/* roulang page: index */
:root {
      --primary: #0A6EBD;
      --primary-light: #E8F4FD;
      --accent: #FF6B4A;
      --accent-hover: #E85D3E;
      --bg: #FBFBFB;
      --bg-alt: #F4F7FA;
      --text-main: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #8C8C8C;
      --white: #FFFFFF;
      --border: #E5E7EB;
      --success: #10B981;
      --warning: #F59E0B;
      --shadow-sm: 0 2px 16px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.10);
      --radius: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
      --font-title: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      --font-mono: "DIN Alternate", "SF Mono", "Menlo", monospace;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-body);
      background: var(--bg);
      color: var(--text-body);
      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, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
      width: 100%;
    }
    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 22px;
      color: var(--text-main);
    }
    .logo svg {
      width: 36px;
      height: 36px;
    }
    .nav-links {
      display: flex;
      gap: 28px;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      color: var(--text-body);
      font-weight: 500;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
      border-bottom-color: var(--accent);
    }
    .nav-cta {
      background: var(--accent);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      box-shadow: 0 4px 10px rgba(255,107,74,0.3);
    }
    .nav-cta:hover {
      background: var(--accent-hover);
      transform: scale(1.03);
      box-shadow: 0 6px 14px rgba(255,107,74,0.4);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2.5px;
      background: var(--text-main);
      border-radius: 2px;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 300px;
      height: 100vh;
      background: white;
      box-shadow: -5px 0 20px rgba(0,0,0,0.1);
      z-index: 1100;
      flex-direction: column;
      padding: 80px 24px 40px;
      gap: 24px;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.open {
      transform: translateX(0);
      display: flex;
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--text-main);
    }
    .overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0,0,0,0.4);
      z-index: 1050;
      display: none;
    }
    .overlay.show {
      display: block;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-family: var(--font-title);
      font-size: 32px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 18px;
      margin-bottom: 48px;
    }
    /* 卡片通用 */
    .card {
      background: var(--white);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      padding: 32px;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    /* Hero */
    .hero {
      padding-top: 140px;
      background: linear-gradient(135deg, #FBFBFB 0%, #E8F4FD 100%);
      min-height: 85vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-content {
      display: flex;
      gap: 48px;
      align-items: center;
    }
    .hero-left h1 {
      font-family: var(--font-title);
      font-size: 44px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    .hero-left .sub {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.03);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .hero-right img {
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.15);
      max-width: 100%;
    }
    /* 痛点 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }
    .pain-card {
      background: #FFF9F7;
      border-left: 4px solid var(--accent);
      padding: 28px;
      border-radius: var(--radius);
    }
    /* 方案卡片 */
    .solution-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 24px;
    }
    .solution-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 16px;
    }
    /* 数据 */
    .stats-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 40px;
      justify-content: center;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
    }
    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }
    .testimonial-card {
      background: white;
      padding: 28px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .testimonial-card::before {
      content: "“";
      font-size: 64px;
      color: var(--primary);
      opacity: 0.2;
      position: absolute;
      top: 10px;
      left: 20px;
    }
    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius);
      box-shadow: 0 2px 8px rgba(0,0,0,0.03);
      border: 1px solid var(--border);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #F8FBFF;
      padding: 0 24px;
    }
    .faq-item.open .faq-answer {
      padding: 0 24px 20px;
      max-height: 200px;
    }
    /* CTA 区域 */
    .cta-section {
      background: var(--primary);
      text-align: center;
      color: white;
    }
    .cta-section h2 {
      color: white;
    }
    /* 页脚 */
    .footer {
      background: #1A1A1A;
      color: #B0B0B0;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }
    .footer a:hover {
      color: white;
    }
    @media (max-width: 1024px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .hero-left h1 {
        font-size: 32px;
      }
      .section-title {
        font-size: 26px;
      }
      .stats-grid {
        gap: 24px;
      }
      .stat-number {
        font-size: 36px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }