/* roulang page: index */
:root {
      --primary: #0A1F3F;
      --secondary: #00B4D8;
      --accent: #FF6B35;
      --success: #2EC4B6;
      --bg: #F4F7FC;
      --card-bg: #FFFFFF;
      --text-main: #1A2B3C;
      --text-muted: #5F6B7A;
      --border: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(10,31,63,0.06), 0 1px 2px rgba(10,31,63,0.04);
      --shadow-hover: 0 6px 16px rgba(10,31,63,0.1);
      --radius: 8px;
      --transition: 0.2s ease;
      --container-max: 1200px;
      --section-padding: 100px;
      --header-height: 64px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "WenQuanYi Micro Hei", sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button, input {
      font-family: inherit;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: #FFFFFF;
      box-shadow: 0 1px 4px rgba(10,31,63,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }
    .logo i {
      color: var(--secondary);
      font-size: 1.6rem;
    }
    .nav {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav a {
      font-size: 0.9rem;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 4px 0;
    }
    .nav a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--secondary);
      transition: width 0.2s ease;
    }
    .nav a:hover {
      color: var(--secondary);
    }
    .nav a:hover::after {
      width: 100%;
    }
    .btn-nav {
      background: var(--secondary);
      color: #fff;
      font-weight: 600;
      padding: 8px 18px;
      border-radius: var(--radius);
      font-size: 0.9rem;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-nav:hover {
      filter: brightness(0.9);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: var(--transition);
    }
    .mobile-nav {
      display: none;
      position: fixed;
      top: var(--header-height);
      left: 0;
      width: 100%;
      background: rgba(10,31,63,0.96);
      backdrop-filter: blur(12px);
      flex-direction: column;
      padding: 32px 24px;
      gap: 24px;
      z-index: 99;
      transform: translateY(-10px);
      opacity: 0;
      transition: 0.25s ease;
    }
    .mobile-nav.active {
      display: flex;
      transform: translateY(0);
      opacity: 1;
    }
    .mobile-nav a {
      color: #fff;
      font-size: 1.2rem;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      padding-bottom: 12px;
    }
    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(135deg, #F4F7FC 0%, #E8EFF9 100%);
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(rgba(10,31,63,0.03) 1px, transparent 1px);
      background-size: 30px 30px;
      pointer-events: none;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.25;
      color: var(--primary);
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }
    .hero-text h1 span {
      color: var(--secondary);
    }
    .hero-sub {
      font-size: 1.15rem;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent);
      color: #fff;
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius);
      border: none;
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition);
      box-shadow: 0 4px 10px rgba(255,107,53,0.25);
    }
    .btn-primary:hover {
      filter: brightness(0.9);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius);
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition);
    }
    .btn-secondary:hover {
      background: rgba(10,31,63,0.05);
    }
    .hero-image {
      flex: 1;
      background: rgba(255,255,255,0.6);
      backdrop-filter: blur(8px);
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border);
    }
    .hero-image img {
      width: 100%;
      object-fit: cover;
    }
    /* sections */
    section {
      padding: var(--section-padding) 0;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 48px;
      text-align: center;
    }
    .pain-solution {
      display: flex;
      gap: 40px;
      align-items: flex-start;
    }
    .pain-col, .solution-col {
      flex: 1;
      background: var(--card-bg);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .pain-col h3, .solution-col h3 {
      font-size: 1.4rem;
      margin-bottom: 24px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .list-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 16px;
      font-size: 1rem;
    }
    .icon-warn {
      color: var(--accent);
      font-size: 1.2rem;
    }
    .icon-check {
      color: var(--success);
    }
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .feature-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-hover);
    }
    .feature-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 6px;
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: 1.2rem;
      font-weight: 600;
      color: var(--secondary);
      margin-bottom: 8px;
    }
    .data-strip {
      background: var(--primary);
      color: white;
      padding: 32px 0;
      display: flex;
      justify-content: center;
      gap: 60px;
      flex-wrap: wrap;
      text-align: center;
    }
    .data-item strong {
      font-size: 2rem;
      font-weight: 700;
      color: var(--secondary);
      display: block;
    }
    .partners {
      display: flex;
      justify-content: center;
      gap: 40px;
      flex-wrap: wrap;
      margin: 40px 0;
    }
    .partner-logo {
      filter: grayscale(1);
      opacity: 0.6;
      transition: var(--transition);
      height: 32px;
      background: #ccc;
      width: 100px;
      border-radius: 4px;
    }
    .partner-logo:hover {
      filter: none;
      opacity: 1;
    }
    .testimonial-card {
      background: var(--card-bg);
      padding: 32px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .testimonial-card::before {
      content: "“";
      font-size: 4rem;
      color: var(--secondary);
      opacity: 0.2;
      position: absolute;
      top: 10px;
      left: 20px;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      padding: 20px 16px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: var(--card-bg);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F0F5FB;
      padding: 0 16px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 16px;
    }
    .cta-section {
      background: linear-gradient(105deg, #00B4D8 0%, #0A1F3F 100%);
      color: white;
      text-align: center;
    }
    .cta-form {
      display: flex;
      max-width: 480px;
      margin: 32px auto 0;
      gap: 12px;
    }
    .cta-form input {
      flex: 1;
      padding: 14px 16px;
      border-radius: var(--radius);
      border: none;
      background: white;
    }
    .footer {
      background: var(--primary);
      color: #E2E8F0;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
    }
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .pain-solution { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav { display: none; }
      .hamburger { display: flex; }
      .hero .container { flex-direction: column; }
      .hero-text h1 { font-size: 2rem; }
      .features-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
      .cta-form { flex-direction: column; }
      .section-title { font-size: 1.6rem; }
    }