Update index.css

[kes-H-av]

change some colours

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• 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

[github-actions]

This PR has not seen any action for a while! Closing for now, but it can be reopened at a later date.

[github-actions]

This PR has not seen any action for a while! Closing for now, but it can be reopened at a later date.

[Copilot]

Pull Request Overview

This PR updates the CSS styling for the typing game solution by adding global body styles with a dark theme.

• Added dark theme styling with black background and white text for the body element

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

The yellow highlight color on black background may not provide sufficient contrast for accessibility. Consider using a darker yellow or different color that meets WCAG contrast requirements.

Suggested change

	background-color: yellow;
	background-color: #FFD600;
	color: #000;

[leestott]

@kes-H-av pleae see comments and correct

[github-actions]

This PR has not seen any action for a while! Closing for now, but it can be reopened at a later date.