class CustomHeader extends HTMLElement {
  connectedCallback() {
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        header {
          background-color: rgba(17, 24, 39, 0.8);
          backdrop-filter: blur(10px);
          border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }
        .container {
          max-width: 1200px;
        }
        .logo {
          color: #818cf8;
          font-weight: 700;
          font-size: 1.5rem;
        }
        .nav-link {
          transition: color 0.2s;
        }
        .nav-link:hover {
          color: #818cf8;
        }
      </style>
      <header class="py-4 px-6">
        <div class="container mx-auto flex justify-between items-center">
          <a href="/" class="logo flex items-center">
            <i data-feather="code" class="mr-2"></i>
            CodeFlow
          </a>
          <nav class="hidden md:flex space-x-6">
            <a href="/" class="nav-link">Home</a>
            <a href="/leaderboard.html" class="nav-link">Leaderboard</a>
            <a href="/login.html" class="nav-link">Login</a>
          </nav>
<button class="md:hidden">
            <i data-feather="menu"></i>
          </button>
        </div>
      </header>
    `;
  }
}

customElements.define('custom-header', CustomHeader);