/* roulang page: index */
/* ----- 设计变量 & 基础重置 ----- */
    :root {
      --deep-blue: #0A1F3F;
      --cyan: #00C2FF;
      --purple: #7B2FBE;
      --gold: #FF8C00;
      --bg-light: #F4F7FC;
      --white: #FFFFFF;
      --text-dark: #1E293B;
      --text-body: #333333;
      --text-muted: #555555;
      --border-light: #E0E6ED;
      --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 12px 32px rgba(0, 194, 255, 0.12);
      --radius-card: 18px;
      --radius-btn: 40px;
      --radius-input: 16px;
      --transition: 0.3s ease;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-stack);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.6;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: all var(--transition);
    }
    
    input, textarea {
      font-family: inherit;
      outline: none;
    }
    
    /* 容器 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 32px;
      width: 100%;
    }
    
    /* 区块间距 */
    section {
      padding: 90px 0;
    }
    
    @media (max-width: 768px) {
      .container {
        padding: 0 24px;
      }
      section {
        padding: 60px 0;
      }
    }
    
    /* ----- 导航栏 (悬浮胶囊) ----- */
    .navbar {
      position: fixed;
      top: 18px;
      left: 50%;
      transform: translateX(-50%);
      width: calc(100% - 48px);
      max-width: 1100px;
      background: rgba(255, 255, 255, 0.88);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-radius: 50px;
      padding: 10px 32px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      box-shadow: 0 10px 28px rgba(0, 0, 0, 0.08);
      z-index: 1000;
      border: 1px solid rgba(255,255,255,0.5);
    }
    
    .logo {
      font-size: 26px;
      font-weight: 700;
      color: var(--deep-blue);
      letter-spacing: 1px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--cyan);
      text-shadow: 0 0 8px rgba(0,194,255,0.3);
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-dark);
      padding: 6px 0;
      position: relative;
    }
    
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--cyan);
      transition: width 0.3s;
    }
    
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--cyan);
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    
    .nav-cta {
      background: var(--cyan);
      color: white;
      padding: 10px 24px;
      border-radius: 30px;
      font-weight: 600;
      font-size: 14px;
      box-shadow: 0 4px 12px rgba(0,194,255,0.3);
    }
    .nav-cta:hover {
      background: #0099CC;
      box-shadow: 0 8px 18px rgba(0,194,255,0.4);
      color: white;
    }
    
    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--deep-blue);
      background: transparent;
      border: none;
    }
    
    @media (max-width: 768px) {
      .navbar {
        padding: 10px 24px;
      }
      .nav-menu {
        display: none;
        position: absolute;
        top: 70px;
        left: 16px;
        right: 16px;
        background: var(--deep-blue);
        flex-direction: column;
        border-radius: 24px;
        padding: 28px;
        gap: 20px;
        box-shadow: 0 20px 40px rgba(0,0,0,0.3);
        backdrop-filter: blur(20px);
      }
      .nav-menu.active {
        display: flex;
      }
      .nav-menu a {
        color: white;
        font-size: 17px;
      }
      .hamburger {
        display: block;
      }
      .nav-cta {
        display: none;
      }
      .mobile-cta {
        display: block;
        background: var(--cyan);
        text-align: center;
        padding: 12px;
        border-radius: 30px;
        color: white;
        font-weight: 600;
        margin-top: 10px;
      }
    }
    
    /* ----- Hero 首屏 ----- */
    .hero {
      background: linear-gradient(135deg, #0A1F3F 0%, #0D2B4E 100%);
      color: white;
      padding: 160px 0 120px;
      position: relative;
      overflow: hidden;
    }
    
    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    
    .hero-text {
      flex: 1;
    }
    
    .hero h1 {
      font-size: 52px;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero h1 span {
      color: var(--cyan);
      border-bottom: 4px solid var(--cyan);
    }
    
    .hero-sub {
      font-size: 19px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 36px;
      max-width: 550px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    
    .btn-primary {
      background: var(--cyan);
      color: white;
      padding: 14px 34px;
      border-radius: 50px;
      font-weight: 600;
      font-size: 16px;
      box-shadow: 0 8px 20px rgba(0,194,255,0.4);
    }
    .btn-primary:hover {
      background: #0099CC;
      transform: translateY(-2px);
      box-shadow: 0 14px 28px rgba(0,194,255,0.5);
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--cyan);
      color: var(--cyan);
      padding: 14px 34px;
      border-radius: 50px;
      font-weight: 600;
      font-size: 16px;
    }
    .btn-outline:hover {
      background: var(--cyan);
      color: white;
    }
    
    .hero-image {
      flex: 1;
      border-radius: 28px;
      overflow: hidden;
      box-shadow: 0 30px 50px rgba(0,0,0,0.5);
      border: 2px solid rgba(255,255,255,0.15);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    
    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero h1 {
        font-size: 36px;
      }
      .hero-sub {
        font-size: 17px;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    
    /* 通用标题 */
    .section-title {
      font-size: 38px;
      font-weight: 700;
      color: var(--deep-blue);
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 4px;
      background: var(--cyan);
      margin-top: 10px;
      border-radius: 4px;
    }
    .text-center {
      text-align: center;
    }
    
    /* 关于区块 */
    .about-grid {
      display: flex;
      gap: 50px;
      align-items: center;
    }
    .about-stats {
      display: flex;
      gap: 30px;
      margin-top: 28px;
    }
    .stat-item h3 {
      font-size: 40px;
      color: var(--gold);
      font-weight: 700;
    }
    
    /* 服务卡片错落 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 48px;
    }
    .service-card {
      background: white;
      border-radius: 24px;
      padding: 36px 28px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s;
      position: relative;
    }
    .service-card:nth-child(2) {
      transform: translateY(-16px);
      background: #F0F4FA;
    }
    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
      border: 1px solid var(--cyan);
    }
    .service-icon {
      font-size: 32px;
      color: var(--cyan);
      margin-bottom: 20px;
    }
    
    /* 优势 */
    .advantage-numbers {
      display: flex;
      justify-content: space-around;
      margin: 40px 0;
    }
    
    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    .case-card {
      background: white;
      border-radius: 24px;
      overflow: hidden;
      display: flex;
      box-shadow: var(--shadow-sm);
    }
    .case-card img {
      width: 45%;
      object-fit: cover;
    }
    
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    
    /* 联系表单 */
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 16px;
      border: 1px solid #DDE3EA;
      border-radius: 16px;
      background: #F4F7FC;
      margin-bottom: 18px;
    }
    .contact-form input:focus {
      border-color: var(--cyan);
      box-shadow: 0 0 0 3px rgba(0,194,255,0.2);
    }
    
    /* 页脚 */
    .footer {
      background: var(--deep-blue);
      color: #B0C4DE;
      padding: 60px 0 30px;
    }
    
    @media (max-width: 768px) {
      .services-grid, .cases-grid {
        grid-template-columns: 1fr;
      }
      .service-card:nth-child(2) {
        transform: none;
      }
    }