/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary-red: #E74C3C;
      --primary-deep-red: #C0392B;
      --secondary-slate: #2C3E50;
      --accent-gold: #F39C12;
      --success-green: #27AE60;
      --bg-light: #F9FAFB;
      --card-white: #FFFFFF;
      --text-heading: #1E293B;
      --text-body: #475569;
      --text-muted: #94A3B8;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
      --shadow-hover: 0 12px 28px rgba(0, 0, 0, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-full: 50px;
      --transition: 0.2s ease;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Segoe UI', 'Microsoft YaHei', system-ui, sans-serif;
    }

    /* ----- Reset & Base ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.6;
      -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: var(--font-body);
      transition: var(--transition);
      border: none;
      background: none;
    }
    ul {
      list-style: none;
    }

    /* ----- 容器 ----- */
    .container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }

    /* ----- 导航 (卡片化控制面板) ----- */
    .main-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      padding: 1rem 0;
      margin-bottom: 0;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .logo {
      font-family: var(--font-heading);
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--secondary-slate);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: 0.5px;
    }
    .logo i {
      color: var(--primary-red);
      font-size: 2rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .nav-links a {
      padding: 0.6rem 1.2rem;
      border-radius: var(--radius-btn);
      font-weight: 500;
      color: var(--text-body);
      background: transparent;
      display: inline-block;
    }
    .nav-links a:hover {
      background: rgba(231, 76, 60, 0.08);
      color: var(--primary-red);
    }
    .nav-cta {
      background: var(--primary-red) !important;
      color: white !important;
      font-weight: 600;
      box-shadow: 0 4px 10px rgba(231, 76, 60, 0.3);
    }
    .nav-cta:hover {
      background: var(--primary-deep-red) !important;
      color: white !important;
      box-shadow: 0 6px 14px rgba(192, 57, 43, 0.4);
    }
    .mobile-menu-toggle {
      display: none;
      font-size: 1.8rem;
      color: var(--secondary-slate);
      background: none;
      border: none;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        margin-top: 1rem;
        gap: 0.3rem;
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .nav-links a {
        text-align: center;
        padding: 0.8rem;
      }
    }

    /* ----- 板块间距 ----- */
    section {
      padding: 5rem 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 3rem 0;
      }
    }

    /* ----- 首屏 Hero ----- */
    .hero {
      background: linear-gradient(135deg, #fef2f2 0%, #fff5f0 100%);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 3rem;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 45%;
    }
    .hero-image {
      flex: 1 1 45%;
      text-align: center;
      position: relative;
    }
    .hero-image img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-md);
      margin: 0 auto;
    }
    .hero h1 {
      font-family: var(--font-heading);
      font-size: 2.8rem;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 1.5rem;
      background: linear-gradient(135deg, #E74C3C, #F39C12);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero .pain-point {
      font-size: 1.1rem;
      color: var(--text-muted);
      text-decoration: line-through;
      margin-bottom: 1rem;
      display: inline-block;
    }
    .hero .subtitle {
      font-size: 1.25rem;
      color: var(--text-body);
      margin-bottom: 2rem;
      line-height: 1.7;
    }
    .hero-actions {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary-red);
      color: white;
      font-weight: 600;
      padding: 0.9rem 2.2rem;
      border-radius: var(--radius-btn);
      font-size: 1rem;
      box-shadow: 0 6px 16px rgba(231, 76, 60, 0.25);
      display: inline-flex;
      align-items: center;
      gap: 6px;
      border: none;
    }
    .btn-primary:hover {
      background: var(--primary-deep-red);
      box-shadow: 0 8px 20px rgba(192, 57, 43, 0.4);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-red);
      color: var(--primary-red);
      font-weight: 600;
      padding: 0.9rem 2.2rem;
      border-radius: var(--radius-btn);
      font-size: 1rem;
    }
    .btn-outline:hover {
      background: var(--primary-red);
      color: white;
      border-color: var(--primary-red);
    }
    @media (max-width: 768px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      .hero h1 {
        font-size: 2.2rem;
      }
      .hero-actions {
        justify-content: center;
      }
    }

    /* 卡片通用样式 */
    .card {
      background: var(--card-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      padding: 2rem;
      height: 100%;
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
    }
    @media (max-width: 992px) {
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 600px) {
      .grid-3, .grid-2 {
        grid-template-columns: 1fr;
      }
    }

    .section-title {
      font-family: var(--font-heading);
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-heading);
      margin-bottom: 0.75rem;
      text-align: center;
    }
    .section-subtitle {
      color: var(--text-muted);
      text-align: center;
      margin-bottom: 3rem;
      font-size: 1.1rem;
    }

    /* 解决方案卡片 */
    .solution-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      border-radius: 8px;
      margin-bottom: 1.5rem;
    }
    .card h3 {
      font-size: 1.5rem;
      color: var(--secondary-slate);
      margin-bottom: 0.8rem;
    }
    .feature-list {
      margin: 1rem 0 1.5rem;
      color: var(--text-body);
    }
    .feature-list li {
      margin-bottom: 0.5rem;
      display: flex;
      align-items: baseline;
      gap: 0.5rem;
    }
    .feature-list i {
      color: var(--primary-red);
      font-size: 0.9rem;
    }

    /* 成果数据 */
    .results-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 2rem;
      justify-content: center;
    }
    .stat-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      text-align: center;
      flex: 1 1 200px;
      min-width: 180px;
      box-shadow: var(--shadow-sm);
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--primary-red);
    }
    .progress-bar {
      height: 8px;
      background: #e9ecef;
      border-radius: 4px;
      margin: 1rem 0;
      overflow: hidden;
    }
    .progress-fill {
      height: 100%;
      background: linear-gradient(90deg, #E74C3C, #F39C12);
      width: 0%;
    }

    /* 证言 */
    .testimonial-card {
      background: #f8fafc;
      padding: 2rem;
      border-radius: var(--radius-card);
      display: flex;
      gap: 1.5rem;
      align-items: flex-start;
    }
    .avatar {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      object-fit: cover;
    }
    .stars {
      color: var(--accent-gold);
      letter-spacing: 2px;
    }

    /* FAQ */
    .faq-item {
      background: var(--card-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      margin-bottom: 1rem;
      overflow: hidden;
    }
    .faq-question {
      background: #f1f5f9;
      padding: 1.2rem 1.8rem;
      font-weight: 600;
      color: var(--text-heading);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 1.8rem 1.2rem;
      color: var(--text-body);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 区域 */
    .cta-final {
      background: var(--secondary-slate);
      color: white;
      text-align: center;
      border-radius: 0;
    }
    .cta-final h2 {
      font-size: 2.2rem;
      margin-bottom: 1rem;
    }
    .btn-light {
      background: white;
      color: var(--primary-red);
      font-weight: 700;
    }

    /* 页脚 */
    .footer {
      background: #1e293b;
      color: #cbd5e1;
      padding: 3rem 0 2rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }