/* roulang page: index */
:root {
      --bg-main: #0B0C0E;
      --bg-card: #15171B;
      --bg-card-alt: #1A1D23;
      --primary: #00FF9D;
      --primary-hover: #00E58D;
      --accent: #7928CA;
      --accent-glow: rgba(121, 40, 202, 0.35);
      --text-main: #F3F4F6;
      --text-muted: #8E96A4;
      --border-color: rgba(255, 255, 255, 0.08);
      --border-focus: rgba(0, 255, 157, 0.5);
      --font-code: "JetBrains Mono", "Fira Code", "SFMono-Regular", Consolas, monospace;
      --font-base: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, sans-serif;
    }

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

    body {
      background-color: var(--bg-main);
      color: var(--text-main);
      font-family: var(--font-base);
      font-size: 15px;
      line-height: 1.7;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: all 0.25s ease;
    }

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

    .mono {
      font-family: var(--font-code);
    }

    /* 顶部双行导航 */
    .top-bar {
      background-color: #07080A;
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
      font-size: 12px;
      color: var(--text-muted);
      padding: 6px 0;
    }
    .top-bar a:hover {
      color: var(--primary);
    }
    .status-indicator {
      display: inline-block;
      width: 7px;
      height: 7px;
      background-color: var(--primary);
      border-radius: 50%;
      box-shadow: 0 0 8px var(--primary);
      margin-right: 6px;
    }

    .main-navbar {
      background: rgba(11, 12, 14, 0.88);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border-bottom: 1px solid var(--border-color);
      position: sticky;
      top: 0;
      z-index: 1030;
      padding: 14px 0;
      transition: all 0.3s ease;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 18px;
      font-weight: 700;
      letter-spacing: -0.2px;
      color: var(--text-main);
    }
    .brand-icon {
      width: 30px;
      height: 30px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #000;
      font-weight: 900;
      font-size: 15px;
    }
    .nav-link {
      color: var(--text-muted);
      font-size: 14px;
      padding: 8px 14px !important;
      transition: color 0.2s;
    }
    .nav-link:hover, .nav-link:focus {
      color: var(--primary);
    }

    /* 统一按钮设计 */
    .btn-engine-primary {
      background-color: var(--primary);
      color: #050607;
      font-weight: 600;
      font-size: 14px;
      padding: 9px 20px;
      border-radius: 6px;
      border: 1px solid var(--primary);
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      min-height: 42px;
    }
    .btn-engine-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 0 20px rgba(0, 255, 157, 0.4);
      color: #000;
      transform: translateY(-1px);
    }
    .btn-engine-outline {
      background-color: transparent;
      color: var(--text-main);
      font-weight: 500;
      font-size: 14px;
      padding: 9px 20px;
      border-radius: 6px;
      border: 1px solid rgba(255, 255, 255, 0.2);
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 42px;
    }
    .btn-engine-outline:hover {
      border-color: var(--primary);
      color: var(--primary);
      background-color: rgba(0, 255, 157, 0.05);
      transform: translateY(-1px);
    }

    /* 板块通用规范 */
    .section-py {
      padding: 96px 0;
      position: relative;
    }
    .section-alt {
      background-color: #0F1014;
    }
    .section-dark {
      background-color: #050608;
    }
    .section-badge {
      display: inline-block;
      font-size: 12px;
      font-family: var(--font-code);
      text-transform: uppercase;
      padding: 4px 10px;
      border-radius: 4px;
      background: rgba(0, 255, 157, 0.1);
      color: var(--primary);
      border: 1px solid rgba(0, 255, 157, 0.25);
      margin-bottom: 16px;
      letter-spacing: 0.8px;
    }
    .section-title {
      font-size: 34px;
      font-weight: 700;
      line-height: 1.25;
      margin-bottom: 18px;
      color: #FFFFFF;
      letter-spacing: -0.5px;
    }
    .section-intro {
      font-size: 16px;
      color: var(--text-muted);
      max-width: 780px;
      margin-bottom: 50px;
      line-height: 1.8;
    }

    /* 卡片通用 */
    .engine-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: 6px;
      padding: 30px;
      transition: all 0.3s cubic-bezier(0.165, 0.84, 0.44, 1);
      height: 100%;
      position: relative;
      display: flex;
      flex-direction: column;
    }
    .engine-card:hover {
      transform: translateY(-4px);
      border-color: rgba(0, 255, 157, 0.35);
      box-shadow: 0 16px 36px rgba(0, 0, 0, 0.5), 0 0 24px rgba(0, 255, 157, 0.1);
    }
    .card-meta-code {
      font-family: var(--font-code);
      font-size: 11px;
      color: var(--primary);
      position: absolute;
      top: 20px;
      right: 20px;
      background: rgba(0, 255, 157, 0.08);
      padding: 2px 8px;
      border-radius: 3px;
    }

