[ENHANCEMENT] Update "Back to Top" button color for better visibility.

[Sreekuttan-007]

Is your feature request related to a problem? Please describe.
The "Back to Top" button is currently styled in black, which causes it to camouflage with the dark portions of the website, making it difficult for users to locate and use.

Describe the solution you'd like
I would like to update the styling/colour of the "Back to Top" button to ensure it maintains proper contrast against both the light and dark themes, improving accessibility and visual consistency.

Describe alternatives you've considered
I considered increasing the drop shadow, but changing the button colour or adding a border/accent colour would be a more effective long-term solution for theme compatibility.

Additional context
I am participating in GSSoC 2026 and would like to contribute!

[kanishka-2007-tech]

hi @Aditya948351 @devpathindcommunity-india i would like to work on this issue under gssoc 26 . I will raise a PR in 1-2 days once the issue is assigned to me

[saurabhhhcodes]

Opened a fix PR for this: #325

What changed:

• replace the hard black back-to-top button styling with a higher-contrast cyan treatment
• add hover and focus states that stay visible in both light and dark themes
• add a tiny regression test to pin the theme-safe classes

Local validation:

• python3 -m pytest tests/test_back_to_top_styles.py -q
• git diff --check

[Divyansh-2024]

Hi @Aditya948351 @devpathindcommunity-india i would like to work on this issue. Please assign this task to me