In this lab, you'll work with Custom Elements API to create a custom HTML element named my$-$card. This element will extend a 'div' HTMLElement. You will use a constructor to create a shadow root for your custom element, set the color of the my$-$card element to blue, and finally add an h$1$ element with the text 'Hello, World!$\text{'}.$

Concepts

This lab primarily explores Custom Elements API, part of Web Components technologies. The key concepts required for this lab include:

Custom Elements: This allows developers to define their own custom HTML tags.

Shadow DOM: This provides encapsulation by allowing