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HTML

              
                <p>Web Components</p>
<h1>Hello World!</h1>
<my-module/>
              
            
!

CSS

              
                h1 {
  color: blue !important;
}
              
            
!

JS

              
                // Create Template
const template = document.createElement('template');
template.innerHTML = `
<h1>Hello World!</h1>
<style>
/* 
* :host targets the shadowDOM, setting all to initial will revert any styles that might be 
* inherited and completely encapsulate your css.
*/
:host {
  all: initial;
}
h1 {
color: red;
}
</style>
`;
// Initialize web component
class MyComponent extends HTMLElement {
    constructor(){
        super();
        this.attachShadow({mode: 'open'});
        this.shadowRoot.appendChild(template.content.cloneNode(true));
    }
    // Define auto-load functions
    connectedCallback(){
        
    }
}
// Register template to HTML dom (HTML Tag, Class)
window.customElements.define('my-module', MyComponent);
              
            
!
999px

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