(249, 115, 22, 0.2);font-weight:500;transition: var(--transition);}
    .cta:hover{transform:translateY(-2px);background:var(--accent-hover);box-shadow:0 10px 15px -3px rgba(249, 115, 22, 0.2);}

    /* SEO产品页面特有样式 */
    .seo-hero{
      background:var(--bg-dark);
      color:white;
      padding:80px 0 100px;
      position:relative;
      overflow:hidden;
    }
    .seo-hero:before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 30% 50%, rgba(59, 130, 246, 0.2) 0%, transparent 60%),
                  radial-gradient(circle at 70% 70%, rgba(139, 92, 246, 0.2) 0%, transparent 60%);
      z-index: 0;
    }
    .seo-hero-content{
      position:relative;
      z-index:1;
      max-width:800px;
      margin:0 auto;
      text-align:center;
    }
    .seo-hero h1{
      font-size:clamp(2.2rem, 5vw, 3.8rem);
      line-height:1.15;
      margin:0 0 20px;
    }
    .seo-hero h1 span{
      background:var(--brand-gradient);
      -webkit-background-clip:text;
      background-clip:text;
      color:transparent;
    }
    .seo-hero p{
      color:#cbd5e1;
      font-size:1.1rem;
      margin:0 0 36px;
      line-height:1.7;
    }
    .seo-hero .stats{
      display:flex;
      justify-content:center;
      gap:40px;
      margin:40px 0 0;
      flex-wrap:wrap;
    }
    .stat-item{
      text-align:center;
    }
    .stat-number{
      font-size:2.5rem;
      font-weight:bold;
      margin:0 0 8px;
      background:var(--brand-gradient);
      -webkit-background-clip:text;
      background-clip:text;
      color:transparent;
    }
    .stat-label{
      color:#cbd5e1;
      font-size:1rem;
      margin:0;
    }
    .seo-hero .actions{
      display:flex;
      gap:16px;
      flex-wrap:wrap;
      justify-content:center;
    }
    .btn{
      display:inline-flex;
      align-items:center;
      gap:8px;
      padding:14px 24px;
      border-radius:12px;
      border:1px solid transparent;
      font-weight:500;
      transition: var(--transition);
      font-size:16px;
    }
    .btn.primary{
      background:var(--accent);
      color:#fff;
    }
    .btn.primary:hover{
      background:var(--accent-hover);
      transform: translateY(-2px);
      box-shadow:0 10px 15px -3px rgba(249, 115, 22, 0.2);
    }
    .btn.secondary{
      background:rgba(255,255,255,0.1);
      color:white;
      border-color:rgba(255,255,255,0.2);
    }
    .btn.secondary:hover{
      background:rgba(255,255,255,0.15);
      transform: translateY(-2px);
    }

    /* SEO服务内容 */
    .seo-services{
      padding:100px 0;
      background:var(--card);
    }
    .section-head{
      max-width:700px;
      margin:0 auto 60px;
      text-align:center;
    }
    .section-head h2{
      margin:0 0 16px;
      font-size:clamp(1.75rem, 4vw, 2.5rem);
      position:relative;
      display:inline-block;
    }
    .section-head h2:after{
      content:'';
      position:absolute;
      bottom:-8px;
      left:50%;
      transform:translateX(-50%);
      width:60px;
      height:4px;
      background:var(--brand-gradient);
      border-radius:2px;
    }
    .section-desc{
      color:var(--muted);
      font-size:16px;
      line-height:1.6;
      max-width:600px;
      margin:0 auto;
    }
    .services-grid{
      display:grid;
      grid-template-columns:repeat(auto-fit, minmax(300px, 1fr));
      gap:30px;
      margin-top:40px;
    }
    .service-card{
      background:var(--bg-light);
      border-radius:var(--radius);
      padding:36px;
      box-shadow:var(--shadow);
      transition: var(--transition);
      display:flex;
      flex-direction:column;
      height:100%;
    }
    .service-card:hover{
      transform: translateY(-8px);
      box-shadow:var(--shadow-hover);
    }
    .service-icon{
      width:70px;
      height:70px;
      border-radius:16px;
      background:var(--brand-gradient);
      display:flex;
      align-items:center;
      justify-content:center;
      color:white;
      font-size:28px;
      margin-bottom:24px;
    }
    .service-card h3{
      margin:0 0 16px;
      font-size:22px;
    }
    .service-card p{
      margin:0 0 20px;
      color:var(--muted);
      font-size:16px;
      line-height:1.7;
      flex-grow:1;
    }
    .service-list{
      padding-left:0;
      margin:0 0 24px;
      list-style:none;
    }
    .service-list li{
      display:flex;
      align-items:start;
      gap:10px;
      margin-bottom:12px;
      color:var(--ink);
    }
    .service-list li i{
      color:var(--brand-primary);
      margin-top:4px;
    }

