/* roulang page: index */
:root {
      --primary: #0B0E1A;
      --accent1: #6C5CE7;
      --accent2: #00E5FF;
      --bg-dark: #1A1F2E;
      --bg-light: #F5F6FA;
      --text-primary: #E8ECF1;
      --text-secondary: #6B7280;
      --card-bg: #FFFFFF;
      --border-light: #E5E7EB;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 32px rgba(108,92,231,0.12);
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: #0B0E1A;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container-main {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }
    @media (min-width: 1024px) {
      .container-main {
        padding-left: 32px;
        padding-right: 32px;
      }
    }
    /* 左侧导航桌面样式 */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: 80px;
      height: 100vh;
      background-color: var(--primary);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 24px 12px;
      z-index: 50;
      box-shadow: 2px 0 15px rgba(0,0,0,0.2);
    }
    .nav-logo img {
      width: 40px;
      height: 40px;
      object-fit: contain;
    }
    .nav-channels {
      display: flex;
      flex-direction: column;
      gap: 12px;
      align-items: center;
    }
    .nav-link {
      writing-mode: vertical-rl;
      text-orientation: mixed;
      font-size: 13px;
      font-weight: 500;
      color: #6B7280;
      text-decoration: none;
      padding: 8px 4px;
      border-radius: 8px;
      transition: color 0.2s, border-left 0.2s;
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: 0.5px;
    }
    .nav-link i {
      writing-mode: horizontal-tb;
      font-size: 14px;
      margin-bottom: 4px;
    }
    .nav-link:hover {
      color: var(--accent2);
    }
    .nav-link.active {
      color: var(--accent1);
      border-left: 3px solid var(--accent1);
      padding-left: 8px;
    }
    .nav-cta {
      background: linear-gradient(135deg, #6C5CE7 0%, #00E5FF 100%);
      color: white;
      border: none;
      padding: 8px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      writing-mode: vertical-rl;
      text-orientation: mixed;
      transition: 0.2s;
      letter-spacing: 0.5px;
      height: auto;
    }
    .nav-cta:hover {
      box-shadow: 0 0 15px rgba(108,92,231,0.5);
      transform: scale(1.02);
    }
    /* 移动端顶部导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background-color: var(--primary);
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 60;
      box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    }
    @media (max-width: 768px) {
      .side-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      .hero-section {
        margin-left: 0 !important;
        padding-top: 56px;
      }
      .main-content {
        margin-left: 0 !important;
      }
    }
    .hamburger {
      color: white;
      font-size: 24px;
      background: none;
      border: none;
      cursor: pointer;
    }
    .mobile-menu {
      position: fixed;
      top: 56px;
      left: 0;
      width: 100%;
      background: rgba(11,14,26,0.96);
      backdrop-filter: blur(8px);
      display: flex;
      flex-direction: column;
      padding: 24px;
      gap: 16px;
      z-index: 55;
      transform: translateY(-120%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.open {
      transform: translateY(0);
    }
    .mobile-menu a {
      color: #E8ECF1;
      font-size: 18px;
      text-decoration: none;
      padding: 12px 0;
      border-bottom: 1px solid #374151;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    /* Hero区 */
    .hero-section {
      margin-left: 80px;
      min-height: 100vh;
      display: flex;
      background: radial-gradient(ellipse at 30% 50%, #1A1F2E 0%, #0B0E1A 70%);
      position: relative;
      overflow: hidden;
    }
    .hero-stars::before {
      content: '';
      position: absolute;
      width: 100%;
      height: 100%;
      background: radial-gradient(1px 1px at 20% 30%, rgba(255,255,255,0.4), transparent),
                  radial-gradient(2px 2px at 70% 20%, rgba(255,255,255,0.5), transparent),
                  radial-gradient(2px 2px at 40% 70%, rgba(255,255,255,0.3), transparent),
                  radial-gradient(1px 1px at 80% 80%, rgba(255,255,255,0.6), transparent);
      background-size: 200px 200px;
      pointer-events: none;
    }
    .hero-content {
      display: flex;
      width: 100%;
      align-items: center;
    }
    .hero-text {
      flex: 1;
      padding: 40px;
      color: white;
      z-index: 2;
    }
    .hero-visual {
      flex: 1;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-visual img {
      max-width: 90%;
      height: auto;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
      filter: brightness(0.9);
    }
    .micro-data {
      display: flex;
      gap: 24px;
      margin-top: 20px;
    }
    .micro-item {
      font-size: 14px;
      color: #B0B8C9;
    }
    .btn-primary {
      background: linear-gradient(135deg, #6C5CE7 0%, #00E5FF 100%);
      color: white;
      padding: 14px 32px;
      border-radius: 8px;
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: 0.2s;
      display: inline-block;
      text-decoration: none;
    }
    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: 0 0 20px rgba(108,92,231,0.4);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--accent1);
      color: var(--accent1);
      padding: 14px 32px;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.2s;
      text-decoration: none;
    }
    .btn-secondary:hover {
      background: rgba(108,92,231,0.1);
    }
    .section-title h2 {
      font-size: 32px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 8px;
    }
    .subtitle-en {
      font-size: 14px;
      font-weight: 400;
      color: var(--accent2);
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }
    .card {
      background: white;
      border-radius: 16px;
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: 0.3s ease;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .faq-item {
      border-bottom: 1px solid #E5E7EB;
      padding: 16px 0;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F9FAFB;
      padding-left: 32px;
    }
    footer a {
      color: #B0B8C9;
      transition: color 0.2s;
    }
    footer a:hover {
      color: var(--accent2);
    }
    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero-text {
        padding: 20px;
      }
      .grid-2col {
        grid-template-columns: 1fr !important;
      }
    }