/* roulang page: index */
:root {
      --primary: #FF8C00;
      --primary-light: #FFB347;
      --primary-gradient: linear-gradient(135deg, #FF8C00 0%, #FFB347 100%);
      --secondary: #2C3E50;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --text-dark: #1F2329;
      --text-gray: #86909C;
      --bg-light: #F5F6FA;
      --white: #FFFFFF;
      --card-shadow: 0 4px 20px rgba(0,0,0,0.04), 0 1px 4px rgba(0,0,0,0.02);
      --card-hover-shadow: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-pill: 24px;
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-family);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
      border-radius: var(--radius-card);
    }
    button, input {
      font-family: inherit;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      z-index: 1000;
      transition: var(--transition);
    }
    .header.scrolled {
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary-gradient);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 18px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-dark);
      transition: color var(--transition);
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .search-trigger {
      background: var(--bg-light);
      border: none;
      border-radius: var(--radius-pill);
      padding: 8px 20px;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-gray);
      font-size: 14px;
      cursor: pointer;
      transition: var(--transition);
    }
    .search-trigger:hover {
      background: #eee;
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
      flex-direction: column;
      gap: 5px;
      z-index: 1001;
    }
    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-dark);
      transition: var(--transition);
      border-radius: 2px;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: white;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 32px;
      z-index: 999;
      font-size: 20px;
    }
    .mobile-menu.active {
      display: flex;
    }
    /* Hero */
    .hero {
      background: var(--primary-gradient);
      padding: 120px 0 80px;
      position: relative;
      overflow: hidden;
    }
    .hero::after {
      content: "";
      position: absolute;
      inset: 0;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.08"><path d="M0 0h200v200H0z" fill="none"/><path d="M20 20h160v160H20z" fill="%23fff"/></svg>');
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
    }
    .hero-left {
      flex: 1;
      color: white;
    }
    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-left .subtitle {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 32px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: white;
      color: var(--primary);
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: var(--transition);
      box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }
    .btn-primary:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid white;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: white;
      color: var(--primary);
      transform: translateY(-2px);
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-right img {
      max-width: 100%;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.2);
      border: 4px solid white;
    }
    /* 通用区块 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--text-dark);
    }
    .section-sub {
      text-align: center;
      color: var(--text-gray);
      font-size: 18px;
      margin-bottom: 48px;
    }
    /* 优势卡片 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .adv-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      text-align: center;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
    }
    .adv-icon {
      font-size: 32px;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .adv-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--primary);
    }
    .adv-desc {
      color: var(--text-gray);
      font-size: 14px;
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
    }
    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .service-body {
      padding: 24px;
    }
    .service-body h3 {
      font-size: 24px;
      margin-bottom: 12px;
    }
    .feature-list {
      list-style: none;
      margin-top: 16px;
    }
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 14px;
      color: var(--text-gray);
      margin-bottom: 8px;
    }
    .feature-list li::before {
      content: "✓";
      color: var(--success);
      font-weight: bold;
    }
    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-text h3 {
      font-size: 28px;
      margin-bottom: 16px;
    }
    /* 案例卡片 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }
    .case-card {
      min-width: 300px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      scroll-snap-align: start;
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
    }
    .case-img {
      height: 180px;
      background-size: cover;
    }
    .case-body {
      padding: 20px;
    }
    .case-quote {
      font-style: italic;
      color: var(--text-gray);
      margin: 8px 0;
    }
    .case-stat {
      font-weight: 700;
      color: var(--primary);
      font-size: 24px;
    }
    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--card-shadow);
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 16px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-gray);
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }
    /* CTA */
    .cta-section {
      background: var(--bg-light);
      text-align: center;
      padding: 80px 0;
    }
    .cta-buttons {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-top: 32px;
      flex-wrap: wrap;
    }
    .btn-secondary {
      background: var(--bg-light);
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
    }
    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: white;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer a {
      color: #ccc;
      transition: color var(--transition);
    }
    .footer a:hover {
      color: var(--primary-light);
    }
    .copyright {
      text-align: center;
      color: var(--text-gray);
      font-size: 12px;
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 20px;
    }
    @media (max-width: 1024px) {
      .advantages-grid { grid-template-columns: repeat(2, 1fr); }
      .services-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links, .search-trigger { display: none; }
      .hamburger { display: flex; }
      .hero-grid { flex-direction: column; text-align: center; }
      .hero-left h1 { font-size: 32px; }
      .advantages-grid { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .section-title { font-size: 28px; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 520px) {
      .footer-grid { grid-template-columns: 1fr; }
      .btn-group { flex-direction: column; align-items: center; }
    }