feat(docs): add guide for shadow dom & constructable stylesheets

docs/src/content/docs/guides/shadow-dom.md

@@ -10,7 +10,19 @@ Try it now [on CodePen ↗](https://codepen.io/ayoayco-the-styleful/pen/VwRYVPv?
 Example:
 
 ```js
+class ShadowElement extends WebComponent {
   static shadowRootInit = {
-    mode: "closed",
-  };
+    mode: 'open', // can be 'open' or 'closed'
+  }
+
+  get template() {
+    return html`
+      <div>
+        <p>Wow!?</p>
+      </div>
+    `
+  }
+}
+
+customElements.define('shadow-element', ShadowElement)
 ```

docs/src/content/docs/guides/styling.md

@@ -3,6 +3,15 @@ title: Styling
 slug: styling
 ---
 
+There are two ways we can safely have scoped styles:
+
+1. Using style objects
+2. Using the Shadow DOM and constructable stylesheets
+
+It is highly recommended to use the second approach, as with it, browsers can assist more for performance.
+
+## Using style objects
+
 When using the built-in `html` function for tagged templates, a style object of type `Partial<CSSStyleDeclaration>` can be passed to any element's `style` attribute. This allows for calculated and conditional styles. Read more on style objects [on MDN](https://developer.mozilla.org/en-US/docs/Web/API/CSSStyleDeclaration).
 
 Try it now with this [example on CodePen ↗](https://codepen.io/ayoayco-the-styleful/pen/bGzXjwQ?editors=1010)
@@ -10,7 +19,7 @@ Try it now with this [example on CodePen ↗](https://codepen.io/ayoayco-the-sty
 ```js
 import { WebComponent } from 'https://unpkg.com/web-component-base@latest/index.js'
 
-class StyledElements extends WebComponent {
+class StyledElement extends WebComponent {
   static props = {
     emphasize: false,
     type: 'warn',
@@ -41,5 +50,39 @@ class StyledElements extends WebComponent {
   }
 }
 
-customElements.define('styled-elements', StyledElements)
+customElements.define('styled-elements', StyledElement)
+```
+
+## Using the Shadow DOM and Constructable Stylesheets
+
+If you [use the Shadow DOM](/shadow-dom), you can add a `static styles` property of type string which will be added in the `shadowRoot`'s [`adoptedStylesheets`](https://developer.mozilla.org/en-US/docs/Web/API/Document/adoptedStyleSheets).
+
+```js
+class StyledElement extends WebComponent {
+  static shadowRootInit = {
+    mode: 'open',
+  }
+
+  static styles = `
+    div {
+      background-color: yellow;
+      border: 1px solid black;
+      padding: 1em;
+
+      p {
+        text-decoration: underline;
+      }
+    }
+  `
+
+  get template() {
+    return html`
+      <div>
+        <p>Wow!?</p>
+      </div>
+    `
+  }
+}
+
+customElements.define('styled-elements', StyledElement)
 ```

examples/constructed-styles/index.js

@@ -2,11 +2,6 @@
 import { WebComponent, html } from '../../src/index.js'
 
 class StyledElements extends WebComponent {
-  static props = {
-    condition: false,
-    type: 'info',
-  }
-
   static shadowRootInit = {
     mode: 'open',
   }