/* roulang page: index */
:root {
      --bs-body-bg: #F4F7FC;
      --bs-primary: #0A1F3F;
      --bs-primary-rgb: 10, 31, 63;
      --bs-secondary: #00C2FF;
      --bs-secondary-rgb: 0, 194, 255;
      --bs-dark: #0A1F3F;
      --bs-light: #F4F7FC;
      --bs-border-radius: 12px;
      --bs-card-shadow: 0 2px 16px rgba(10, 31, 63, 0.06);
      --brand-primary: #0A1F3F;
      --brand-secondary: #00C2FF;
      --brand-accent: #FF6B35;
      --text-body: #3A4A5C;
      --text-muted: #6B7B8D;
      --text-dark: #0A1F3F;
      --border-light: #D1D9E3;
      --card-bg: #FFFFFF;
      --hover-shadow: 0 8px 24px rgba(10, 31, 63, 0.12);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-mono: "Inter", "Roboto", "SF Mono", monospace;
      --spacing-section: 100px;
      --container-max: 1140px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bs-body-bg);
      color: var(--text-body);
      margin: 0;
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

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

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 覆盖Bootstrap默认 */
    .btn {
      border-radius: 8px;
      font-weight: 600;
      padding: 12px 28px;
      transition: all 0.25s ease;
      letter-spacing: 0.3px;
    }
    .btn-brand {
      background: var(--brand-secondary);
      border: none;
      color: white;
    }
    .btn-brand:hover {
      background: #0099CC;
      color: white;
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(0,194,255,0.3);
    }
    .btn-outline-brand {
      background: transparent;
      border: 1.5px solid var(--brand-primary);
      color: var(--brand-primary);
    }
    .btn-outline-brand:hover {
      background: var(--brand-primary);
      color: white;
      border-color: var(--brand-primary);
    }
    .card {
      border-radius: 12px;
      background: var(--card-bg);
      box-shadow: var(--bs-card-shadow);
      border: none;
      transition: all 0.3s ease;
    }
    .card:hover {
      box-shadow: var(--hover-shadow);
      transform: translateY(-4px);
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      color: var(--text-dark);
    }
    h2 {
      font-size: 32px;
      text-align: center;
      margin-bottom: 0.5rem;
      position: relative;
      letter-spacing: -0.3px;
    }
    .section-title-wrapper {
      text-align: center;
      margin-bottom: 3rem;
    }
    .section-title-wrapper h2::after {
      content: '';
      display: block;
      width: 50px;
      height: 4px;
      background: var(--brand-secondary);
      margin: 12px auto 0;
      border-radius: 2px;
    }

    /* 导航分屏布局 */
    .app-layout {
      display: flex;
      min-height: 100vh;
    }
    .sidebar-nav {
      width: 280px;
      background: rgba(10, 31, 63, 0.97);
      backdrop-filter: blur(8px);
      color: white;
      display: flex;
      flex-direction: column;
      padding: 2rem 1.5rem;
      position: fixed;
      top: 0;
      left: 0;
      height: 100vh;
      z-index: 1030;
      box-shadow: 4px 0 20px rgba(0,0,0,0.08);
    }
    .main-content {
      margin-left: 280px;
      width: calc(100% - 280px);
      background: var(--bs-body-bg);
    }
    .logo-area {
      font-size: 1.6rem;
      font-weight: 700;
      color: white;
      margin-bottom: 2.5rem;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-area span {
      color: var(--brand-secondary);
    }
    .nav-menu {
      list-style: none;
      padding: 0;
      margin: 0;
      flex: 1;
    }
    .nav-menu li {
      margin-bottom: 0.5rem;
    }
    .nav-menu a {
      display: block;
      padding: 10px 16px;
      color: rgba(255,255,255,0.8);
      border-radius: 8px;
      font-weight: 500;
      transition: all 0.2s;
      position: relative;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: white;
      background: rgba(255,255,255,0.08);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 4px;
      left: 16px;
      width: 0;
      height: 2px;
      background: var(--brand-secondary);
      transition: width 0.2s ease;
    }
    .nav-menu a:hover::after {
      width: 30px;
    }
    .mobile-header {
      display: none;
    }

    /* Hero */
    #hero {
      padding: 4rem 0 5rem;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 2.5rem;
      align-items: center;
    }
    .hero-title {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--brand-primary);
      letter-spacing: -0.5px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-body);
      margin: 1.2rem 0 2rem;
      max-width: 500px;
    }
    .trust-badge {
      margin-top: 1.8rem;
      font-size: 13px;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    /* 功能卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      padding: 2rem 1.5rem;
      border-radius: 12px;
      box-shadow: var(--bs-card-shadow);
      text-align: center;
      transition: 0.25s;
    }
    .feature-card:hover {
      box-shadow: var(--hover-shadow);
      transform: translateY(-5px);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--brand-secondary);
      margin-bottom: 1.2rem;
    }

    /* 场景 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 3rem;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-img {
      flex: 1;
      border-radius: 12px;
      overflow: hidden;
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: white;
      border-radius: 12px;
      padding: 1.8rem;
      box-shadow: 0 2px 14px rgba(0,0,0,0.04);
      border-top: 4px solid var(--brand-secondary);
    }
    .kpi-number {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--brand-accent);
      font-family: var(--font-mono);
    }

    /* 价格 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .pricing-card {
      background: white;
      border-radius: 16px;
      padding: 2rem;
      text-align: center;
      border: 1px solid #E1E8F0;
      transition: 0.2s;
    }
    .pricing-card.recommended {
      border: 2px solid var(--brand-secondary);
      background: #F0FAFF;
    }
    .price {
      font-size: 3rem;
      font-weight: 700;
      color: var(--brand-primary);
      font-family: var(--font-mono);
    }

    /* FAQ */
    .accordion-button {
      font-weight: 600;
      background: white;
      box-shadow: none;
    }
    .accordion-button:not(.collapsed) {
      background: #F4F7FC;
      color: var(--brand-primary);
    }

    /* CTA表单 */
    #contact {
      background: #FFFFFF;
      border-radius: 20px;
      padding: 3rem;
      box-shadow: 0 10px 30px rgba(0,0,0,0.04);
    }
    .form-control {
      border-radius: 8px;
      border: 1px solid #D1D9E3;
      padding: 12px 16px;
    }
    .form-control:focus {
      border-color: var(--brand-secondary);
      box-shadow: 0 0 0 3px rgba(0,194,255,0.15);
    }

    footer {
      background: #0A1F3F;
      color: #B0BECC;
      padding: 3rem 0 1.5rem;
      margin-top: 3rem;
    }
    footer a:hover {
      color: var(--brand-secondary);
    }

    @media (max-width: 992px) {
      .sidebar-nav {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        background: #0A1F3F;
        padding: 0.8rem 1.5rem;
        position: sticky;
        top: 0;
        z-index: 1040;
      }
      .mobile-logo {
        color: white;
        font-weight: 700;
        font-size: 1.3rem;
      }
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .cases-grid, .pricing-grid {
        grid-template-columns: 1fr;
      }
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .scenario-row {
        flex-direction: column;
      }
      .scenario-row.reverse {
        flex-direction: column;
      }
      h2 {
        font-size: 28px;
      }
      .hero-title {
        font-size: 32px;
      }
    }