/* roulang page: index */
:root {
      --primary: #5B4CF0;
      --primary-glow: rgba(91, 76, 240, 0.6);
      --accent: #00F0C8;
      --accent-glow: rgba(0, 240, 200, 0.35);
      --bg-deep: #0A0E17;
      --bg-container: rgba(18, 22, 33, 0.8);
      --bg-card: rgba(18, 22, 33, 0.6);
      --border-light: rgba(91, 76, 240, 0.2);
      --border-glow: rgba(0, 240, 200, 0.55);
      --text-primary: #FFFFFF;
      --text-secondary: #B0C0D0;
      --text-muted: #7A889C;
      --radius-lg: 24px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --radius-btn: 50px;
      --shadow-card: 0 20px 40px rgba(0, 0, 0, 0.6);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "Inter", "SF Pro Display", system-ui, -apple-system;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.7;
      font-weight: 400;
      overflow-x: hidden;
    }

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

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 80px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 40px;
      background: transparent;
      z-index: 1000;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      backdrop-filter: blur(0px);
    }

    .navbar.scrolled {
      background: rgba(10, 14, 23, 0.9);
      backdrop-filter: blur(20px);
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
      border-bottom: 1px solid var(--border-light);
    }

    .logo {
      font-family: var(--font-mono);
      font-weight: 700;
      font-size: 24px;
      letter-spacing: 2px;
      background: linear-gradient(135deg, #FFFFFF 0%, #D0E0FF 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      filter: drop-shadow(0 0 8px rgba(91,76,240,0.5));
    }

    .logo-icon {
      font-size: 28px;
      filter: drop-shadow(0 0 6px var(--accent));
    }

    .nav-links {
      display: flex;
      gap: 36px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      text-decoration: none;
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 16px;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      box-shadow: 0 0 12px var(--accent-glow);
      transition: width 0.3s ease;
    }

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

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      gap: 5px;
      background: none;
      border: none;
    }

    .hamburger span {
      width: 28px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .navbar {
        height: 64px;
        padding: 0 24px;
      }
      .logo {
        font-size: 20px;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      background: radial-gradient(circle at 20% 30%, rgba(91,76,240,0.18) 0%, transparent 45%),
                  radial-gradient(circle at 80% 70%, rgba(0,240,200,0.12) 0%, transparent 55%);
      padding: 120px 32px 80px;
      overflow: hidden;
    }

    .hero-content {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      width: 100%;
      gap: 40px;
    }

    .hero-text {
      flex: 1 1 500px;
    }

    .hero h1 {
      font-size: 56px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 24px;
      background: linear-gradient(to right, #fff, #D6E0FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 550px;
    }

    .button-group {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, #5B4CF0, #00F0C8);
      color: #0A0E17;
      font-weight: 700;
      border-radius: 50px;
      padding: 16px 40px;
      border: none;
      font-size: 16px;
      cursor: pointer;
      box-shadow: 0 0 30px rgba(0,240,200,0.5);
      transition: all 0.3s ease;
      text-decoration: none;
      display: inline-block;
    }

    .btn-primary:hover {
      transform: translateY(-3px);
      box-shadow: 0 0 40px rgba(0,240,200,0.8);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent);
      color: var(--accent);
      font-weight: 600;
      border-radius: 50px;
      padding: 16px 36px;
      transition: all 0.3s;
      text-decoration: none;
    }

    .btn-outline:hover {
      background: rgba(0,240,200,0.1);
      box-shadow: 0 0 20px rgba(0,240,200,0.3);
    }

    .hero-stats {
      display: flex;
      gap: 60px;
      margin-top: 50px;
    }

    .stat h3 {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      font-family: var(--font-mono);
    }

    .hero-visual {
      flex: 1 1 400px;
      position: relative;
    }

    .hero-visual img {
      width: 100%;
      border-radius: 32px;
      box-shadow: 0 0 80px rgba(91,76,240,0.5);
    }

    @media (max-width: 768px) {
      .hero h1 {
        font-size: 36px;
      }
      .stat h3 {
        font-size: 36px;
      }
    }

    /* 通用区块 */
    section {
      padding: 120px 0;
    }

    .section-title {
      font-size: 40px;
      font-weight: 700;
      margin-bottom: 60px;
      text-align: center;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 32px;
    }

    .glass-card {
      background: rgba(18, 22, 33, 0.6);
      backdrop-filter: blur(20px);
      border: 1px solid rgba(91, 76, 240, 0.2);
      border-radius: 20px;
      padding: 36px;
      box-shadow: 0 8px 32px rgba(0,0,0,0.4);
    }

    /* 核心优势错层 */
    .advantage-layout {
      display: flex;
      gap: 36px;
      flex-wrap: wrap;
    }

    .large-card {
      flex: 2;
      min-width: 320px;
    }

    .small-stack {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 28px;
      min-width: 280px;
    }

    /* 功能矩阵 */
    .feature-row {
      display: flex;
      gap: 50px;
      align-items: center;
      margin-bottom: 100px;
    }

    .feature-row.reverse {
      flex-direction: row-reverse;
    }

    .feature-img img {
      width: 100%;
      border-radius: 20px;
    }

    .tag {
      background: rgba(91,76,240,0.3);
      color: white;
      padding: 6px 18px;
      border-radius: 30px;
      font-size: 14px;
      margin-right: 8px;
    }

    /* FAQ */
    .faq-item {
      background: rgba(18,22,33,0.8);
      margin-bottom: 12px;
      border-radius: 14px;
      overflow: hidden;
    }

    .faq-question {
      padding: 24px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }

    .faq-answer {
      padding: 0 24px 24px;
      display: none;
      border-left: 3px solid var(--accent);
      margin-left: 10px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .hero-stats {
        gap: 24px;
      }
    }