/* roulang page: index */
:root {
      --primary: #FF4D2E;
      --primary-dark: #E03A1C;
      --secondary: #1A1A2E;
      --accent: #00C9A7;
      --white: #FFFFFF;
      --gray-light: #F5F6FA;
      --gray-border: #DDDDDD;
      --text-main: #333333;
      --text-muted: #666666;
      --text-light: #CCCCCC;
      --font-heading: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-number: 'DIN Alternate', 'Inter', sans-serif;
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-sm: 12px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --transition: 0.3s ease;
      --container-max: 1200px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-heading);
      color: var(--text-main);
      background: var(--white);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.2;
    }
    h1 {
      font-size: 48px;
      font-weight: 800;
      color: var(--white);
    }
    h2 {
      font-size: 36px;
      color: var(--secondary);
      margin-bottom: 16px;
    }
    h3 {
      font-size: 22px;
      font-weight: 600;
      color: var(--secondary);
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-heading);
      font-weight: 600;
      border: none;
      background: none;
      transition: all var(--transition);
    }
    .section {
      padding: 80px 0;
    }
    .section-dark {
      background: var(--secondary);
      color: var(--white);
    }
    .section-gray {
      background: var(--gray-light);
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,0,0,0.05);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--secondary);
      letter-spacing: -0.5px;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 16px;
      color: #555;
      font-weight: 500;
      position: relative;
      padding: 8px 0;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.03);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: var(--white);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: var(--secondary);
      transition: var(--transition);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      height: calc(100vh - var(--nav-height));
      background: var(--secondary);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 40px;
      z-index: 999;
    }
    .mobile-menu a {
      color: var(--white);
      font-size: 24px;
      font-weight: 600;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #1A1A2E 0%, #FF4D2E 100%);
      position: relative;
      overflow: hidden;
      margin-top: 0;
      padding-top: var(--nav-height);
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.15;
      mix-blend-mode: overlay;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin: 0 auto;
      text-align: center;
      color: var(--white);
    }
    .hero h1 {
      margin-bottom: 24px;
    }
    .hero .subtitle {
      font-size: 20px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 40px;
    }
    .hero-actions {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }
    /* 服务卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
      margin-top: 40px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }
    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .icon-box {
      width: 64px;
      height: 64px;
      margin-bottom: 24px;
      color: var(--primary);
    }
    .service-card h3 {
      margin-bottom: 12px;
    }
    .service-card p {
      color: var(--text-muted);
      margin-bottom: 20px;
      font-size: 15px;
    }
    .text-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    /* 数据徽章 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 30px;
    }
    .stat-badge {
      background: var(--white);
      border-radius: var(--radius-sm);
      padding: 28px 20px;
      text-align: center;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .stat-badge:hover {
      transform: translateY(-3px);
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 40px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.1;
    }
    .stat-label {
      font-size: 14px;
      color: var(--text-muted);
      margin-top: 8px;
    }
    /* 案例卡片 */
    .case-row {
      display: flex;
      gap: 30px;
      margin-top: 40px;
    }
    .case-card {
      display: flex;
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      flex: 1;
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .case-img {
      width: 40%;
      min-height: 220px;
      object-fit: cover;
    }
    .case-info {
      padding: 28px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .tag {
      background: var(--gray-light);
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 12px;
    }
    .case-meta {
      color: var(--accent);
      font-weight: 700;
      margin: 12px 0;
    }
    /* 解决方案交替 */
    .solution-block {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-top: 50px;
    }
    .solution-block.reverse {
      flex-direction: row-reverse;
    }
    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      background: var(--gray-light);
    }
    .solution-text {
      flex: 1;
    }
    .solution-text ul {
      list-style: none;
      margin: 20px 0;
    }
    .solution-text li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .solution-text li::before {
      content: "✓";
      color: var(--accent);
      font-weight: bold;
    }
    /* FAQ */
    .faq-list {
      margin-top: 30px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: var(--gray-light);
      border-radius: var(--radius-btn);
      overflow: hidden;
    }
    .faq-question {
      width: 100%;
      padding: 20px 28px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      background: transparent;
      border: none;
      text-align: left;
      color: var(--secondary);
    }
    .faq-icon {
      font-size: 24px;
      color: var(--primary);
      transition: var(--transition);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: var(--white);
      padding: 0 28px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 0 28px 20px;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* 联系CTA */
    .contact-wrapper {
      display: flex;
      gap: 50px;
      margin-top: 40px;
    }
    .contact-form {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .contact-form input, .contact-form textarea {
      padding: 12px 16px;
      border: 1px solid var(--gray-border);
      border-radius: var(--radius-btn);
      font-family: var(--font-heading);
      outline: none;
    }
    .contact-form input:focus, .contact-form textarea:focus {
      border-color: var(--primary);
    }
    .contact-info {
      flex: 1;
      color: var(--white);
      padding-top: 20px;
    }
    .contact-info p {
      margin-bottom: 20px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: var(--text-light);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer h4 {
      color: var(--white);
      margin-bottom: 20px;
      font-size: 18px;
    }
    .footer a:hover {
      color: var(--primary);
    }
    .social-icons {
      display: flex;
      gap: 16px;
      margin-top: 20px;
    }
    .social-circle {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      border: 1px solid var(--text-light);
      display: flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
    }
    .social-circle:hover {
      background: var(--primary);
      border-color: var(--primary);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }
    @media (max-width: 1024px) {
      .cards-grid { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .case-card { flex-direction: column; }
      .case-img { width: 100%; height: 200px; }
    }
    @media (max-width: 768px) {
      h1 { font-size: 32px; }
      h2 { font-size: 28px; }
      .section { padding: 60px 0; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .cards-grid, .stats-grid, .footer-grid { grid-template-columns: 1fr; }
      .hero-actions { flex-direction: column; align-items: center; }
      .solution-block, .solution-block.reverse { flex-direction: column; }
      .contact-wrapper { flex-direction: column; }
      .case-row { flex-direction: column; }
      .container { padding: 0 20px; }
    }
    .mobile-menu.active { display: flex; }