/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary: #C8102E;
      --primary-dark: #A50D24;
      --gold: #D4AF37;
      --dark: #1C1C1C;
      --darker-bg: #2B2B2B;
      --light-bg: #F7F4EF;
      --white: #FFFFFF;
      --gray-text: #4A4A4A;
      --light-gray: #CCCCCC;
      --border-light: rgba(255,255,255,0.15);
      --card-shadow: 0 2px 8px rgba(0,0,0,0.04);
      --card-hover-shadow: 0 8px 30px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: 0.2s ease;
      --container-max: 1200px;
      --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
    }
    
    /* ----- 全局重置与基础 ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--light-bg);
      color: var(--gray-text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    ul {
      list-style: none;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (min-width: 1440px) {
      .container {
        max-width: 1320px;
      }
    }
    
    /* ----- 排版 ----- */
    h1, h2, h3, .h1, .h2, .h3 {
      color: var(--dark);
      font-weight: 700;
      letter-spacing: -0.3px;
      line-height: 1.3;
    }
    h1 {
      font-size: 48px;
    }
    h2 {
      font-size: 36px;
    }
    h3 {
      font-size: 22px;
      font-weight: 600;
    }
    .section-title {
      margin-bottom: 12px;
    }
    .section-subtitle {
      font-size: 18px;
      color: var(--gray-text);
      margin-bottom: 48px;
      max-width: 700px;
    }
    
    /* ----- 按钮系统 ----- */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      transition: background 0.2s, color 0.2s, transform 0.2s, box-shadow 0.2s;
      border: 2px solid transparent;
      background: transparent;
    }
    .btn-primary {
      background: var(--primary);
      color: var(--white);
      border-color: var(--primary);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      border-color: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(200, 16, 46, 0.25);
    }
    .btn-secondary {
      background: transparent;
      color: var(--white);
      border-color: var(--white);
    }
    .btn-secondary:hover {
      background: var(--white);
      color: var(--dark);
      transform: translateY(-2px);
    }
    .btn-outline-dark {
      background: transparent;
      color: var(--dark);
      border-color: var(--dark);
    }
    .btn-outline-dark:hover {
      background: var(--dark);
      color: var(--white);
      transform: translateY(-2px);
    }
    .btn-light {
      background: var(--white);
      color: var(--primary);
      border-color: var(--white);
    }
    .btn-light:hover {
      background: #f0f0f0;
      border-color: #f0f0f0;
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    }
    
    /* ----- 导航 ----- */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.05);
      transition: box-shadow 0.3s;
    }
    .header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--dark);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--primary);
      font-size: 28px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--dark);
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .hamburger {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--dark);
      cursor: pointer;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background: var(--dark);
      color: white;
      padding: 24px;
      display: flex;
      flex-direction: column;
      gap: 24px;
      transition: right 0.3s ease;
      z-index: 1001;
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      color: white;
      font-size: 18px;
      font-weight: 500;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.2);
    }
    .mobile-menu .close-btn {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }
    
    @media (max-width: 1024px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
    }
    
    /* ----- Hero 首屏 ----- */
    .hero {
      background: linear-gradient(135deg, #1C1C1C 0%, #2B2B2B 100%);
      color: white;
      padding: 140px 0 100px;
      margin-top: 72px;
      position: relative;
      overflow: hidden;
    }
    .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;
      pointer-events: none;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
    }
    .hero-content {
      flex: 1;
    }
    .hero-content h1 {
      color: white;
      font-size: 52px;
      margin-bottom: 20px;
    }
    .hero-content p {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      max-width: 500px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      text-align: right;
    }
    .hero-visual img {
      border-radius: var(--radius-lg);
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
      max-width: 100%;
      height: auto;
    }
    .hero-badges {
      display: flex;
      gap: 20px;
      margin-top: 40px;
    }
    .badge-item {
      background: rgba(255,255,255,0.08);
      border: 1px solid rgba(255,255,255,0.2);
      border-radius: var(--radius-md);
      padding: 12px 20px;
      color: white;
      text-align: center;
    }
    .badge-number {
      font-size: 28px;
      font-weight: 700;
      color: var(--gold);
    }
    .badge-label {
      font-size: 13px;
      color: #ccc;
    }
    
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 40px;
      }
      .hero-visual {
        text-align: center;
        margin-top: 24px;
      }
      .hero-badges {
        justify-content: center;
      }
    }
    
    /* ----- 通用板块间距 ----- */
    section {
      padding: 100px 0;
    }
    
    /* ----- 核心优势卡片 ----- */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .feature-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--card-shadow);
      transition: transform 0.2s, box-shadow 0.2s;
      text-align: left;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
    }
    .feature-icon {
      width: 64px;
      height: 64px;
      background: rgba(200, 16, 46, 0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 28px;
      margin-bottom: 24px;
    }
    .feature-card h3 {
      margin-bottom: 12px;
    }
    
    /* ----- 服务产品区 2列大卡 ----- */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: transform 0.2s, box-shadow 0.2s;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
    }
    .service-img {
      height: 220px;
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-body {
      padding: 28px 32px 32px;
    }
    .service-body h3 {
      margin-bottom: 12px;
    }
    .service-list {
      margin: 16px 0;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .service-list li {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 15px;
    }
    .service-list i {
      color: var(--primary);
    }
    .text-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      margin-top: 8px;
    }
    
    /* ----- 数据成果深色区 ----- */
    .results {
      background: var(--dark);
      color: white;
    }
    .results .section-title {
      color: white;
    }
    .results-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 24px;
      margin-top: 40px;
    }
    .stat-badge {
      background: rgba(255,255,255,0.05);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: var(--radius-md);
      padding: 24px 28px;
      text-align: center;
      flex: 1;
      min-width: 150px;
    }
    .stat-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--gold);
    }
    .stat-desc {
      font-size: 14px;
      color: #ccc;
      margin-top: 8px;
    }
    
    /* ----- 客户证言 ----- */
    .testimonials {
      background: linear-gradient(180deg, #FDFBF7 0%, #F7F4EF 100%);
    }
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .testimonial-card {
      background: #FAFAFA;
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--card-shadow);
    }
    .testimonial-icon {
      color: var(--gold);
      font-size: 28px;
      margin-bottom: 16px;
    }
    .testimonial-text {
      font-style: italic;
      margin-bottom: 20px;
      color: var(--dark);
    }
    .testimonial-author {
      font-weight: 600;
      color: var(--dark);
    }
    .testimonial-role {
      font-size: 14px;
      color: var(--gray-text);
    }
    
    /* ----- FAQ 手风琴 ----- */
    .faq-container {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid #ddd;
      margin-bottom: 8px;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--dark);
      cursor: pointer;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: #F7F4EF;
      border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 20px 20px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    
    /* ----- CTA 全宽红色 ----- */
    .cta-section {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-section h2 {
      color: white;
      margin-bottom: 16px;
    }
    .cta-section .btn {
      margin-top: 24px;
    }
    
    /* ----- 页脚 ----- */
    .footer {
      background: var(--dark);
      color: #CCCCCC;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: white;
    }
    .footer-desc {
      margin-top: 12px;
      font-size: 14px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 16px;
      font-size: 16px;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a:hover {
      color: var(--primary);
    }
    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 20px;
      display: flex;
      justify-content: space-between;
      font-size: 14px;
    }
    
    @media (max-width: 1024px) {
      .features-grid,
      .testimonials-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .features-grid,
      .services-grid,
      .testimonials-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      h1 { font-size: 40px; }
      h2 { font-size: 30px; }
    }