    /* 搜索引擎专项优化方案 */
    .search-engine-optimization {
      padding: 100px 0;
      background: var(--bg-light);
    }
    .engine-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 30px;
      margin-top: 40px;
    }
    .engine-card {
      background: var(--card);
      border-radius: var(--radius);
      padding: 36px;
      box-shadow: var(--shadow);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      height: 100%;
      border-top: 5px solid;
    }
    .engine-card.baidu {
      border-top-color: #2319dc;
    }
    .engine-card.google {
      border-top-color: #4285F4;
    }
    .engine-card.bing {
      border-top-color: #0066B2;
    }
    .engine-card.sogou {
      border-top-color: #E6162D;
    }
    .engine-card.so {
      border-top-color: #F53F3F;
    }
    .engine-card.yandex {
      border-top-color: #FF0000;
    }
    .engine-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }
    .engine-header {
      display: flex;
      align-items: center;
      gap: 15px;
      margin-bottom: 24px;
    }
    .engine-logo {
      width: 60px;
      height: 60px;
      border-radius: 12px;
      background-color: rgba(0,0,0,0.05);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 28px;
      color: inherit;
    }
    .engine-card h3 {
      margin: 0;
      font-size: 22px;
    }
    .engine-meta {
      font-size: 14px;
      color: var(--muted);
      margin-bottom: 20px;
      padding-bottom: 15px;
      border-bottom: 1px dashed var(--border);
    }
    .engine-card p {
      margin: 0 0 20px;
      color: var(--muted);
      font-size: 16px;
      line-height: 1.7;
    }
    .engine-features {
      padding-left: 0;
      margin: 0 0 24px;
      list-style: none;
      flex-grow: 1;
    }
    .engine-features li {
      display: flex;
      align-items: start;
      gap: 10px;
      margin-bottom: 12px;
      color: var(--ink);
    }
    .engine-features li:last-child {
      margin-bottom: 0;
    }
    .engine-features li i {
      color: var(--brand-primary);
      margin-top: 4px;
    }

    /* SEO方案类型 */
    .seo-plans{
      padding:100px 0;
      background:var(--bg-light);
    }
    .plans-grid{
      display:grid;
      grid-template-columns:repeat(auto-fit, minmax(340px, 1fr));
      gap:36px;
      margin-top:40px;
    }
    .plan-card{
      background:var(--card);
      border-radius:var(--radius);
      overflow:hidden;
      box-shadow:var(--shadow);
      transition: var(--transition);
      display:flex;
      flex-direction:column;
      height:100%;
      position:relative;
    }
    .plan-card.popular{
      transform: scale(1.03);
    }
    .plan-card.popular:before{
      content:'最受欢迎';
      position:absolute;
      top:0;
      left:0;
      right:0;
      background:var(--accent);
      color:white;
      text-align:center;
      padding:5px 0;
      font-weight:500;
      font-size:14px;
    }
    .plan-card:hover{
      transform: translateY(-8px);
      box-shadow:var(--shadow-hover);
    }
    .plan-header{
      padding:30px;
      background:var(--bg-dark);
      color:white;
      text-align:center;
    }
    .plan-header h3{
      margin:0 0 10px;
      font-size:24px;
    }
    .plan-price{
      font-size:40px;
      font-weight:bold;
      margin:0 0 5px;
    }
    .plan-period{
      color:#cbd5e1;
      font-size:14px;
      margin:0 0 15px;
    }
    .plan-features{
      padding:30px;
      flex-grow:1;
    }
    .plan-feature{
      display:flex;
      align-items:center;
      gap:10px;
      margin-bottom:15px;
      color:var(--ink);
      font-size:15px;
    }
    .plan-feature i{
      color:var(--brand-primary);
    }
    .plan-feature.disabled{
      color:var(--light-muted);
    }
    .plan-feature.disabled i{
      color:var(--light-muted);
    }
    .search-engine-heading {
      font-size: 16px;
      font-weight: 600;
      margin: 25px 0 15px;
      color: var(--brand-primary);
      padding-top: 15px;
      border-top: 1px dashed var(--border);
    }
    .plan-cta{
      padding:0 30px 30px;
    }
    .plan-cta .btn{
      width:100%;
      justify-content:center;
    }

