/* roulang page: index */
:root {
      --primary: #E8453A;
      --primary-dark: #c0392b;
      --secondary: #1A1A2E;
      --accent: #F5A623;
      --light-bg: #FAFAFA;
      --dark-bg: #0F0F1A;
      --text-main: #1A1A2E;
      --text-secondary: #5C5C6E;
      --text-on-dark: #FFFFFF;
      --border-light: #E0E0E0;
      --gradient-brand: linear-gradient(135deg, #E8453A 0%, #F5A623 100%);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 12px 32px rgba(232,69,58,0.18);
      --radius-card: 20px;
      --radius-btn: 12px;
      --font-heavy: 'PingFang SC Heavy', 'Inter', 'Helvetica Neue', sans-serif;
      --font-semibold: 'PingFang SC Semibold', 'Inter', sans-serif;
      --font-regular: 'PingFang SC Regular', 'Inter', system-ui, sans-serif;
      --transition: 0.3s ease;
    }

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

    body {
      font-family: var(--font-regular);
      background-color: var(--light-bg);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 40px;
    }

    h1, h2, h3 {
      font-family: var(--font-heavy);
      font-weight: 700;
    }

    h2 {
      font-size: 36px;
      line-height: 44px;
      letter-spacing: -0.5px;
      color: var(--secondary);
      margin-bottom: 16px;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

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

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.35s ease, backdrop-filter 0.35s ease, box-shadow 0.35s ease;
      background: transparent;
      backdrop-filter: blur(0px);
    }

    .nav.scrolled {
      background: rgba(26, 26, 46, 0.88);
      backdrop-filter: blur(20px);
      box-shadow: 0 8px 24px rgba(0,0,0,0.25);
      padding: 12px 0;
    }

    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-family: var(--font-heavy);
      font-size: 24px;
      color: #fff;
      letter-spacing: 1px;
    }

    .logo img {
      height: 36px;
      width: auto;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      color: rgba(255,255,255,0.9);
      font-weight: 500;
    }

    .nav-links a {
      font-size: 16px;
      position: relative;
      padding-bottom: 4px;
      transition: color 0.2s;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--gradient-brand);
      transition: width 0.25s ease;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .btn-nav {
      background: var(--gradient-brand);
      color: #fff;
      border: none;
      padding: 10px 24px;
      border-radius: 30px;
      font-weight: 600;
      font-family: var(--font-semibold);
      cursor: pointer;
      transition: transform 0.2s, box-shadow 0.2s;
    }

    .btn-nav:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(232,69,58,0.4);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }

    .hamburger span {
      width: 26px;
      height: 2px;
      background: #fff;
      transition: 0.3s;
    }

    /* Hero */
    .hero {
      background: radial-gradient(circle at 20% 30%, #1e1e38 0%, var(--dark-bg) 90%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
      position: relative;
      overflow: hidden;
    }

    .hero-glow {
      position: absolute;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(232,69,58,0.25) 0%, transparent 70%);
      top: -100px;
      right: -100px;
      border-radius: 50%;
    }

    .hero .container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      position: relative;
      z-index: 2;
    }

    .hero-content {
      color: #fff;
    }

    .hero h1 {
      font-size: 48px;
      line-height: 56px;
      margin-bottom: 24px;
      font-weight: 800;
    }

    .dynamic-subtitle {
      font-size: 20px;
      font-weight: 400;
      color: rgba(255,255,255,0.8);
      margin-bottom: 40px;
      min-height: 32px;
    }

    .hero-badges {
      display: flex;
      gap: 16px;
      margin-bottom: 48px;
      flex-wrap: wrap;
    }

    .badge {
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(12px);
      border-radius: 40px;
      padding: 8px 20px;
      font-size: 15px;
      color: #fff;
      border: 1px solid rgba(255,255,255,0.2);
    }

    .badge strong {
      color: var(--accent);
      font-family: var(--font-heavy);
    }

    .btn-group {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--gradient-brand);
      border: none;
      color: #fff;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-size: 16px;
      cursor: pointer;
      transition: transform 0.25s, box-shadow 0.25s, background 0.25s;
      font-family: var(--font-semibold);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 28px rgba(232,69,58,0.45);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid transparent;
      background-image: linear-gradient(rgba(255,255,255,0), rgba(255,255,255,0)), var(--gradient-brand);
      background-origin: border-box;
      background-clip: padding-box, border-box;
      color: #fff;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: 0.3s;
    }

    .btn-outline:hover {
      background: var(--gradient-brand);
      color: #fff;
    }

    .hero-image img {
      border-radius: 32px;
      box-shadow: 0 30px 50px rgba(0,0,0,0.5);
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }

    /* 优势卡片 非对称 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 5fr 3fr 3fr;
      gap: 28px;
    }

    .adv-card {
      background: #fff;
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border-top: 4px solid transparent;
      position: relative;
    }

    .adv-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-card-hover);
      border-image: var(--gradient-brand) 1;
      border-top: 4px solid var(--primary);
    }

    .adv-icon {
      width: 60px;
      height: 60px;
      background: var(--gradient-brand);
      border-radius: 18px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: #fff;
      font-size: 28px;
    }

    .adv-card h3 {
      font-size: 22px;
      margin-bottom: 8px;
    }

    .data-badge {
      display: inline-block;
      background: #FFF3E0;
      color: var(--primary);
      font-weight: 700;
      border-radius: 20px;
      padding: 6px 16px;
      margin-top: 16px;
    }

    /* 服务横向滚动 */
    .service-scroll {
      display: flex;
      gap: 28px;
      overflow-x: auto;
      padding-bottom: 20px;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
    }

    .service-card {
      flex: 0 0 320px;
      background: #fff;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      scroll-snap-align: start;
    }

    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-card-hover);
    }

    .service-img {
      height: 180px;
      background-size: cover;
      border-radius: 20px 20px 0 0;
    }

    .service-info {
      padding: 24px;
    }

    /* 数据看板 */
    .data-dashboard {
      background: linear-gradient(180deg, #1A1A2E 0%, #0F0F1A 100%);
      color: #fff;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }

    .stat-number {
      font-size: 44px;
      font-weight: 700;
      color: var(--accent);
    }

    /* 步骤 */
    .steps-line {
      display: flex;
      justify-content: space-between;
      position: relative;
    }

    .step-item {
      text-align: center;
      flex: 1;
    }

    /* 案例网格 */
    .case-grid {
      display: grid;
      grid-template-columns: 7fr 5fr;
      gap: 24px;
    }

    .case-large, .case-small {
      border-radius: var(--radius-card);
      overflow: hidden;
      position: relative;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }

    .faq-item {
      background: #fff;
      border-radius: 12px;
      padding: 18px 24px;
      cursor: pointer;
      border-left: 3px solid transparent;
      transition: 0.25s;
    }

    .faq-item.active {
      border-left: 3px solid var(--primary);
      background: #F9F9FB;
    }

    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: #B0B0C0;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 992px) {
      .container { padding: 0 24px; }
      .advantages-grid { grid-template-columns: 1fr 1fr; }
      .hero .container { grid-template-columns: 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
      .case-grid { grid-template-columns: 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }