/* roulang page: index */
:root {
      --primary-purple: #6C3CEC;
      --deep-charcoal: #1E1E24;
      --accent-orange: #FF6B35;
      --cold-gray: #F4F4F7;
      --white: #FFFFFF;
      --text-main: #1E1E24;
      --text-secondary: #666666;
      --text-muted: #999999;
      --border-light: #EEEEEE;
      --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 12px 32px rgba(108, 60, 236, 0.15);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: 0.25s ease-in-out;
      --font-stack: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    }

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

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

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

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

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 品牌导航行 */
    .brand-nav {
      background: var(--white);
      height: 64px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid var(--border-light);
      position: sticky;
      top: 0;
      z-index: 1020;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }
    .brand-nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: var(--deep-charcoal);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--primary-purple);
      font-size: 28px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-purple);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-purple);
      transition: width 0.2s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--deep-charcoal);
    }

    /* 频道导航行 */
    .channel-nav {
      background: var(--cold-gray);
      height: 44px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid var(--border-light);
      position: sticky;
      top: 64px;
      z-index: 1019;
    }
    .channel-tags {
      display: flex;
      gap: 32px;
      overflow-x: auto;
      white-space: nowrap;
      padding-bottom: 2px;
    }
    .channel-tags a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-secondary);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
    }
    .channel-tags a:hover,
    .channel-tags a.active {
      color: var(--primary-purple);
      border-bottom-color: var(--primary-purple);
    }

    /* Hero */
    #hero {
      background: linear-gradient(135deg, #1E1E24 0%, #2A2A35 100%);
      color: white;
      padding: 80px 0 60px;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 48px;
      font-weight: 900;
      line-height: 1.2;
      margin-bottom: 24px;
    }
    .hero-left h1 span {
      color: var(--accent-orange);
    }
    .hero-sub {
      font-size: 18px;
      opacity: 0.85;
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-cta {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary-custom {
      background: var(--primary-purple);
      color: white;
      border: none;
      padding: 12px 32px;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.2s;
      display: inline-block;
    }
    .btn-primary-custom:hover {
      background: #5A2FD0;
      transform: translateY(-2px);
      color: white;
    }
    .btn-outline-custom {
      border: 1.5px solid white;
      color: white;
      padding: 12px 32px;
      border-radius: 8px;
      font-weight: 600;
      background: transparent;
      transition: 0.2s;
    }
    .btn-outline-custom:hover {
      background: white;
      color: var(--deep-charcoal);
    }
    .hero-right img {
      border-radius: var(--radius-md);
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .scroll-hint {
      text-align: center;
      margin-top: 40px;
      opacity: 0.6;
      font-size: 24px;
    }

    /* 通用区块 */
    section {
      padding: 100px 0;
    }
    .section-label {
      font-size: 14px;
      letter-spacing: 1px;
      color: var(--primary-purple);
      font-weight: 600;
      margin-bottom: 12px;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    /* 指标看板 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 32px;
    }
    .metric-card {
      background: white;
      padding: 28px;
      border-radius: var(--radius-sm);
      box-shadow: var(--shadow-card);
      text-align: left;
    }
    .metric-number {
      font-size: 42px;
      font-weight: 800;
      color: var(--primary-purple);
      margin-bottom: 8px;
    }
    .metric-label {
      font-size: 14px;
      color: var(--text-secondary);
    }
    .trend-up {
      color: #2ecc71;
      margin-left: 6px;
    }

    /* 服务矩阵 2x3 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 32px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: 0.3s;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 160px;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .service-img::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 60px;
      background: linear-gradient(transparent, #1E1E24);
    }
    .service-content {
      padding: 24px 28px 28px;
    }
    .service-title {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
      position: relative;
    }
    .service-title::after {
      content: '';
      display: block;
      width: 32px;
      height: 4px;
      background: var(--primary-purple);
      margin-top: 8px;
      border-radius: 2px;
    }
    .service-desc {
      font-size: 14px;
      color: #777;
      margin: 16px 0;
    }
    .service-link {
      color: var(--primary-purple);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 对比区 */
    .compare-wrapper {
      display: flex;
      align-items: stretch;
      gap: 0;
      margin-top: 40px;
    }
    .compare-card {
      flex: 1;
      padding: 40px;
      border-radius: var(--radius-md);
    }
    .compare-traditional {
      background: var(--cold-gray);
      color: var(--text-muted);
    }
    .compare-yijijing {
      background: linear-gradient(135deg, #6C3CEC, #8B5CF6);
      color: white;
    }
    .vs-divider {
      background: white;
      width: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 20px;
      color: var(--deep-charcoal);
      border-radius: 50%;
      margin: 0 -24px;
      z-index: 2;
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
      height: 48px;
      align-self: center;
    }
    .compare-list {
      list-style: none;
      margin-top: 20px;
    }
    .compare-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    /* FAQ */
    .accordion-custom .accordion-button {
      background: white;
      font-weight: 600;
      font-size: 18px;
      box-shadow: none;
      border-bottom: 1px solid #eee;
      padding: 20px 0;
    }
    .accordion-custom .accordion-button:not(.collapsed) {
      color: var(--primary-purple);
      background: transparent;
      box-shadow: none;
    }
    .accordion-custom .accordion-body {
      padding: 20px 0 24px;
      color: #555;
    }

    /* 表单区块 */
    .contact-bar {
      background: var(--deep-charcoal);
      color: white;
      padding: 60px 0;
    }
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .input-line {
      background: transparent;
      border: none;
      border-bottom: 2px solid #ddd;
      border-radius: 0;
      padding: 12px 0;
      color: white;
      width: 100%;
      margin-bottom: 24px;
    }
    .input-line:focus {
      outline: none;
      border-bottom-color: var(--primary-purple);
    }
    .btn-orange {
      background: var(--accent-orange);
      border: none;
      padding: 14px 28px;
      border-radius: 8px;
      font-weight: 600;
      width: 100%;
      transition: 0.2s;
    }
    .btn-orange:hover {
      background: #e65a2c;
    }

    /* 页脚 */
    footer {
      background: var(--deep-charcoal);
      color: #aaa;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-title {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .footer-links a {
      display: block;
      color: #aaa;
      margin-bottom: 8px;
    }
    .copyright {
      border-top: 1px solid #333;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }

    @media (max-width: 1024px) {
      .hero-grid, .contact-grid {
        grid-template-columns: 1fr;
      }
      .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .compare-wrapper {
        flex-direction: column;
      }
      .vs-divider {
        margin: 16px auto;
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        background: white;
        width: 100%;
        box-shadow: 0 8px 20px rgba(0,0,0,0.1);
        padding: 20px;
      }
      .nav-links.show {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .channel-tags {
        gap: 20px;
      }
      .metrics-grid, .services-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }