fix(ui): Adjust sidebar brightness for improved readability

[anjaliushadubey]

Which issue does this PR close?

• Closes UI Bug: Sidebar remains in light theme when "Enable Dark Mode" is activated #120

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Rationale for this change

Users reported or experienced difficulty reading the sidebar content due to low contrast between the text and the sidebar background, particularly on certain displays or lighting conditions.

This change ensures all sidebar elements (links, text, icons) are easily readable and meet current accessibility standards for contrast, improving overall user experience.

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What changes are included in this PR?

• Modified the CSS for the main sidebar container (e.g., .sidebar-container).
• Specifically adjusted the background color (lightened the color or increased the opacity).
• Optional: Ensured the sidebar text color has high enough contrast against the new background.

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Are these changes tested?

Yes, these changes have been tested visually across:

• Multiple devices (e.g., laptop, external monitor).
• Different lighting conditions.
• Contrast testing tools were used to verify that the foreground text meets the minimum required contrast ratio against the new background color.

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Are there any user-facing changes?

Yes, this is a user-facing visual improvement. The sidebar will appear brighter with higher contrast, making all text and interactive elements easier to read and access.

Before

After

[github-actions]

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In the meantime, please double-check the file changes and ensure that all commits are accurate.

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