class CustomHeader extends HTMLElement {
  connectedCallback() {
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        :host {
          display: block;
        }
        
        header {
          background: rgba(15, 23, 42, 0.8);
          backdrop-filter: blur(10px);
          border-bottom: 1px solid rgba(139, 92, 246, 0.2);
          padding: 1rem 0;
          position: sticky;
          top: 0;
          z-index: 100;
        }
        
        .container {
          max-width: 1200px;
          margin: 0 auto;
          padding: 0 1rem;
          display: flex;
          justify-content: space-between;
          align-items: center;
        }
        
        .logo {
          display: flex;
          align-items: center;
          gap: 0.75rem;
          font-family: 'Orbitron', sans-serif;
          font-weight: 700;
          font-size: 1.5rem;
          background: linear-gradient(90deg, #8b5cf6, #ec4899, #f43f5e);
          -webkit-background-clip: text;
          -webkit-text-fill-color: transparent;
          background-clip: text;
        }
        
        nav ul {
          display: flex;
          list-style: none;
          gap: 2rem;
        }
        
        nav a {
          color: #cbd5e1;
          text-decoration: none;
          font-weight: 500;
          transition: color 0.3s;
          display: flex;
          align-items: center;
          gap: 0.5rem;
        }
        
        nav a:hover {
          color: #8b5cf6;
        }
        
        .mobile-menu-btn {
          display: none;
          background: none;
          border: none;
          color: white;
          cursor: pointer;
        }
        
        @media (max-width: 768px) {
          nav ul {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            right: 0;
            background: rgba(15, 23, 42, 0.95);
            flex-direction: column;
            padding: 1rem;
            gap: 1rem;
          }
          
          nav ul.active {
            display: flex;
          }
          
          .mobile-menu-btn {
            display: block;
          }
        }
      </style>
      
      <header>
        <div class="container">
          <div class="logo">
            <i data-feather="globe" style="color: #8b5cf6;"></i>
            <span>Cosmic Explorer</span>
          </div>
          
          <button class="mobile-menu-btn" id="menuToggle">
            <i data-feather="menu"></i>
          </button>
          
          <nav>
            <ul id="navMenu">
              <li><a href="#"><i data-feather="home"></i> Home</a></li>
              <li><a href="#"><i data-feather="image"></i> Gallery</a></li>
              <li><a href="#"><i data-feather="info"></i> About</a></li>
              <li><a href="#"><i data-feather="book"></i> Resources</a></li>
            </ul>
          </nav>
        </div>
      </header>
    `;
    
    // Add menu toggle functionality
    setTimeout(() => {
      const menuToggle = this.shadowRoot.getElementById('menuToggle');
      const navMenu = this.shadowRoot.getElementById('navMenu');
      
      menuToggle.addEventListener('click', () => {
        navMenu.classList.toggle('active');
        const menuIcon = menuToggle.querySelector('[data-feather]');
        if (navMenu.classList.contains('active')) {
          menuIcon.setAttribute('data-feather', 'x');
        } else {
          menuIcon.setAttribute('data-feather', 'menu');
        }
        feather.replace();
      });
      
      feather.replace();
    }, 0);
  }
}

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