Fixes #2002

Added gradient glow, smooth scale-up animation, and background transition to the Join Discord button for a more visually engaging hover state.

What does this PR do?

This PR improves the interactivity and visual appeal of the "Join Discord" button by:

• Adding a gradient glow around the button
• Implementing a smooth scale-up effect on hover
• Applying a gradient background transition on hover

This change is purely visual and does not alter the existing functionality of the button.

Fixes #(issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Chore (refactoring code, technical debt, workflow improvements)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How should this be tested?

• Test A – Hover over the "Join Discord" button and observe the gradient glow, smooth scale-up, and background color transition.
• Test B – Confirm that the button link still works as intended.

Mandatory Tasks

• Make sure you have self-reviewed the code. A decent size PR without self-review might be rejected.

Checklist

• I have read the contributing guide
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have checked if my PR needs changes to the documentation
• I have checked if my changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have checked if new and existing unit tests pass locally with my changes