<body>
<script>
// Define Composite Element Class
class CompositeElement extends HTMLElement {
constructor() {
super();
const shadowRoot = this.attachShadow({ mode: 'open' });
shadowRoot.innerHTML = `
<style>
/* Define styles for the composite component */
.container {
border: 1px solid #ccc;
padding: 20px;
}
</style>
<div class="container">
<slot name="header"></slot>
<slot name="content"></slot>
<slot name="footer"></slot>
</div>
`;
}
}
// Define Composite Element
customElements.define('composite-element', CompositeElement);
</script>
<composite-element>
<div slot="header">Header</div>
<div slot="content">Content</div>
<div slot="footer">Footer</div>
</composite-element>
</body>