Enhance dark mode support (#1682)

## Description:

Improved dark mode styling for #1681 

Old:

<img width="536" height="565" alt="image"
src="https://github.com/user-attachments/assets/8b7b5cc5-aa74-4e9b-a814-635c4373d5ab"
/>

New Look:
<img width="766" height="925" alt="image"
src="https://github.com/user-attachments/assets/acd00f2b-7248-4b63-b5c4-a345195d4414"
/>

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I have read and accepted the CLA agreement (only required once).

## Please put your Discord username so you can be contacted if a bug or
regression is found:

DISCORD_USERNAME
totalfailure

src/client/components/NewsButton.ts

@@ -48,7 +48,7 @@ export class NewsButton extends LitElement {
           @click=${this.handleClick}
         >
           <img
-            class="size-[48px]"
+            class="size-[48px] dark:invert"
             src="${megaphone}"
             alt=${translateText("news.title")}
           />