/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #7B2FF7;
      --primary-dark: #6918E0;
      --accent: #00E5FF;
      --deep-bg: #0D0221;
      --deep-bg2: #1A0533;
      --light-bg: #F8F6FC;
      --white: #FFFFFF;
      --text-dark: #1E1B2E;
      --text-gray: #5A5560;
      --text-light: #B8B0C8;
      --border-light: #E8E4F0;
      --card-shadow: 0 4px 20px rgba(123,47,247,0.08);
      --card-hover-shadow: 0 12px 32px rgba(123,47,247,0.18);
      --radius-lg: 20px;
      --radius-md: 14px;
      --radius-sm: 10px;
      --transition: 0.3s ease;
      --font-mono: 'JetBrains Mono', 'Courier New', monospace;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--light-bg);
      color: var(--text-dark);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, textarea {
      font-family: inherit;
      outline: none;
    }

    /* 容器 */
    .container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 板块通用间距 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
      html {
        font-size: 15px;
      }
    }

    /* ----- 沉浸式导航 ----- */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 999;
      background: linear-gradient(180deg, rgba(13,2,33,0.9) 0%, rgba(13,2,33,0.6) 80%, rgba(13,2,33,0.1) 100%);
      backdrop-filter: blur(12px);
      transition: background 0.4s, backdrop-filter 0.4s;
    }
    #header.scrolled {
      background: rgba(13,2,33,0.92);
      backdrop-filter: blur(16px);
      box-shadow: 0 8px 24px rgba(0,0,0,0.3);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--white);
      letter-spacing: 1px;
      background: linear-gradient(135deg, #fff 0%, #e0c4ff 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      color: rgba(255,255,255,0.75);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
      border-radius: 2px;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--white);
    }
    .nav-links a:hover::after, .nav-links a.active::after {
      width: 100%;
    }
    .btn-nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 0.9rem;
      box-shadow: 0 4px 12px rgba(123,47,247,0.5);
      transition: background var(--transition), box-shadow var(--transition);
      margin-left: 1rem;
    }
    .btn-nav-cta:hover {
      background: var(--primary-dark);
      box-shadow: 0 0 24px rgba(123,47,247,0.8);
    }
    /* 汉堡菜单 */
    .menu-toggle {
      display: none;
      font-size: 1.8rem;
      color: white;
      cursor: pointer;
    }
    @media (max-width: 1024px) {
      .nav-links {
        gap: 1.5rem;
      }
    }
    @media (max-width: 768px) {
      .menu-toggle {
        display: block;
      }
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 300px;
        height: 100vh;
        background: rgba(13,2,33,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: 2rem;
        transition: right 0.4s ease;
        padding: 2rem;
        box-shadow: -8px 0 30px rgba(0,0,0,0.5);
      }
      .nav-links.active {
        right: 0;
      }
      .btn-nav-cta {
        margin-left: 0;
        width: 100%;
        text-align: center;
      }
    }

    /* ----- Hero 首屏 ----- */
    #hero {
      background: linear-gradient(135deg, #0D0221 0%, #1A0533 70%, #220840 100%);
      color: white;
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 3.2rem;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      background: linear-gradient(to right, #fff, #e6d5ff);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-sub {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.5rem;
      font-weight: 400;
    }
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 36px;
      border-radius: 50px;
      font-weight: 700;
      font-size: 1rem;
      border: none;
      cursor: pointer;
      transition: all var(--transition);
      box-shadow: 0 8px 24px rgba(123,47,247,0.4);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 0 28px rgba(123,47,247,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      padding: 12px 34px;
      border-radius: 50px;
      font-weight: 700;
      font-size: 1rem;
      transition: all var(--transition);
      cursor: pointer;
    }
    .btn-outline:hover {
      background: var(--accent);
      color: var(--deep-bg);
      box-shadow: 0 0 22px rgba(0,229,255,0.5);
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: var(--radius-lg);
      min-height: 380px;
      box-shadow: 0 20px 40px rgba(123,47,247,0.3);
      border: 1px solid rgba(255,255,255,0.1);
    }
    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-image {
        min-height: 280px;
        order: -1;
      }
      .hero-buttons {
        justify-content: center;
      }
      .hero-content h1 {
        font-size: 2.4rem;
      }
    }

    /* ----- 数据看板 metrics ----- */
    #metrics {
      background: #0D0221;
      color: white;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .metric-card {
      background: rgba(255,255,255,0.04);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: var(--radius-lg);
      padding: 2rem 1.5rem;
      text-align: center;
      transition: all var(--transition);
    }
    .metric-card:hover {
      border-color: var(--accent);
      box-shadow: 0 8px 28px rgba(0,229,255,0.15);
    }
    .metric-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.2;
    }
    .metric-label {
      margin-top: 0.5rem;
      font-size: 0.95rem;
      color: #ccc;
    }
    @media (max-width: 768px) {
      .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    /* ----- 服务矩阵 ----- */
    #services {
      background: var(--light-bg);
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--text-dark);
    }
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 3rem;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      box-shadow: var(--card-hover-shadow);
      transform: translateY(-6px);
    }
    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .service-body {
      padding: 28px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .service-body h3 {
      font-size: 1.5rem;
      margin-bottom: 0.8rem;
    }
    .service-body p {
      color: var(--text-gray);
      font-size: 1rem;
      margin-bottom: 1.5rem;
      flex: 1;
    }
    .text-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 5px;
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 对比区块 ----- */
    #compare {
      background: white;
    }
    .compare-wrapper {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      gap: 1.5rem;
      align-items: center;
    }
    .compare-card {
      background: #f4f2f9;
      border-radius: var(--radius-lg);
      padding: 2.2rem;
      border: 1px solid var(--border-light);
    }
    .compare-card.highlight {
      background: white;
      border: 2px solid var(--primary);
      box-shadow: 0 0 28px rgba(123,47,247,0.2);
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 1.2rem 0;
    }
    .vs-badge {
      font-size: 2rem;
      font-weight: 800;
      color: var(--primary);
    }
    @media (max-width: 768px) {
      .compare-wrapper {
        grid-template-columns: 1fr;
      }
      .vs-badge {
        text-align: center;
      }
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      border: 1px solid var(--border-light);
      transition: all var(--transition);
    }
    .faq-question {
      padding: 20px 28px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 28px 20px;
      display: none;
      color: var(--text-gray);
    }
    .faq-item.active {
      border-color: var(--primary);
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 表单 */
    #cta {
      background: linear-gradient(135deg, #0D0221, #2a0a4a);
    }
    .cta-card {
      background: white;
      border-radius: 30px;
      padding: 3rem;
      max-width: 680px;
      margin: 0 auto;
      box-shadow: 0 30px 50px rgba(0,0,0,0.5);
    }
    .form-input {
      width: 100%;
      padding: 14px;
      margin: 12px 0;
      border: 1px solid #ddd;
      border-radius: 12px;
    }
    .btn-submit {
      background: var(--primary);
      color: white;
      border: none;
      padding: 16px;
      width: 100%;
      border-radius: 50px;
      font-weight: 700;
      margin-top: 10px;
    }

    footer {
      background: #0D0221;
      color: #ccc;
      padding: 50px 0 30px;
    }