class CardLoader extends HTMLElement {
  connectedCallback() {
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        .loader {
          display: flex;
          flex-direction: column;
          gap: 1rem;
        }
        .skeleton {
          background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
          background-size: 200% 100%;
          animation: shimmer 1.5s infinite;
          border-radius: 0.5rem;
        }
        @keyframes shimmer {
          0% { background-position: 200% 0; }
          100% { background-position: -200% 0; }
        }
      </style>
      <div class="loader">
        ${Array(3).fill().map(() => `
          <div class="skeleton" style="height: 120px;"></div>
        `).join('')}
      </div>
    `;
  }
}

customElements.define('card-loader', CardLoader);