/* roulang page: index */
:root {
      --primary: #E94E1B;
      --primary-dark: #C73E0D;
      --primary-light: #FFF0EB;
      --secondary: #1E1E1E;
      --accent: #0F62FE;
      --bg: #FAFAF7;
      --white: #FFFFFF;
      --gray-100: #E8E8E4;
      --gray-200: #DDDDDD;
      --gray-500: #555555;
      --gray-700: #333333;
      --gray-900: #1E1E1E;
      --text-muted: #999999;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --shadow-button: 0 8px 20px rgba(233,78,27,0.3);
      --radius-card: 16px;
      --radius-button: 50px;
      --transition: 0.25s ease;
      --container: 1200px;
      --space-section: 100px;
      --space-card: 24px;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-sans);
      background: var(--bg);
      color: var(--gray-700);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      color: var(--secondary);
    }

    h1 { font-size: 48px; line-height: 1.2; }
    h2 { font-size: 36px; line-height: 1.3; }
    h3 { font-size: 24px; line-height: 1.4; }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    img {
      max-width: 100%;
      display: block;
      height: auto;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      border: none;
      outline: none;
    }

    .btn-primary {
      background: linear-gradient(135deg, #E94E1B 0%, #C73E0D 100%);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-button);
      font-size: 16px;
      box-shadow: 0 4px 12px rgba(233,78,27,0.25);
    }

    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 8px 24px rgba(233,78,27,0.4);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 34px;
      border-radius: var(--radius-button);
      font-size: 16px;
    }

    .btn-outline:hover {
      background: var(--primary-light);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
    }

    section {
      padding: var(--space-section) 0;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid var(--gray-100);
      z-index: 1000;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--secondary);
      position: relative;
      padding-bottom: 6px;
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--secondary);
      background: none;
      border: none;
    }

    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      color: white;
    }

    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(233,78,27,0.8) 0%, rgba(199,62,13,0.9) 100%);
      opacity: 0.85;
      z-index: 1;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin: 0 auto;
    }

    .hero h1 {
      color: white;
      margin-bottom: 24px;
      text-shadow: 0 4px 12px rgba(0,0,0,0.2);
    }

    .hero-sub {
      font-size: 20px;
      opacity: 0.9;
      margin-bottom: 40px;
      font-weight: 400;
    }

    .hero-badges {
      display: flex;
      justify-content: center;
      gap: 24px;
      margin-top: 48px;
      flex-wrap: wrap;
    }

    .badge {
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(12px);
      padding: 12px 24px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 14px;
      color: white;
      border: 1px solid rgba(255,255,255,0.25);
    }

    /* 核心优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--space-card);
    }

    .adv-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .adv-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }

    .adv-icon {
      width: 64px;
      height: 64px;
      background: #F0F7FF;
      border-radius: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 28px;
      margin-bottom: 24px;
    }

    .adv-card h3 {
      margin-bottom: 12px;
    }

    .adv-card p {
      color: var(--gray-500);
    }

    /* 数据板块 */
    .data-section {
      background: var(--secondary);
      color: white;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }

    .stat-number {
      font-size: 56px;
      font-weight: 800;
      background: linear-gradient(135deg, #E94E1B, #FF7A45);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 8px;
    }

    .stat-label {
      font-size: 14px;
      opacity: 0.85;
    }

    /* 解决方案 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .solution-row.reverse {
      flex-direction: row-reverse;
    }

    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      aspect-ratio: 16/9;
    }

    .solution-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .solution-text {
      flex: 1;
    }

    .solution-text h2 {
      margin-bottom: 16px;
    }

    .orange-line {
      width: 48px;
      height: 4px;
      background: var(--primary);
      border-radius: 2px;
      margin-bottom: 24px;
    }

    .feature-list {
      list-style: none;
      margin-top: 20px;
    }

    .feature-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .feature-list li::before {
      content: '';
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      flex-shrink: 0;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-card);
      border-left: 4px solid var(--primary);
      transition: var(--transition);
    }

    .faq-question {
      font-weight: 700;
      font-size: 18px;
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
      color: var(--secondary);
    }

    .faq-question i {
      color: var(--primary);
      font-size: 20px;
    }

    .faq-answer {
      color: var(--gray-500);
      line-height: 1.6;
    }

    /* CTA */
    .cta-section {
      background: var(--secondary);
      text-align: center;
      padding: 80px 0;
    }

    .cta-section h2 {
      color: white;
      margin-bottom: 16px;
    }

    .cta-sub {
      color: rgba(255,255,255,0.8);
      font-size: 18px;
      margin-bottom: 32px;
    }

    /* 页脚 */
    .footer {
      background: var(--white);
      padding: 60px 0 20px;
      border-top: 1px solid var(--gray-100);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-brand .logo {
      margin-bottom: 16px;
    }

    .footer-desc {
      color: var(--gray-500);
      font-size: 14px;
    }

    .footer-col h4 {
      margin-bottom: 20px;
      font-size: 16px;
      color: var(--secondary);
    }

    .footer-col a {
      display: block;
      color: var(--gray-500);
      font-size: 14px;
      margin-bottom: 12px;
    }

    .footer-col a:hover {
      color: var(--primary);
    }

    .copyright {
      text-align: center;
      color: var(--text-muted);
      font-size: 13px;
      padding-top: 24px;
      border-top: 1px solid var(--gray-100);
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .advantages-grid { grid-template-columns: repeat(2, 1fr); }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      section { padding: 60px 0; }

      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }

      .nav-links.active {
        display: flex;
      }

      .hamburger {
        display: block;
      }

      .advantages-grid,
      .stats-grid,
      .faq-grid {
        grid-template-columns: 1fr;
      }

      .solution-row,
      .solution-row.reverse {
        flex-direction: column;
      }

      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }

      .hero-badges {
        flex-direction: column;
        align-items: center;
      }
    }

    @media (max-width: 520px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }