I cloned some repos (calendar-card, weather-card) and opened them up in VS Code to see how they work to see if I could write my own…
But first myClass extends HTMLElement gives me a ReferenceError: HTMLElement is not defined
commenting that out:
customElements.define('group-card', GroupCard); gives ReferenceError: customElements is not defined
Are there libraries I’m missing? Where can I find them?
Basically, what do I need to build a custom card in VS Code?