class CustomHeader extends HTMLElement {
  connectedCallback() {
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        :host {
          display: block;
        }
        
        header {
          background: rgba(31, 41, 55, 0.8);
          backdrop-filter: blur(10px);
          border-bottom: 1px solid rgba(255, 255, 255, 0.1);
          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-weight: 700;
          font-size: 1.5rem;
          background: linear-gradient(90deg, #3b82f6, #8b5cf6);
          -webkit-background-clip: text;
          -webkit-text-fill-color: transparent;
        }
        
        nav ul {
          display: flex;
          list-style: none;
          gap: 2rem;
        }
        
        nav a {
          color: #d1d5db;
          text-decoration: none;
          font-weight: 500;
          transition: color 0.3s ease;
          display: flex;
          align-items: center;
          gap: 0.5rem;
        }
        
        nav a:hover {
          color: #3b82f6;
        }
        
        @media (max-width: 768px) {
          .container {
            flex-direction: column;
            gap: 1rem;
          }
          
          nav ul {
            gap: 1rem;
          }
        }
      </style>
      
      <header>
        <div class="container">
          <div class="logo">
            <svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
              <path d="M11.767 19.089c4.924.868 6.14-6.025 1.216-6.894m-1.216 6.894L5.86 18.047m5.908 1.042-.347 1.97m1.563-8.864c4.924.869 6.14-6.025 1.215-6.893m-1.215 6.893-3.94-.695m5.155-6.2-.347-1.97m-5.807 4.048c4.924.868 6.14-6.026 1.215-6.894m-1.215 6.894L5.86 5.953m5.908-1.042-.347-1.97M7.48 9.855c-4.924-.868-6.14 6.026-1.215 6.894m1.215-6.894l5.908 1.042m-5.908-1.042-.347 1.97"/>
            </svg>
            Bitcoin Transfer Pro
          </div>
          
          <nav>
            <ul>
              <li><a href="#"><i data-feather="home"></i> Dashboard</a></li>
              <li><a href="#"><i data-feather="activity"></i> Transactions</a></li>
              <li><a href="#"><i data-feather="settings"></i> Settings</a></li>
            </ul>
          </nav>
        </div>
      </header>
    `;
    
    // Initialize Feather icons
    const featherScript = document.createElement('script');
    featherScript.src = 'https://cdn.jsdelivr.net/npm/feather-icons/dist/feather.min.js';
    featherScript.onload = () => {
      feather.replace();
    };
    this.shadowRoot.appendChild(featherScript);
  }
}

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