/* roulang page: index */
/* ----- 设计变量与重置 ----- */
    :root {
      --color-bg-primary: #0A0E14;
      --color-bg-card: #141B22;
      --color-bg-input: #1E262E;
      --color-accent: #C8FF00;
      --color-accent-hover: #D4FF33;
      --color-danger: #D9042B;
      --color-text-primary: #FFFFFF;
      --color-text-secondary: #6C7A89;
      --color-success: #A3E635;
      --color-border: rgba(200, 255, 0, 0.15);
      --font-sans: 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
      --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
      --radius-sm: 4px;
      --radius-md: 8px;
      --shadow-card: 0 0 0 1px rgba(200, 255, 0, 0.08), 0 12px 28px rgba(0,0,0,0.7);
      --shadow-card-hover: 0 0 0 2px rgba(200, 255, 0, 0.35), 0 18px 36px rgba(0,0,0,0.85);
      --transition: 0.2s ease-out;
      --container-max: 1280px;
      --header-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
      background-color: var(--color-bg-primary);
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--color-bg-primary);
      color: var(--color-text-secondary);
      line-height: 1.6;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

    @media (max-width: 480px) {
      body {
        font-size: 15px;
      }
    }

    /* 容器 */
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }

    /* 排版 */
    h1, h2, h3, h4 {
      color: var(--color-text-primary);
      font-weight: 700;
    }

    h1 {
      font-size: 3.5rem;
      line-height: 1.2;
      font-weight: 700;
      letter-spacing: -0.02em;
    }

    h2 {
      font-size: 2.2rem;
      font-weight: 400;
      letter-spacing: 0.05em;
      margin-bottom: 1rem;
      text-align: center;
    }

    h3 {
      font-weight: 300;
      font-size: 1.3rem;
      color: var(--color-text-secondary);
    }

    h4 {
      font-weight: 500;
      font-size: 1.1rem;
      margin-bottom: 0.5rem;
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 2.5rem;
      }
      h2 {
        font-size: 1.9rem;
      }
    }

    p {
      margin-bottom: 1.5rem;
      max-width: 72ch;
    }

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

    a:hover {
      color: var(--color-accent-hover);
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: all var(--transition);
      text-decoration: none;
      border: 1px solid transparent;
      padding: 12px 28px;
      font-size: 1rem;
      letter-spacing: 0.03em;
    }

    .btn-primary {
      background: var(--color-accent);
      color: #0A0E14;
      border-color: var(--color-accent);
      font-weight: 700;
      box-shadow: 0 0 10px rgba(200, 255, 0, 0.2);
    }

    .btn-primary:hover {
      background: var(--color-accent-hover);
      border-color: var(--color-accent-hover);
      box-shadow: 0 0 22px rgba(200, 255, 0, 0.5);
      transform: scale(1.03);
      color: #0A0E14;
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--color-accent);
      color: var(--color-accent);
    }

    .btn-outline:hover {
      background: rgba(200, 255, 0, 0.08);
      border-color: var(--color-accent-hover);
      color: var(--color-accent-hover);
    }

    .btn-lg {
      padding: 16px 40px;
      font-size: 1.2rem;
      border-radius: var(--radius-sm);
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(10, 14, 20, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(200, 255, 0, 0.2);
      height: var(--header-height);
      display: flex;
      align-items: center;
    }

    .nav-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 1.9rem;
      font-weight: 700;
      color: var(--color-accent);
      letter-spacing: -0.5px;
      display: flex;
      align-items: baseline;
      gap: 6px;
      text-decoration: none;
    }

    .logo span {
      font-size: 1rem;
      font-weight: 400;
      color: var(--color-text-secondary);
      letter-spacing: 0.02em;
    }

    .nav-links {
      display: flex;
      gap: 2rem;
      list-style: none;
    }

    .nav-links a {
      color: var(--color-text-secondary);
      font-size: 0.95rem;
      font-weight: 500;
      letter-spacing: 0.03em;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--color-accent);
      border-bottom-color: var(--color-accent);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      flex-direction: column;
      gap: 5px;
      padding: 8px;
    }

    .menu-toggle span {
      display: block;
      width: 25px;
      height: 2px;
      background: var(--color-accent);
      transition: 0.2s;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: var(--color-bg-card);
        flex-direction: column;
        padding: 20px;
        gap: 1.2rem;
        border-bottom: 1px solid var(--color-accent);
      }

      .nav-links:target {
        display: flex;
      }

      .menu-toggle {
        display: flex;
      }

      #menu-toggle-checkbox {
        display: none;
      }

      /* 纯 CSS 汉堡菜单通过 :target 实现，但需要一个隐藏 checkbox 技巧。
         此处使用更简洁的方式：通过锚点 #menu-open 控制显示。
         在移动端，菜单按钮指向 #menu-open，菜单容器 id="menu-open" 作为目标。
      */
      .nav-links:target {
        display: flex;
      }
    }