    /* SEO优化流程 */
    .seo-process{
      padding:100px 0;
      background:var(--card);
    }
    .process-steps{
      display:flex;
      flex-wrap:wrap;
      justify-content:center;
      position:relative;
      margin-top:60px;
    }
    /* 连接线 */
    .process-steps:before{
      content:'';
      position:absolute;
      top:50px;
      left:10%;
      right:10%;
      height:4px;
      background:var(--brand-gradient);
      z-index:1;
    }
    .step{
      flex:1;
      min-width:200px;
      max-width:240px;
      padding:0 20px;
      position:relative;
      z-index:2;
      text-align:center;
      margin-bottom:30px;
    }
    .step-number{
      width:100px;
      height:100px;
      border-radius:50%;
      background:var(--brand-gradient);
      color:white;
      font-size:32px;
      font-weight:bold;
      display:flex;
      align-items:center;
      justify-content:center;
      margin:0 auto 20px;
      box-shadow:var(--shadow);
      transition: var(--transition);
    }
    .step:hover .step-number{
      transform: scale(1.1);
    }
    .step h3{
      margin:0 0 12px;
      font-size:18px;
    }
    .step p{
      margin:0;
      color:var(--muted);
      font-size:14px;
      line-height:1.6;
    }

    /* SEO成功案例 */
    .seo-case-studies{
      padding:100px 0;
      background:var(--bg-light);
    }
    .cases-grid{
      display:grid;
      grid-template-columns:repeat(auto-fit, minmax(340px, 1fr));
      gap:36px;
      margin-top:40px;
    }
    .case-card{
      background:var(--card);
      border-radius:var(--radius);
      overflow:hidden;
      box-shadow:var(--shadow);
      transition: var(--transition);
      display:flex;
      flex-direction:column;
      height:100%;
    }
    .case-card:hover{
      transform: translateY(-8px);
      box-shadow:var(--shadow-hover);
    }
    .case-image{
      height:200px;
      overflow:hidden;
      position:relative;
    }
    .case-image img{
      width:100%;
      height:100%;
      object-fit:cover;
      transition: transform 0.6s ease;
    }
    .case-card:hover .case-image img{
      transform: scale(1.05);
    }
    .case-content{
      padding:30px;
      flex-grow:1;
      display:flex;
      flex-direction:column;
    }
    .case-meta{
      display:flex;
      gap:15px;
      margin:0 0 15px;
      font-size:14px;
      color:var(--muted);
    }
    .case-meta span{
      display:flex;
      align-items:center;
      gap:5px;
    }
    .case-card h3{
      margin:0 0 16px;
      font-size:22px;
    }
    .case-card p{
      margin:0 0 20px;
      color:var(--muted);
      font-size:16px;
      line-height:1.6;
      flex-grow:1;
    }
    .case-results{
      background:var(--bg-light);
      border-radius:8px;
      padding:15px;
      margin:0 0 20px;
    }
    .case-result-item{
      display:flex;
      justify-content:space-between;
      margin-bottom:10px;
      font-size:15px;
    }
    .case-result-item:last-child{
      margin-bottom:0;
    }
    .case-result-label{
      color:var(--ink);
    }
    .case-result-value{
      font-weight:500;
      color:var(--accent);
    }

    /* 为什么选择我们 */
    .why-choose-us{
      padding:100px 0;
      background:var(--card);
    }
    .choose-grid{
      display:grid;
      grid-template-columns:repeat(auto-fit, minmax(250px, 1fr));
      gap:24px;
      margin-top:40px;
    }
    .choose-item{
      background:var(--bg-light);
      border-radius:var(--radius);
      padding:28px;
      box-shadow:var(--shadow);
      transition: var(--transition);
      text-align:center;
    }
    .choose-item:hover{
      transform: translateY(-5px);
      box-shadow:var(--shadow-hover);
    }
    .choose-icon{
      width:60px;
      height:60px;
      border-radius:12px;
      background:var(--brand-gradient);
      display:flex;
      align-items:center;
      justify-content:center;
      color:white;
      font-size:24px;
      margin:0 auto 20px;
    }
    .choose-item h3{
      margin:0 0 12px;
      font-size:18px;
    }
    .choose-item p{
      margin:0;
      color:var(--muted);
      font-size:15px;
      line-height:1.6;
    }

