Fix Contribution Button by Adjusting z-index in CSS for Main Tag (Issue #1997)

[onkarbhojane]

This pull request addresses issue #1997, where the Contribution Button on the main page was not functional. The root cause was identified as a CSS z-index conflict.

Changes Made Updated the CSS file to modify the z-index value of the

tag to ensure that it does not overlap and block the Contribution Button.

Testing Verified that the Contribution Button is now clickable and functional on the main page. Ensured that other elements on the page maintain their intended stacking order and functionality. Issue Link

Closes #1997

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