    /* 首屏 Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      background: radial-gradient(circle at 30% 30%, rgba(200, 255, 0, 0.08) 0%, transparent 60%);
      overflow: hidden;
    }

    .hero::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: 
        linear-gradient(rgba(200, 255, 0, 0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(200, 255, 0, 0.06) 1px, transparent 1px);
      background-size: 60px 60px;
      pointer-events: none;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 750px;
      padding: 2rem 0;
    }

    .hero h1 {
      margin-bottom: 1.2rem;
    }

    .hero .subtitle {
      font-size: 1.3rem;
      font-weight: 300;
      color: var(--color-text-secondary);
      margin-bottom: 2.5rem;
    }

    .floating-numbers {
      position: absolute;
      right: 5%;
      bottom: 15%;
      font-family: var(--font-mono);
      font-size: 2rem;
      color: rgba(200, 255, 0, 0.15);
      display: flex;
      gap: 2rem;
      animation: pulseData 2s infinite alternate;
    }

    @keyframes pulseData {
      0% { opacity: 0.1; transform: translateY(0); }
      100% { opacity: 0.25; transform: translateY(-8px); }
    }

    /* 数据指标看板 */
    .metrics {
      background-color: var(--color-bg-card);
      padding: 4rem 0;
      border-top: 1px solid rgba(200,255,0,0.1);
    }

    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }

    .metric-item {
      padding: 1.2rem;
    }

    .metric-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--color-accent);
      line-height: 1.2;
    }

    .metric-label {
      color: var(--color-text-secondary);
      font-size: 0.9rem;
      margin-top: 0.5rem;
    }

    /* 服务卡片 */
    .services {
      padding: 5rem 0;
    }

    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 2.5rem;
    }

    .card {
      background: var(--color-bg-card);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
    }

    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }

    .card-icon {
      font-size: 2rem;
      color: var(--color-accent);
      margin-bottom: 1rem;
    }

    .card h3 {
      font-size: 1.5rem;
      font-weight: 500;
      color: white;
      margin-bottom: 0.8rem;
    }

    .card p {
      color: var(--color-text-secondary);
      margin-bottom: 1.8rem;
      flex: 1;
    }

    /* 对比区 */
    .comparison {
      padding: 4rem 0;
      background: var(--color-bg-card);
    }

    .compare-table {
      display: flex;
      gap: 2rem;
      margin-top: 2rem;
      flex-wrap: wrap;
    }

    .compare-col {
      flex: 1;
      background: var(--color-bg-primary);
      padding: 2rem;
      border-radius: var(--radius-md);
      border-left: 4px solid;
    }

    .compare-col.traditional {
      border-left-color: var(--color-danger);
    }

    .compare-col.bwin {
      border-left-color: var(--color-accent);
    }

    .compare-col h3 {
      margin-bottom: 1.5rem;
      font-size: 1.5rem;
    }

    .row {
      display: flex;
      justify-content: space-between;
      padding: 0.8rem 0;
      border-bottom: 1px solid rgba(255,255,255,0.05);
      font-family: var(--font-mono);
    }

    /* FAQ */
    .faq {
      padding: 5rem 0;
    }

    .faq-list {
      max-width: 800px;
      margin: 2rem auto;
    }

    details {
      background: var(--color-bg-card);
      border-radius: var(--radius-md);
      margin-bottom: 1rem;
      padding: 0 20px;
    }

    summary {
      padding: 18px 0;
      font-weight: 500;
      color: white;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    summary::-webkit-details-marker {
      display: none;
    }

    .answer {
      padding: 0 0 18px;
      color: var(--color-text-secondary);
      background: var(--color-bg-input);
      margin-top: 8px;
      padding: 16px;
      border-radius: var(--radius-sm);
    }

    /* 表单 */
    .contact {
      padding: 5rem 0;
      background: radial-gradient(circle at 50% 0%, rgba(200,255,0,0.1) 0%, transparent 60%);
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 1.2rem;
      max-width: 520px;
      margin: 2rem auto;
    }

    input, select {
      background: var(--color-bg-input);
      border: 1px solid var(--color-text-secondary);
      border-radius: var(--radius-sm);
      padding: 14px 18px;
      color: white;
      font-size: 1rem;
    }

    input:focus, select:focus {
      outline: none;
      border-color: var(--color-accent);
      box-shadow: 0 0 0 3px rgba(200,255,0,0.2);
    }

    /* 页脚 */
    .footer {
      background: var(--color-bg-card);
      border-top: 1px solid rgba(200,255,0,0.2);
      padding: 2rem 0;
      margin-top: auto;
    }

    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 1rem;
    }

    @media (max-width: 768px) {
      .metrics-grid { grid-template-columns: repeat(2,1fr); }
      .cards-grid { grid-template-columns: 1fr; }
      .compare-table { flex-direction: column; }
      .footer-content { flex-direction: column; text-align: center; }
    }

    @media (max-width: 480px) {
      .metrics-grid { grid-template-columns: 1fr; }
    }