/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --primary-deep: #0B1A2F;
      --accent-gold: #D4A843;
      --bg-gradient: linear-gradient(135deg, #0A111F 0%, #132238 100%);
      --surface-glass: rgba(255,255,255,0.04);
      --border-glass: rgba(255,255,255,0.08);
      --text-body: #E0E6F0;
      --text-heading: #FFFFFF;
      --text-muted: #8899B4;
      --glow-gold: 0 0 20px rgba(212,168,67,0.5);
      --glow-gold-hover: 0 0 32px rgba(212,168,67,0.8);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 8px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-hover: 0 12px 40px rgba(0,0,0,0.6);
      --max-width: 1280px;
      --spacing-section: 120px;
      --spacing-mobile: 80px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      background: #0A111F;
    }

    body {
      font-family: var(--font-sans);
      background: var(--bg-gradient);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 1rem;
      min-height: 100vh;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

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

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

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

    /* 导航 - 沉浸式玻璃效果 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10,17,31,0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.06);
      transition: background 0.3s;
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--text-heading);
      letter-spacing: -0.01em;
    }

    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--accent-gold);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 2L15 9H22L16 14L18 21L12 16.5L6 21L8 14L2 9H9L12 2Z"/></svg>') center/contain no-repeat;
      -webkit-mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 2L15 9H22L16 14L18 21L12 16.5L6 21L8 14L2 9H9L12 2Z"/></svg>') center/contain no-repeat;
      background-color: var(--accent-gold);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-link {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-muted);
      transition: color 0.2s;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--text-heading);
    }

    .btn-primary {
      background: var(--accent-gold);
      color: #0B1A2F;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      box-shadow: var(--glow-gold);
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      border: none;
      letter-spacing: 0.3px;
    }

    .btn-primary:hover {
      box-shadow: var(--glow-gold-hover);
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      color: var(--accent-gold);
      border: 1px solid var(--accent-gold);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: all 0.25s;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
    }

    .btn-outline:hover {
      background: rgba(212,168,67,0.1);
    }

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

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-heading);
      border-radius: 2px;
      transition: all 0.3s;
    }

    /* Hero */
    .hero {
      padding: 160px 0 100px;
      display: flex;
      align-items: center;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--text-heading);
      margin-bottom: 20px;
      line-height: 1.15;
    }

    .hero-highlight {
      color: var(--accent-gold);
    }

    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }

    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .trust-badge {
      display: flex;
      gap: 32px;
      color: var(--text-muted);
      font-size: 0.9rem;
    }

    .trust-badge span {
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .hero-visual {
      position: relative;
    }

    .hero-img {
      width: 100%;
      border-radius: 24px;
      box-shadow: var(--shadow-card);
    }

    .glass-overlay {
      position: absolute;
      bottom: 20px;
      left: 20px;
      right: 20px;
      background: var(--surface-glass);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--border-glass);
      border-radius: 16px;
      padding: 20px;
      color: var(--text-heading);
    }

    /* 板块标题 */
    .section {
      padding: var(--spacing-section) 0;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-heading);
      margin-bottom: 16px;
    }

    .section-sub {
      color: var(--text-muted);
      max-width: 600px;
      margin-bottom: 48px;
    }

    /* 核心优势 - 非对称布局 */
    .advantage-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .advantage-text h3 {
      font-size: 1.5rem;
      color: var(--text-heading);
      margin-bottom: 12px;
    }

    .advantage-img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }

    /* 功能标签切换 */
    .tab-nav {
      display: flex;
      gap: 24px;
      border-bottom: 1px solid var(--border-glass);
      margin-bottom: 32px;
      overflow-x: auto;
    }

    .tab-btn {
      background: transparent;
      color: var(--text-muted);
      font-weight: 600;
      padding: 12px 4px;
      border-bottom: 2px solid transparent;
      cursor: pointer;
      transition: 0.2s;
      white-space: nowrap;
    }

    .tab-btn.active {
      color: var(--accent-gold);
      border-bottom-color: var(--accent-gold);
    }

    .feature-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px,1fr));
      gap: 24px;
    }

    .feature-card {
      background: var(--surface-glass);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: all 0.3s;
    }

    .feature-card:hover {
      border-color: var(--accent-gold);
      box-shadow: 0 0 20px rgba(212,168,67,0.2);
    }

    .feature-icon {
      font-size: 2rem;
      color: var(--accent-gold);
      margin-bottom: 16px;
    }

    /* 场景卡片 */
    .scene-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 12px;
    }

    .scene-card {
      min-width: 280px;
      background: var(--surface-glass);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      overflow: hidden;
      transition: transform 0.2s;
    }

    .scene-card:hover {
      transform: scale(1.02);
    }

    .scene-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
    }

    .scene-info {
      padding: 20px;
    }

    /* 数据墙 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
      margin-bottom: 40px;
    }

    .stat-item {
      background: var(--surface-glass);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      padding: 32px;
      text-align: center;
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--accent-gold);
    }

    /* FAQ */
    .faq-item {
      background: var(--surface-glass);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      overflow: hidden;
    }

    .faq-question {
      width: 100%;
      background: transparent;
      color: var(--text-heading);
      font-weight: 600;
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      border: none;
      font-size: 1.05rem;
      text-align: left;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
      color: var(--text-muted);
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA 尾板 */
    .cta-dark {
      background: linear-gradient(135deg, #0B1A2F, #0A111F);
      text-align: center;
      padding: 100px 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding: 48px 0;
    }

    .copyright {
      border-top: 1px solid var(--border-glass);
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
      color: var(--text-muted);
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .hero-grid, .advantage-row {
        grid-template-columns: 1fr;
      }
      .stats-grid {
        grid-template-columns: repeat(2,1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10,17,31,0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 32px;
      }
      .nav-menu.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .section {
        padding: var(--spacing-mobile) 0;
      }
      .stats-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }