text: class ShadowDom extends HTMLElement {
      constructor() {
        super();
    
        const shadow = this.attachShadow({ mode: 'open' });
        
        const wrapper = document.createElement('div');
        wrapper.setAttribute('class', 'wrapper');
    
        const style = document.createElement('style');
        style.textContent = `
          .wrapper {
            width: 100px;
            height: 100px;
            background-color: blue;
          }
        `
        
        shadow.appendChild(style);
        shadow.appendChild(wrapper);
      }
    }
    
    customElements.define('shadow-dom', ShadowDom)