/* roulang page: index */
:root {
      --primary-deep: #1E2A38;
      --accent-orange: #F05423;
      --accent-orange-dark: #D9481A;
      --bg-warm: #F9F9F8;
      --white: #FFFFFF;
      --text-dark: #4A5568;
      --text-muted: #A0AEC0;
      --border-light: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 30px rgba(0,0,0,0.08);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --nav-width: 240px;
      --transition-base: all 0.3s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-dark);
      line-height: 1.7;
      margin: 0;
      display: flex;
      min-height: 100vh;
      overflow-x: hidden;
    }

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

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

    h1, h2, h3, h4 {
      font-weight: 600;
      line-height: 1.3;
      color: var(--primary-deep);
    }

    h1 {
      font-size: 3rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 2.25rem;
      font-weight: 600;
    }

    h3 {
      font-size: 1.5rem;
      font-weight: 600;
    }

    .text-muted-custom {
      color: var(--text-muted);
      font-size: 0.875rem;
      line-height: 1.6;
    }

    /* 左侧竖向导航 */
    #mainNav {
      width: var(--nav-width);
      height: 100vh;
      background-color: var(--primary-deep);
      color: white;
      position: fixed;
      left: 0;
      top: 0;
      display: flex;
      flex-direction: column;
      padding: 2rem 1.5rem;
      z-index: 1030;
      box-shadow: 2px 0 15px rgba(0,0,0,0.08);
    }

    .nav-brand {
      font-size: 1.6rem;
      font-weight: 700;
      letter-spacing: 1px;
      color: white;
      margin-bottom: 3rem;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .nav-brand i {
      color: var(--accent-orange);
      font-size: 2rem;
    }

    .nav-menu {
      list-style: none;
      padding: 0;
      margin: 0;
      flex: 1;
    }

    .nav-menu li {
      margin-bottom: 0.75rem;
    }

    .nav-menu a {
      color: rgba(255,255,255,0.75);
      font-weight: 500;
      padding: 0.6rem 1rem;
      border-radius: 8px;
      display: block;
      transition: var(--transition-base);
      font-size: 1rem;
    }

    .nav-menu a:hover, .nav-menu a.active {
      background-color: rgba(255,255,255,0.1);
      color: white;
      text-decoration: none;
    }

    .nav-cta {
      margin-top: auto;
      background-color: var(--accent-orange);
      color: white;
      text-align: center;
      padding: 0.8rem 1.2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-base);
      display: block;
      border: none;
      cursor: pointer;
    }
    .nav-cta:hover {
      background-color: var(--accent-orange-dark);
      color: white;
      box-shadow: 0 0 15px rgba(240,84,35,0.4);
    }

    /* 右侧内容区 */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      min-height: 100vh;
      background-color: var(--bg-warm);
    }

    /* 通用板块样式 */
    .section-padding {
      padding: 100px 0;
    }

    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    /* 卡片样式 */
    .card-custom {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 2rem;
      transition: var(--transition-base);
      border: none;
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .feature-icon {
      font-size: 2.2rem;
      color: var(--accent-orange);
      margin-bottom: 1.2rem;
    }

    /* 按钮 */
    .btn-primary-custom {
      background-color: var(--accent-orange);
      border: none;
      color: white;
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-base);
      display: inline-block;
      text-align: center;
    }
    .btn-primary-custom:hover {
      background-color: var(--accent-orange-dark);
      box-shadow: 0 8px 20px rgba(240,84,35,0.3);
      color: white;
    }

    .btn-outline-custom {
      background: transparent;
      border: 2px solid var(--accent-orange);
      color: var(--accent-orange);
      padding: 10px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-base);
      display: inline-block;
      text-align: center;
    }
    .btn-outline-custom:hover {
      background-color: #FFF0EB;
      color: var(--accent-orange);
    }

    /* Hero区域 */
    .hero-section {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      color: white;
      display: flex;
      align-items: center;
      min-height: 90vh;
    }
    .hero-overlay {
      background: rgba(30,42,56,0.8);
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .hero-content h1 {
      color: white;
    }
    .hero-content p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.9);
    }

    /* 场景交替布局 */
    .scenario-row {
      display: flex;
      align-items: center;
      margin-bottom: 4rem;
      gap: 3rem;
    }
    .scenario-img {
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    /* 数据看板 */
    .stat-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-orange);
      line-height: 1.2;
    }

    /* FAQ手风琴 */
    .accordion-button {
      font-weight: 600;
      background: transparent;
      box-shadow: none;
      border-bottom: 1px solid var(--border-light);
      color: var(--primary-deep);
      padding: 1.2rem 0;
    }
    .accordion-button:not(.collapsed) {
      color: var(--accent-orange);
      background: transparent;
      box-shadow: none;
    }
    .accordion-button::after {
      transition: transform 0.3s;
    }
    .accordion-body {
      padding: 1rem 0 1.5rem;
      color: var(--text-dark);
    }

    /* 移动端顶部导航 */
    .mobile-nav {
      display: none;
      background-color: var(--primary-deep);
      padding: 0.8rem 1.5rem;
      position: fixed;
      width: 100%;
      top: 0;
      z-index: 1040;
    }

    @media (max-width: 991px) {
      #mainNav {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 70px;
      }
      .mobile-nav {
        display: flex;
        justify-content: space-between;
        align-items: center;
      }
      .section-padding {
        padding: 60px 0;
      }
      h1 {
        font-size: 2.4rem;
      }
      h2 {
        font-size: 1.8rem;
      }
      .scenario-row {
        flex-direction: column;
      }
    }
    @media (max-width: 768px) {
      .container-custom {
        padding: 0 1.5rem;
      }
    }