/* roulang page: index */
:root {
      --bg-deep: #0B001A;
      --bg-card: rgba(20, 5, 40, 0.75);
      --primary-magenta: #E6007E;
      --accent-cyan: #00F0FF;
      --text-primary: #F0F0FF;
      --text-secondary: #B0B0C0;
      --text-muted: #808090;
      --border-glow: rgba(0, 240, 255, 0.25);
      --shadow-cyan: 0 0 18px rgba(0, 240, 255, 0.3);
      --shadow-magenta: 0 0 22px rgba(230, 0, 126, 0.5);
      --radius-md: 10px;
      --radius-sm: 6px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      --font-display: 'Rajdhani', 'Inter', sans-serif;
      --transition: 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      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 24px;
    }

    /* 背景粒子效果 (装饰) */
    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 30% 40%, rgba(230,0,126,0.12) 0%, transparent 45%),
                  radial-gradient(circle at 80% 20%, rgba(0,240,255,0.08) 0%, transparent 50%);
      pointer-events: none;
      z-index: 0;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(10, 2, 28, 0.78);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.18);
      transition: background var(--transition);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
      color: white;
      font-weight: 700;
      font-size: 1.7rem;
      letter-spacing: 1px;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--accent-cyan);
      filter: drop-shadow(0 0 8px #00F0FF);
    }
    .logo-text {
      background: linear-gradient(135deg, #fff, #E0E0FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: #ddd;
      text-decoration: none;
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      transition: color var(--transition);
    }
    .nav-links a::after {
      content: "";
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-magenta);
      box-shadow: 0 0 10px var(--primary-magenta);
      transition: width 0.25s ease;
    }
    .nav-links a:hover {
      color: white;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .nav-cta {
      background: var(--primary-magenta);
      color: white;
      padding: 10px 24px;
      border-radius: 30px;
      font-weight: 600;
      text-decoration: none;
      box-shadow: 0 0 18px rgba(230,0,126,0.7);
      transition: all 0.25s;
    }
    .nav-cta:hover {
      background: #ff0f92;
      box-shadow: 0 0 28px rgba(230,0,126,0.9);
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: var(--accent-cyan);
      font-size: 28px;
      cursor: pointer;
    }

    /* 板块通用 */
    section {
      position: relative;
      z-index: 2;
      padding: 90px 0;
    }

    h2 {
      font-size: 2.6rem;
      font-weight: 700;
      margin-bottom: 16px;
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 14px;
    }
    h2 .accent-line {
      display: inline-block;
      width: 50px;
      height: 4px;
      background: var(--accent-cyan);
      box-shadow: 0 0 15px var(--accent-cyan);
    }

    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding-top: 100px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      background-color: rgba(11, 0, 26, 0.7);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }
    .hero h1 {
      font-size: 3.8rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
      text-shadow: 0 0 30px rgba(230,0,126,0.4);
    }
    .hero-highlight {
      color: var(--accent-cyan);
      text-shadow: 0 0 18px #00F0FF;
    }
    .hero p {
      font-size: 1.2rem;
      color: #ccc;
      margin-bottom: 32px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary-magenta);
      border: none;
      color: white;
      padding: 14px 36px;
      font-weight: 600;
      border-radius: 40px;
      font-size: 1rem;
      cursor: pointer;
      box-shadow: 0 0 22px rgba(230,0,126,0.6);
      transition: 0.2s;
      text-decoration: none;
    }
    .btn-primary:hover {
      background: #ff1a8c;
      box-shadow: 0 0 32px #E6007E;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 14px 36px;
      border-radius: 40px;
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 18px rgba(0,240,255,0.5);
    }
    .hero-visual {
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .data-sphere {
      width: 280px;
      height: 280px;
      border-radius: 50%;
      background: radial-gradient(circle at 30% 30%, rgba(0,240,255,0.35), rgba(11,0,26,0.9));
      border: 2px solid rgba(0,240,255,0.55);
      box-shadow: 0 0 70px rgba(0,240,255,0.5);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.8rem;
      color: var(--accent-cyan);
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 40px;
    }
    .card {
      background: rgba(18, 6, 38, 0.7);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(0, 240, 255, 0.3);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      transition: all 0.25s;
      box-shadow: 0 8px 22px rgba(0,0,0,0.5);
    }
    .card:hover {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 28px rgba(0,240,255,0.35);
      transform: translateY(-4px);
    }
    .card-icon {
      font-size: 2.4rem;
      color: var(--accent-cyan);
      margin-bottom: 18px;
    }
    .card h3 {
      font-size: 1.6rem;
      margin-bottom: 12px;
    }

    .stat-block {
      display: flex;
      gap: 40px;
      flex-wrap: wrap;
      justify-content: center;
      margin: 50px 0;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-display);
      font-size: 3.4rem;
      font-weight: 700;
      color: var(--primary-magenta);
      text-shadow: 0 0 20px #E6007E;
    }

    .faq-item {
      background: rgba(20, 8, 40, 0.7);
      border: 1px solid rgba(0,240,255,0.25);
      border-radius: var(--radius-sm);
      margin-bottom: 14px;
      padding: 0 22px;
      transition: 0.2s;
    }
    .faq-question {
      font-weight: 600;
      padding: 18px 0;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: #ccc;
      padding-bottom: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 160px;
      padding-bottom: 18px;
    }
    .faq-item.active {
      border-left: 4px solid var(--primary-magenta);
    }

    .footer {
      background: #070012;
      border-top: 1px solid rgba(0,240,255,0.2);
      padding: 60px 0 25px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero p { max-width: 100%; }
      .grid-3 { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-toggle { display: block; }
      .grid-3 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      h2 { font-size: 2rem; }
    }
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: #0B001A;
      position: absolute;
      top: 72px;
      left: 0;
      width: 100%;
      padding: 25px;
      border-bottom: 1px solid #00F0FF;
    }
    .mobile-menu a {
      color: white;
      padding: 12px;
      text-decoration: none;
    }