bug: `BlogAppbar` obstructs text selection below it.

[m4dd0c]

Describe the bug The BlogAppbar was interfering with text selection below it due to improper padding. Adjusting padding ensures better accessibility.

To Reproduce Steps to reproduce the behavior:

1. Visit https://projects.100xdevs.com/tracks/mongodb/MongoDB--Zod--Error-handling-and-Input-validation-7
2. Try scrolling down and select the text below the header within range of pb-6

Expected behavior Users should be able to select text below the header without obstruction while maintaining the existing UI appearance.

Screenshots or GIFs