[Bug]: Dark mode flickers to light mode for a split second on every page navigation

[Priyanka0205-CSE]

Bug Description

Hey, found something that's been bugging me for a while now.

I have dark mode enabled and every time I navigate between pages (like going from Leaderboard to Profile or Friends) the page briefly flashes white before settling back to dark mode. It's really noticeable especially at night and honestly quite jarring.

Feels like the theme isn't being applied before the page renders. Maybe the ThemeContext is initializing with a default light value before reading from localStorage?

Steps to reproduce:

1. Enable dark mode
2. Navigate between any two pages using the sidebar
3. Watch for a white flash during the transition

Expected: Theme should stay consistent during navigation with zero flicker
Device: Windows 11, Chrome 124

[Priyanka0205-CSE]

Hi @indresh404

I would like to work on this issue as part of GSSoC'26.

Could you please assign it to me?

[github-actions]

Thank you for opening this issue, @Priyanka0205-CSE! 🚀

A maintainer (@indresh404) will review this and assign it to you if the issue is valid. Please wait for assignment before you start working on it!

Happy contributing! 🌟

[saurabhhhcodes]

I would like to work on this. The fix is to apply the theme from localStorage synchronously before the first render to prevent the white flash.

[Xenon010101]

/assign

[github-actions]

Hey @Xenon010101! This issue has been assigned to you. 🎉

Please go through our Contributing Guide before you start. Make sure to open a PR that references this issue (e.g. Closes #558).

Happy contributing! 🚀