/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-light: #EEF1FE;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --bg-light: #F5F6FA;
      --white: #FFFFFF;
      --dark-bg: #1F2329;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --text-disabled: #C9CDD4;
      --border-light: #E8EAED;
      --radius-card: 16px;
      --radius-btn: 24px;
      --radius-input: 12px;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: all 0.25s ease;
      --max-width: 1200px;
      --padding-h: 48px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

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

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

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: var(--transition);
      background: transparent;
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
    }

    .navbar.scrolled {
      background: rgba(255,255,255,0.95);
      box-shadow: var(--shadow-card);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
    }

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

    .logo {
      font-size: 28px;
      font-weight: 700;
      letter-spacing: 1px;
      color: var(--white);
      transition: var(--transition);
      white-space: nowrap;
    }

    .navbar.scrolled .logo {
      color: var(--text-primary);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--white);
      font-size: 16px;
      transition: var(--transition);
      position: relative;
    }

    .navbar.scrolled .nav-links a {
      color: var(--text-primary);
    }

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

    .btn-nav {
      background: var(--primary);
      color: var(--white) !important;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      box-shadow: 0 2px 8px rgba(78,110,242,0.3);
      border: none;
      cursor: pointer;
    }

    .btn-nav:hover {
      filter: brightness(1.1);
      transform: translateY(-1px);
      box-shadow: 0 6px 16px rgba(78,110,242,0.4);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--white);
      transition: var(--transition);
    }

    .navbar.scrolled .hamburger span {
      background: var(--text-primary);
    }

    /* 移动端菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--white);
      z-index: 999;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 40px;
      font-size: 24px;
      font-weight: 500;
    }

    .mobile-menu.active {
      display: flex;
    }

    .mobile-menu a {
      color: var(--text-primary);
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #4E6EF2 0%, #6C8CFF 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 80px;
      color: var(--white);
    }

    .hero-bg-img {
      position: absolute;
      inset: 0;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.25;
      z-index: 0;
    }

    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
      flex-wrap: wrap;
    }

    .hero-text {
      flex: 1 1 500px;
    }

    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
    }

    .hero p {
      font-size: 18px;
      line-height: 1.6;
      margin-bottom: 40px;
      opacity: 0.9;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--white);
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      border: none;
      cursor: pointer;
    }

    .btn-primary:hover {
      background: #f0f2ff;
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid rgba(255,255,255,0.8);
      color: var(--white);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
      border-color: var(--white);
    }

    .hero-visual {
      flex: 1 1 400px;
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(8px);
      border-radius: 32px;
      padding: 24px;
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      justify-content: center;
    }

    .hero-card {
      background: var(--white);
      border-radius: 20px;
      padding: 20px;
      width: 120px;
      height: 120px;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-card);
      color: var(--primary);
      font-weight: bold;
    }

    /* 通用区块 */
    section {
      padding: 120px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 64px;
    }

    .section-title h2 {
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .section-title p {
      color: var(--text-secondary);
      font-size: 18px;
    }

    /* 优势卡片 - 错落 */
    .advantages-grid {
      display: flex;
      gap: 32px;
      justify-content: center;
      align-items: flex-start;
      flex-wrap: wrap;
    }

    .adv-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 40px 32px;
      flex: 1 1 280px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      position: relative;
    }

    .adv-card.middle {
      background: var(--primary-light);
      transform: translateY(-40px);
      box-shadow: var(--shadow-hover);
    }

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

    .adv-card.middle:hover {
      transform: translateY(-48px);
    }

    .adv-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 24px;
    }

    .adv-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 服务矩阵 */
    .service-row {
      display: flex;
      gap: 60px;
      align-items: center;
      margin-bottom: 100px;
      flex-wrap: wrap;
    }

    .service-row.reverse {
      flex-direction: row-reverse;
    }

    .service-img {
      flex: 1 1 400px;
      background: #E8EAED;
      border-radius: 24px;
      overflow: hidden;
      height: 320px;
    }

    .service-img img {
      width: 100%;
      height: 100%;
    }

    .service-text {
      flex: 1 1 400px;
    }

    .service-text h3 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 20px;
    }

    /* 数据深色区 */
    .data-section {
      background: var(--dark-bg);
      color: var(--white);
      padding: 100px 0;
    }

    .data-grid {
      display: flex;
      gap: 48px;
      justify-content: center;
      flex-wrap: wrap;
      text-align: center;
    }

    .data-item .number {
      font-size: 48px;
      font-weight: 700;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 20px 28px;
      margin-bottom: 16px;
      box-shadow: var(--shadow-card);
      cursor: pointer;
      border-left: 2px solid transparent;
      transition: var(--transition);
    }

    .faq-item.active {
      border-left: 2px solid var(--primary);
    }

    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #EEF1FE, #F5F6FA);
      text-align: center;
    }

    /* 页脚 */
    .footer {
      background: var(--white);
      padding: 60px 0 30px;
      border-top: 1px solid var(--border-light);
    }

    .footer-grid {
      display: flex;
      gap: 48px;
      flex-wrap: wrap;
      justify-content: space-between;
    }

    .footer-col p {
      color: var(--text-secondary);
    }

    @media (max-width: 992px) {
      .hero h1 { font-size: 40px; }
      .advantages-grid { flex-direction: column; align-items: center; }
      .adv-card.middle { transform: translateY(0); }
    }

    @media (max-width: 768px) {
      :root { --padding-h: 24px; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero .container { flex-direction: column; text-align: center; }
      .hero-buttons { justify-content: center; }
      section { padding: 80px 0; }
      .service-row, .service-row.reverse { flex-direction: column; }
    }

    @media (max-width: 576px) {
      .hero h1 { font-size: 32px; }
    }