Use static get styles()

[balloob]

With Lit Element 2.0.0-rc2, a new static get styles() was introduced. It will use performance optimizations for stylesheets when possible. This new method should return an array of CSS stylesheets that are rendered using the imported css tag from lit-element.

// Example
import haStyle from "./ha-style.ts";

class Bla extends LitElement {
      static get styles() {
        return [
          css`.header { color: green; }`,
          haStyle,
        ];
      }
}

We should migrate our elements to use this.

[iantrich]

Do you want to keep this open as a reminder for conversion?

[balloob]

Nah