    /* 常见问题 */
    .faq-section{
      padding:100px 0;
      background:var(--bg-light);
    }
    .faq-container{
      max-width:800px;
      margin:40px auto 0;
    }
    .faq-item{
      margin-bottom:16px;
      border-radius:var(--radius);
      overflow:hidden;
      box-shadow:var(--shadow);
    }
    .faq-question{
      background:var(--card);
      padding:20px 24px;
      width:100%;
      border:none;
      text-align:left;
      font-size:18px;
      font-weight:500;
      display:flex;
      justify-content:space-between;
      align-items:center;
      cursor:pointer;
      transition: var(--transition);
    }
    .faq-question:hover{
      background:var(--bg-light);
    }
    .faq-question i{
      color:var(--brand-primary);
      transition: transform 0.3s ease;
    }
    .faq-answer{
      background:var(--card);
      padding:0 24px;
      max-height:0;
      overflow:hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
    }
    .faq-answer p{
      margin:0;
      color:var(--muted);
      line-height:1.7;
    }
    .faq-item.active .faq-answer{
      padding:0 24px 24px;
      max-height:500px;
    }
    .faq-item.active .faq-question i{
      transform: rotate(180deg);
    }

    /* 底部 - 保持不变 */
    footer{background:var(--bg-dark);color:#e2e8f0;padding:80px 0 40px;position:relative;}
    footer:before{
      content:'';
      position:absolute;
      top:0;
      left:0;
      width:100%;
      height:8px;
      background:var(--brand-gradient);
    }
    .foot{display:grid;grid-template-columns:1.5fr 1fr 1fr;gap:40px;}
    .foot-col h4{margin:0 0 20px;font-size:18px;color:white;position:relative;display:inline-block;}
    .foot-col h4:after{
      content:'';
      position:absolute;
      bottom:-6px;
      left:0;
      width:30px;
      height:2px;
      background:var(--accent);
    }
    .foot-col p{margin:0 0 16px;line-height:1.7;color:#94a3b8;}
    .contact-info{display:flex;align-items:center;gap:12px;margin-bottom:16px;color:#94a3b8;}
    .contact-info i{color:var(--accent);width:20px;text-align:center;}
    .social-links{display:flex;gap:12px;margin-top:20px;}
    .social-links a{width:36px;height:36px;border-radius:50%;background:rgba(255,255,255,0.1);display:flex;align-items:center;justify-content:center;color:white;transition: var(--transition);}
    .social-links a:hover{background:var(--accent);transform: translateY(-3px);}
    .foot-nav{display:flex;flex-wrap:wrap;gap:10px 20px;}
    .foot-nav a{color:#94a3b8;transition: var(--transition);}
    .foot-nav a:hover{color:white;}
    .copyright{margin-top:40px;border-top:1px solid rgba(255,255,255,.1);padding-top:24px;color:#94a3b8;font-size:14px;text-align:center;}

    /* 响应式调整 */
    @media (max-width: 1100px){
      .services-grid, .engine-grid, .plans-grid, .cases-grid, .choose-grid{
        grid-template-columns:repeat(2, 1fr);
      }
      .process-steps:before{
        left:5%;
        right:5%;
      }
    }
    @media (max-width: 768px){
      nav ul{display:none}
      .services-grid, .engine-grid, .plans-grid, .cases-grid, .choose-grid{
        grid-template-columns:1fr;
      }
      .step{
        min-width:100%;
        max-width:none;
      }
      .process-steps:before{
        display:none;
      }
      .seo-hero, .seo-services, .search-engine-optimization, .seo-plans, .seo-process, .seo-case-studies, .why-choose-us, .faq-section{
        padding:60px 0;
      }
      .plan-card.popular{
        transform: none;
      }
    }
    @media (max-width: 480px){
      .btn{
        padding:12px 20px;
        font-size:14px;
        width:100%;
        justify-content:center;
      }
      .seo-hero h1{
        font-size:2rem;
      }
      .seo-hero .stats{
        gap:20px;
      }
      .stat-number{
        font-size:2rem;
      }
    }