/* roulang page: index */
:root {
      --primary-red: #E63946;
      --primary-red-dark: #C1121F;
      --deep-ink: #1D3557;
      --warm-gold: #F4A261;
      --light-gray: #F8F9FA;
      --white: #FFFFFF;
      --border-light: #E9ECEF;
      --text-main: #1D3557;
      --text-body: #333333;
      --text-muted: #6C757D;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.12);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition-smooth: all 0.3s ease;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    }

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

    body {
      font-family: var(--font-stack);
      background-color: var(--light-gray);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      transition: var(--transition-smooth);
      height: 72px;
      display: flex;
      align-items: center;
    }

    .site-header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }

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

    .logo {
      display: flex;
      align-items: center;
      text-decoration: none;
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--deep-ink);
      letter-spacing: 0.5px;
    }

    .logo i {
      color: var(--primary-red);
      margin-right: 10px;
      font-size: 2rem;
    }

    .logo span {
      color: var(--primary-red);
      font-weight: 800;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }

    .nav-menu a {
      text-decoration: none;
      color: var(--text-main);
      font-weight: 500;
      font-size: 1rem;
      transition: var(--transition-smooth);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary-red);
      border-bottom-color: var(--primary-red);
    }

    .nav-cta {
      background: var(--primary-red);
      color: white !important;
      padding: 10px 24px !important;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border-bottom: none !important;
      transition: var(--transition-smooth);
    }

    .nav-cta:hover {
      background: var(--primary-red-dark);
      box-shadow: 0 6px 16px rgba(230, 57, 70, 0.4);
      color: white !important;
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--deep-ink);
      cursor: pointer;
    }

    /* 英雄区 */
    .hero {
      background: var(--white);
      padding: 140px 0 100px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid var(--border-light);
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-content {
      flex: 1 1 50%;
    }

    .hero-content h1 {
      font-size: 3rem;
      font-weight: 700;
      color: var(--deep-ink);
      line-height: 1.3;
      margin-bottom: 1.5rem;
    }

    .hero-content h1 span {
      color: var(--primary-red);
    }

    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-body);
      margin-bottom: 2.2rem;
      line-height: 1.8;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition-smooth);
      text-align: center;
      font-size: 1rem;
    }

    .btn-primary {
      background: var(--primary-red);
      color: white;
      border: 2px solid var(--primary-red);
    }

    .btn-primary:hover {
      background: var(--primary-red-dark);
      border-color: var(--primary-red-dark);
      box-shadow: 0 8px 20px rgba(230,57,70,0.4);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      color: var(--deep-ink);
      border: 2px solid var(--deep-ink);
    }

    .btn-outline:hover {
      background: var(--deep-ink);
      color: white;
      transform: translateY(-2px);
    }

    .hero-image {
      flex: 1 1 50%;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-hover);
    }

    .hero-image img {
      width: 100%;
      height: auto;
      display: block;
      object-fit: cover;
      aspect-ratio: 16 / 9;
    }

    /* 通用板块 */
    section {
      padding: 90px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }

    .section-title h2 {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--deep-ink);
      margin-bottom: 15px;
    }

    .section-title p {
      color: var(--text-muted);
      font-size: 1.1rem;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .feature-card {
      background: var(--white);
      padding: 36px 28px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: var(--transition-smooth);
    }

    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .feature-icon {
      font-size: 2.8rem;
      color: var(--primary-red);
      margin-bottom: 22px;
    }

    .feature-card h3 {
      font-size: 1.5rem;
      font-weight: 600;
      color: var(--deep-ink);
      margin-bottom: 15px;
    }

    .feature-card p {
      color: var(--text-body);
    }

    /* 产品服务 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .service-row:last-child {
      margin-bottom: 0;
    }

    .service-text {
      flex: 1;
    }

    .service-text h2 {
      font-size: 2rem;
      color: var(--deep-ink);
      margin-bottom: 22px;
    }

    .service-text p {
      margin-bottom: 24px;
      color: var(--text-body);
    }

    .check-list {
      list-style: none;
    }

    .check-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 500;
    }

    .check-list i {
      color: var(--primary-red);
    }

    .service-image {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .service-image img {
      width: 100%;
      display: block;
      object-fit: cover;
      aspect-ratio: 4/3;
    }

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

    /* 场景卡片 */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .scenario-card {
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      height: 280px;
    }

    .scenario-card img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .scenario-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      padding: 30px 20px;
      background: linear-gradient(transparent, rgba(29,53,87,0.9));
      color: white;
    }

    .scenario-overlay h3 {
      font-size: 1.5rem;
      margin-bottom: 8px;
    }

    /* 数据案例 */
    .stats-row {
      display: flex;
      justify-content: space-around;
      margin-bottom: 50px;
      flex-wrap: wrap;
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary-red);
    }

    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }

    .case-card {
      background: white;
      padding: 30px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    details {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      box-shadow: var(--shadow-card);
      padding: 18px 24px;
    }

    summary {
      font-weight: 600;
      color: var(--deep-ink);
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    summary i {
      color: var(--primary-red);
    }

    details p {
      margin-top: 14px;
      color: var(--text-body);
    }

    /* CTA */
    .cta-section {
      background: var(--deep-ink);
      text-align: center;
      color: white;
    }

    .cta-section h2 {
      font-size: 2.4rem;
      margin-bottom: 20px;
      color: white;
    }

    .btn-gold {
      background: var(--warm-gold);
      color: var(--deep-ink);
      border: none;
      font-weight: 700;
    }

    /* 页脚 */
    .footer {
      background: #0F1A2E;
      color: #B0C4DE;
      padding: 60px 0 30px;
    }

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

    .footer-logo {
      font-size: 1.8rem;
      color: white;
      margin-bottom: 16px;
    }

    .footer a {
      color: #B0C4DE;
      text-decoration: none;
    }

    .copyright {
      margin-top: 40px;
      text-align: center;
      border-top: 1px solid #2a3a4e;
      padding-top: 24px;
    }

    @media (max-width: 1024px) {
      .hero-grid, .service-row {
        flex-direction: column;
      }
      .features-grid, .scenarios-grid {
        grid-template-columns: 1fr 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 20px 30px rgba(0,0,0,0.1);
      }
      .nav-menu.active {
        display: flex;
      }
      .features-grid, .scenarios-grid, .cases-grid {
        grid-template-columns: 1fr;
      }
      .hero-content h1 {
        font-size: 2.2rem;
      }
    }