    /* 1. 首屏 Banner (#hero) */
    .hero-section {
      min-height: 84vh;
      display: flex;
      align-items: center;
      position: relative;
      background-position: center center;
      background-size: cover;
      background-repeat: no-repeat;
      padding: 80px 0 100px;
    }
    .hero-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(135deg, rgba(11, 12, 14, 0.96) 20%, rgba(11, 12, 14, 0.82) 65%, rgba(11, 12, 14, 0.94) 100%);
      pointer-events: none;
    }
    .hero-content {
      position: relative;
      z-index: 2;
    }
    .hero-h1 {
      font-size: 48px;
      font-weight: 800;
      line-height: 1.18;
      letter-spacing: -1px;
      margin-bottom: 24px;
      color: #FFFFFF;
    }
    .hero-h1 span {
      background: linear-gradient(120deg, #FFFFFF 30%, var(--primary) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-desc {
      font-size: 16px;
      color: #B5BDC9;
      line-height: 1.85;
      margin-bottom: 36px;
      max-width: 620px;
    }
    .hero-meta-panel {
      background: rgba(21, 23, 27, 0.85);
      border: 1px solid var(--border-color);
      border-radius: 8px;
      padding: 24px;
      backdrop-filter: blur(10px);
    }
    .hero-preview-img {
      border-radius: 6px;
      border: 1px solid var(--border-color);
      width: 100%;
      object-fit: cover;
      max-height: 420px;
    }

    /* 2. 痛点分析 (#pain-points) */
    .pain-card {
      background: #111317;
      border-left: 3px solid #E5484D;
      padding: 26px;
      border-radius: 4px;
      height: 100%;
    }
    .pain-num {
      font-family: var(--font-code);
      font-size: 13px;
      color: #E5484D;
      margin-bottom: 10px;
      display: block;
    }

    /* 3. 架构介绍 (#about) */
    .arch-specs {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
      margin-top: 24px;
    }
    .arch-spec-item {
      background: #121418;
      border: 1px solid var(--border-color);
      padding: 14px 18px;
      border-radius: 4px;
    }

    /* 5. 版本矩阵 (#products) */
    .pricing-card-featured {
      border: 1px solid var(--primary) !important;
      background: linear-gradient(180deg, #181C22 0%, #13151A 100%);
    }

    /* 6. 核心理念 (#philosophy) */
    .code-box {
      background: #000000;
      border: 1px solid #23272E;
      border-radius: 6px;
      padding: 24px;
      font-family: var(--font-code);
      font-size: 13px;
      color: #00FF9D;
      line-height: 1.7;
    }

    /* 8. 成果数据指标 (#metrics) */
    .metric-value {
      font-family: var(--font-code);
      font-size: 42px;
      font-weight: 700;
      color: #FFFFFF;
      line-height: 1;
      margin-bottom: 8px;
    }
    .metric-unit {
      color: var(--primary);
      font-size: 20px;
      font-weight: 400;
    }

    /* 12. FAQ (#faq) */
    .accordion-item {
      background-color: var(--bg-card);
      border: 1px solid var(--border-color);
      margin-bottom: 12px;
      border-radius: 6px !important;
      overflow: hidden;
    }
    .accordion-button {
      background-color: var(--bg-card);
      color: var(--text-main);
      font-weight: 600;
      font-size: 16px;
      padding: 20px 24px;
      box-shadow: none !important;
    }
    .accordion-button:not(.collapsed) {
      color: var(--primary);
      background-color: #171A21;
    }
    .accordion-button::after {
      filter: invert(1);
    }
    .accordion-body {
      background-color: #171A21;
      color: var(--text-muted);
      font-size: 15px;
      line-height: 1.8;
      padding: 20px 24px 26px;
    }

    /* 13. 行动呼吁 (#cta) */
    .cta-card {
      background: radial-gradient(circle at top right, rgba(121, 40, 202, 0.25), transparent 50%), #131519;
      border: 1px solid rgba(0, 255, 157, 0.2);
      border-radius: 8px;
      padding: 56px 40px;
      box-shadow: 0 20px 50px rgba(0, 0, 0, 0.7);
    }
    .form-control, .form-select {
      background-color: #0B0C0E;
      border: 1px solid var(--border-color);
      color: #FFFFFF;
      border-radius: 4px;
      padding: 12px 16px;
      font-size: 14px;
    }
    .form-control:focus, .form-select:focus {
      background-color: #0B0C0E;
      border-color: var(--primary);
      box-shadow: 0 0 10px rgba(0, 255, 157, 0.2);
      color: #FFFFFF;
    }

    /* 页脚 */
    footer {
      background-color: #060708;
      border-top: 1px solid var(--border-color);
      padding: 80px 0 36px;
      font-size: 14px;
      color: var(--text-muted);
    }
    .footer-col-title {
      font-size: 15px;
      font-weight: 600;
      color: #FFFFFF;
      margin-bottom: 20px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .footer-links {
      list-style: none;
      padding: 0;
      margin: 0;
    }
    .footer-links li {
      margin-bottom: 12px;
    }
    .footer-links a:hover {
      color: var(--primary);
    }
    .footer-bottom {
      margin-top: 60px;
      padding-top: 24px;
      border-top: 1px solid rgba(255, 255, 255, 0.05);
      font-size: 13px;
    }

    /* 响应式调整 */
    @media (max-width: 991.98px) {
      .hero-h1 {
        font-size: 38px;
      }
      .section-title {
        font-size: 28px;
      }
      .section-py {
        padding: 64px 0;
      }
      .cta-card {
        padding: 36px 20px;
      }
    }
    @media (max-width: 767.98px) {
      .hero-h1 {
        font-size: 30px;
      }
      .hero-desc {
        font-size: 14px;
      }
      .arch-specs {
        grid-template-columns: 1fr;
      }
      .metric-value {
        font-size: 34px;
      }
    }