/* roulang page: index */
:root {
      --primary: #00E5FF;
      --primary-dark: #00B8D4;
      --accent: #7C4DFF;
      --bg-deep: #0A0E27;
      --bg-darker: #060B1F;
      --surface-glass: rgba(255, 255, 255, 0.04);
      --surface-glass-hover: rgba(255, 255, 255, 0.08);
      --text-primary: #E0E6FF;
      --text-secondary: #8892B0;
      --border-light: rgba(255, 255, 255, 0.08);
      --border-glow: rgba(0, 229, 255, 0.25);
      --glow-spread: 0 0 20px rgba(0, 229, 255, 0.45);
      --glow-intense: 0 0 32px rgba(0, 229, 255, 0.7);
      --radius-card: 16px;
      --radius-btn: 8px;
      --transition-bounce: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }

    /* 玻璃拟态卡片基础 */
    .glass-card {
      background: var(--surface-glass);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
      transition: var(--transition-bounce);
    }

    .glass-card:hover {
      background: var(--surface-glass-hover);
      border-color: var(--border-glow);
      box-shadow: 0 0 24px rgba(0, 229, 255, 0.15), 0 8px 32px rgba(0, 0, 0, 0.25);
      transform: translateY(-4px);
    }

    /* 导航 */
    .navbar {
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
      padding: 1rem 0;
    }

    .navbar.scrolled {
      background: rgba(10, 14, 39, 0.75);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    .navbar-brand {
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: 0.5px;
      color: var(--primary) !important;
      text-shadow: 0 0 12px rgba(0, 229, 255, 0.6);
    }

    .nav-link {
      color: var(--text-secondary) !important;
      font-weight: 500;
      margin: 0 0.5rem;
      transition: color 0.2s;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--primary) !important;
      text-shadow: 0 0 8px rgba(0, 229, 255, 0.5);
    }

    .navbar-toggler {
      border: 1px solid rgba(255, 255, 255, 0.2);
      color: var(--text-primary);
    }

    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(224, 230, 255, 0.9)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }

    /* 按钮 */
    .btn-primary-glow {
      background: var(--primary);
      color: var(--bg-deep);
      font-weight: 600;
      letter-spacing: 0.05em;
      border: none;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      box-shadow: var(--glow-spread);
      transition: all 0.25s ease;
    }

    .btn-primary-glow:hover {
      background: #33EAFF;
      box-shadow: var(--glow-intense);
      color: #000;
    }

    .btn-ghost {
      background: transparent;
      border: 1px solid rgba(0, 229, 255, 0.5);
      color: var(--primary);
      font-weight: 600;
      letter-spacing: 0.05em;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      transition: all 0.25s ease;
    }

    .btn-ghost:hover {
      background: rgba(0, 229, 255, 0.1);
      border-color: var(--primary);
      box-shadow: 0 0 18px rgba(0, 229, 255, 0.4);
      color: #fff;
    }

    /* 标题 */
    h1 {
      font-size: 3.5rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--text-primary);
    }

    h2 {
      font-size: 2.5rem;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 1.5rem;
      position: relative;
    }

    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 3px;
      background: var(--primary);
      margin-top: 0.5rem;
      box-shadow: 0 0 12px var(--primary);
    }

    .text-secondary-custom {
      color: var(--text-secondary);
    }

    .highlight {
      color: var(--primary);
    }

    /* Hero */
    #hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, #1A1F3A 0%, #0A0E27 70%);
      position: relative;
    }

    .hero-bg-img {
      position: absolute;
      right: 0;
      top: 50%;
      transform: translateY(-50%);
      width: 48%;
      opacity: 0.7;
      pointer-events: none;
    }

    /* 数字动画 */
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
      text-shadow: 0 0 20px rgba(0, 229, 255, 0.6);
    }

    /* 手风琴 */
    .accordion-item {
      background: transparent;
      border: 1px solid rgba(255, 255, 255, 0.06);
      margin-bottom: 12px;
      border-radius: 12px !important;
      overflow: hidden;
    }

    .accordion-button {
      background: rgba(255, 255, 255, 0.03);
      color: var(--text-primary);
      font-weight: 500;
      padding: 18px 24px;
      box-shadow: none;
      border-radius: 12px;
    }

    .accordion-button::after {
      filter: brightness(0) invert(1);
    }

    .accordion-button:not(.collapsed) {
      background: rgba(0, 229, 255, 0.08);
      border-color: rgba(0, 229, 255, 0.2);
      color: var(--primary);
      box-shadow: none;
    }

    .accordion-body {
      color: var(--text-secondary);
      padding: 16px 24px 24px;
    }

    /* 表单 */
    .form-control-glass {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: var(--radius-btn);
      color: var(--text-primary);
      padding: 12px 16px;
    }

    .form-control-glass:focus {
      background: rgba(0, 229, 255, 0.05);
      border-color: var(--primary);
      box-shadow: 0 0 12px rgba(0, 229, 255, 0.4);
      color: #fff;
    }

    /* 页脚 */
    footer {
      background: var(--bg-darker);
      border-top: 1px solid rgba(255, 255, 255, 0.06);
    }

    .social-icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: rgba(255,255,255,0.05);
      color: var(--text-secondary);
      transition: 0.2s;
    }

    .social-icon:hover {
      background: rgba(0,229,255,0.2);
      color: var(--primary);
      box-shadow: 0 0 14px rgba(0,229,255,0.5);
    }

    @media (max-width: 992px) {
      h1 { font-size: 2.8rem; }
      h2 { font-size: 2rem; }
      .hero-bg-img { width: 70%; right: -10%; opacity: 0.5; }
    }

    @media (max-width: 768px) {
      h1 { font-size: 2.2rem; }
      h2 { font-size: 1.8rem; }
      .stat-number { font-size: 2.3rem; }
      section { padding: 60px 0; }
    }