/* roulang page: index */
:root {
      --bg-deep: #0F0F0F;
      --bg-card: #1A1A1F;
      --border-light: #2C2C33;
      --text-primary: #FFFFFF;
      --text-secondary: #B0B0BB;
      --text-muted: #6B6B75;
      --accent-green: #00E5A0;
      --accent-purple: #7B2FFF;
      --green-glow: rgba(0, 229, 160, 0.15);
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
      --transition-smooth: 0.3s cubic-bezier(0.23, 1, 0.32, 1);
      --font-mono: 'SF Mono', 'Roboto Mono', 'Inter', monospace;
    }

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

    body {
      font-family: 'Inter', "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 背景网格纹理 */
    .grid-bg {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: 
        linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
      z-index: 0;
    }

    section {
      position: relative;
      z-index: 1;
      padding: 100px 0;
    }

    h2 {
      font-size: 38px;
      font-weight: 600;
      letter-spacing: -0.02em;
      margin-bottom: 16px;
      line-height: 1.3;
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .section-subtitle {
      color: var(--text-secondary);
      font-size: 17px;
      margin-bottom: 48px;
      max-width: 600px;
    }

    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 50;
      background: rgba(15, 15, 15, 0.85);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--border-light);
      transition: background 0.25s;
    }

    .nav-bar.scrolled {
      background: rgba(10, 10, 10, 0.97);
      box-shadow: 0 4px 20px rgba(0,0,0,0.6);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    .logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      letter-spacing: -0.5px;
    }
    .logo-icon {
      color: var(--accent-green);
      font-size: 28px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      font-size: 15px;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: #fff;
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-green);
    }

    .btn-primary {
      background: var(--accent-green);
      color: #0F0F0F;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: all 0.25s ease;
      border: none;
      cursor: pointer;
      display: inline-block;
      box-shadow: 0 0 0 rgba(0,229,160,0);
    }
    .btn-primary:hover {
      background: #00FFB3;
      box-shadow: 0 0 20px rgba(0,229,160,0.5);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-green);
      color: var(--accent-green);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: 0.25s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(0,229,160,0.08);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      border-radius: 2px;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      padding-top: 80px;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-visual {
      flex: 1;
      height: 400px;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,160,0.08) 0%, transparent 60%);
      position: relative;
    }
    .hero h1 {
      font-size: 60px;
      font-weight: 700;
      line-height: 1.15;
      letter-spacing: -0.02em;
      margin-bottom: 24px;
    }
    .hero h1 .highlight {
      color: var(--accent-green);
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 480px;
      margin-bottom: 36px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 实时数据亮点 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .stat-card {
      background: transparent;
      padding: 32px 20px;
      border-bottom: 2px solid var(--accent-green);
      transition: transform 0.25s;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-green);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-secondary);
      margin-top: 8px;
      font-size: 16px;
    }

    /* 卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .service-card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: all var(--transition-smooth);
      box-shadow: var(--shadow-card);
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 8px 40px var(--green-glow);
    }
    .card-icon {
      font-size: 36px;
      color: var(--accent-green);
      margin-bottom: 20px;
    }
    .text-link {
      color: var(--accent-green);
      text-decoration: none;
      font-weight: 500;
      margin-top: 16px;
      display: inline-block;
    }

    /* 案例区 */
    .case-row {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-bottom: 80px;
    }
    .case-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: 0 12px 30px rgba(0,0,0,0.5);
    }
    .case-img img {
      width: 100%;
      display: block;
      transition: filter 0.3s;
    }
    .case-img:hover img {
      filter: saturate(1.2);
    }
    .case-text {
      flex: 1;
    }

    /* 步骤 */
    .steps {
      display: flex;
      justify-content: space-between;
    }
    .step-item {
      text-align: center;
      flex: 1;
    }
    .step-circle {
      width: 56px;
      height: 56px;
      background: var(--accent-green);
      color: #0F0F0F;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 24px;
      margin: 0 auto 20px;
    }

    /* FAQ */
    .faq-item {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 28px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
      padding: 0 28px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    .cta-banner {
      background: #1A1A1F;
      text-align: center;
      padding: 80px 0;
      border-radius: 24px;
    }

    footer {
      background: #0A0A0D;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .cards-grid { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-content { flex-direction: column; }
      .hero h1 { font-size: 40px; }
      .cards-grid, .stats-grid { grid-template-columns: 1fr; }
      .case-row { flex-direction: column; }
      .steps { flex-direction: column; gap: 30px; }
      .footer-grid { grid-template-columns: 1fr; }
    }