/* roulang page: index */
/* ----- 设计令牌 & 全局重置 ----- */
    :root {
      --deep-blue: #0A1F3F;
      --mid-blue: #1E4B8F;
      --energy-purple: #6C3CE1;
      --electric-green: #00F5A0;
      --surface-dark: rgba(255,255,255,0.04);
      --border-subtle: rgba(108,60,225,0.18);
      --text-primary: #FFFFFF;
      --text-secondary: #B0C4DE;
      --text-dark: #0A1F3F;
      --text-muted-dark: #475569;
      --card-bg-light: #F8FAFC;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --radius-full: 50px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.25);
      --shadow-hover: 0 16px 40px rgba(108,60,225,0.25);
      --transition-smooth: all 0.3s ease;
      --container-max: 1280px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      background-color: #050B14;
      color: var(--text-secondary);
      line-height: 1.6;
      font-size: 16px;
      overflow-x: hidden;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, input, select, textarea {
      font-family: inherit;
    }

    /* ----- 导航栏（沉浸式固定） ----- */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10, 31, 63, 0.88);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid transparent;
      background-image: linear-gradient(rgba(10,31,63,0.9), rgba(10,31,63,0.9)), linear-gradient(90deg, #1E4B8F, #6C3CE1);
      background-origin: border-box;
      background-clip: padding-box, border-box;
      z-index: 1000;
      display: flex;
      align-items: center;
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 28px;
      font-weight: 800;
      letter-spacing: 1px;
      background: linear-gradient(135deg, #FFFFFF 0%, #00F5A0 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      background: none;
      -webkit-text-fill-color: var(--electric-green);
      font-size: 32px;
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-menu a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-secondary);
      padding: 8px 0;
      position: relative;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--electric-green);
      transition: width 0.3s;
    }
    .nav-menu a:hover {
      color: var(--electric-green);
    }
    .nav-menu a:hover::after {
      width: 100%;
    }
    .nav-menu a.active {
      color: var(--electric-green);
    }
    .nav-menu a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 28px;
      height: 3px;
      background: white;
      border-radius: 4px;
      transition: 0.3s;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10, 31, 63, 0.98);
        backdrop-filter: blur(30px);
        flex-direction: column;
        align-items: center;
        padding: 32px 0;
        gap: 28px;
        transform: translateY(-120%);
        transition: transform 0.4s ease;
        border-bottom: 1px solid var(--energy-purple);
      }
      .nav-menu.active {
        transform: translateY(0);
      }
      .hamburger {
        display: flex;
      }
      .nav-menu a {
        font-size: 20px;
      }
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: radial-gradient(circle at 30% 40%, rgba(30,75,143,0.5) 0%, #050B14 80%);
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      overflow: hidden;
    }
    .hero-bg-img {
      position: absolute;
      inset: 0;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25;
      z-index: 0;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      padding: 0 24px;
    }
    .hero h1 {
      font-size: 52px;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: white;
      margin-bottom: 20px;
      background: linear-gradient(to right, #fff, #e0f2fe);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero .lead {
      font-size: 18px;
      color: #B0C4DE;
      margin-bottom: 36px;
    }
    .cta-group {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, #1E4B8F, #6C3CE1);
      color: white;
      padding: 14px 36px;
      border-radius: 50px;
      font-weight: 600;
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 16px rgba(108,60,225,0.4);
      transition: 0.3s;
    }
    .btn-primary:hover {
      box-shadow: 0 8px 24px rgba(0,245,160,0.5);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--electric-green);
      color: var(--electric-green);
      padding: 14px 36px;
      border-radius: 50px;
      font-weight: 600;
      transition: 0.3s;
    }
    .btn-outline:hover {
      background: rgba(0,245,160,0.1);
    }
    .floating-badge {
      position: absolute;
      bottom: 40px;
      right: 40px;
      background: rgba(10,31,63,0.8);
      backdrop-filter: blur(12px);
      padding: 12px 24px;
      border-radius: 40px;
      border: 1px solid var(--electric-green);
      color: var(--electric-green);
      font-weight: 600;
      animation: pulse 2s infinite;
    }
    @keyframes pulse {
      0% { box-shadow: 0 0 0 0 rgba(0,245,160,0.5); }
      70% { box-shadow: 0 0 20px 10px rgba(0,245,160,0); }
      100% { box-shadow: 0 0 0 0 rgba(0,245,160,0); }
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
      text-align: center;
    }
    .title-underline {
      width: 80px;
      height: 4px;
      background: var(--electric-green);
      margin: 0 auto 48px;
      border-radius: 4px;
    }

    /* 数据战绩 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--surface-dark);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      padding: 32px 16px;
      text-align: center;
      backdrop-filter: blur(8px);
      transition: 0.3s;
    }
    .stat-card:hover {
      border-color: var(--electric-green);
      transform: translateY(-4px);
    }
    .stat-number {
      font-size: 48px;
      font-weight: 900;
      color: var(--electric-green);
      font-family: 'DIN Alternate', 'Impact', sans-serif;
    }
    .stat-label {
      color: #B0C4DE;
      margin-top: 8px;
    }

    /* 服务卡片 2x2 不等宽 */
    .services-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
    }
    .service-card {
      background: rgba(255,255,255,0.03);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      padding: 32px;
      transition: 0.3s;
    }
    .service-card:hover {
      border-color: var(--electric-green);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 180px;
      background-size: cover;
      border-radius: 12px;
      margin-bottom: 20px;
    }
    .tag {
      display: inline-block;
      background: rgba(108,60,225,0.2);
      color: #B0C4DE;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      margin-right: 8px;
    }

    /* 案例对比 */
    .cases-compare {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
    }
    .case-card {
      flex: 1;
      background: #0f1a2b;
      border-radius: var(--radius-lg);
      padding: 24px;
      border: 1px solid var(--border-subtle);
    }
    .case-highlight {
      color: var(--electric-green);
      font-weight: 700;
      font-size: 24px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      color: white;
      cursor: pointer;
    }

    /* 表单 */
    .contact-form input, .contact-form select, .contact-form textarea {
      width: 100%;
      background: rgba(255,255,255,0.08);
      border: 1px solid rgba(255,255,255,0.15);
      border-radius: 8px;
      padding: 14px;
      color: white;
      margin-bottom: 16px;
    }
    .contact-form input:focus {
      border-color: var(--electric-green);
      outline: none;
    }
    .btn-submit {
      width: 100%;
      background: linear-gradient(135deg, #1E4B8F, #6C3CE1);
      border: none;
      color: white;
      padding: 16px;
      border-radius: 50px;
      font-weight: 700;
      cursor: pointer;
    }

    footer {
      background: #0A1F3F;
      padding: 60px 0 30px;
    }

    @media (max-width: 768px) {
      .hero h1 { font-size: 32px; }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .services-grid { grid-template-columns: 1fr; }
    }