/* roulang page: index */
:root {
      --color-primary: #1E3A8A;
      --color-primary-dark: #172554;
      --color-secondary: #0D9488;
      --color-secondary-hover: #0F766E;
      --color-bg-light: #F8FAFC;
      --color-bg-card: #FFFFFF;
      --color-bg-dark: #0F172A;
      --color-text-main: #0F172A;
      --color-text-muted: #334155;
      --color-text-light: #64748B;
      --color-border: #E2E8F0;
      --radius-lg: 12px;
      --radius-full: 9999px;
      --shadow-soft: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
      --shadow-hover: 0 12px 28px -4px rgba(15, 23, 42, 0.12), 0 4px 10px -2px rgba(15, 23, 42, 0.06);
    }

    * {
      box-sizing: border-box;
      scroll-behavior: smooth;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--color-text-main);
      background-color: var(--color-bg-light);
      line-height: 1.75;
      letter-spacing: -0.01em;
      margin: 0;
      padding: 0;
    }

    .custom-container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    .hero-bg {
      background: linear-gradient(135deg, rgba(15, 23, 42, 0.88) 0%, rgba(30, 58, 138, 0.82) 100%),
                  url('/assets/images/4de8fb0ba204f438.webp') center/cover no-repeat;
    }

    .dark-engine-bg {
      background: radial-gradient(circle at 50% 20%, rgba(30, 58, 138, 0.45) 0%, rgba(15, 23, 42, 1) 75%),
                  url('/assets/images/ac31f8e5672b8ef6.webp') center/cover no-repeat;
    }

    .card-transition {
      transition: transform 0.28s ease, box-shadow 0.28s ease, border-color 0.28s ease;
    }
    .card-transition:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(13, 148, 136, 0.35);
    }

    .btn-primary {
      background-color: var(--color-secondary);
      color: #ffffff;
      transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .btn-primary:hover {
      background-color: var(--color-secondary-hover);
      transform: scale(1.02);
      box-shadow: 0 4px 14px rgba(13, 148, 136, 0.35);
    }

    .btn-outline {
      border: 1px solid rgba(255, 255, 255, 0.3);
      color: #ffffff;
      transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .btn-outline:hover {
      background-color: rgba(255, 255, 255, 0.1);
      border-color: #ffffff;
      transform: scale(1.02);
    }

    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, opacity 0.3s ease-out;
      opacity: 0;
    }
    .faq-item.active .faq-content {
      max-height: 220px;
      opacity: 1;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
      color: var(--color-secondary);
    }

    .slider-pane {
      display: none;
      opacity: 0;
      transition: opacity 0.5s ease-in-out;
    }
    .slider-pane.active {
      display: block;
      opacity: 1;
    }