Theme support (light/dark via Tailwind class strategy)

[YaronZaki]

• Difficulty: good-first-issue · Effort: M · Priority: P2
• Impact: every render
• Problem Statement
  The Tailwind config (quantara/frontend/tailwind.config.js) defines
  theme variables under colors.primary, colors.backdrop-dark, etc.,
  sourced from CSS variables. There is no dark: strategy class set;
  users on light backgrounds see unreadable contrasts.
• Why It Matters
  A theme switchable by user preference aligns with WCAG 2.2 SC 1.4.6
  (Contrast) and is a frequently requested feature on community boards.
• Expected Outcome
  class="dark" strategy in tailwind.config.js. prefers-color-scheme
  default detection + a user-toggleable button in the global nav. CSS
  vars exposed in :root and re-scoped under :root.dark.
• Acceptance Criteria
  • localStorage.setItem("theme", "dark") flips the body class.
  • Light renders above Axe DevTools AA contrast (4.5:1 for body text).
  • Audit on every Tailwind colour token.
• Implementation Notes

  // tailwind.config.js (darkMode: 'class')
  module.exports = {
    darkMode: 'class',
    theme: { extend: { colors: { /* … */ } } },
  }

• Files / Modules Affected
  • quantara/frontend/tailwind.config.js
  • new: quantara/frontend/src/contexts/ThemeContext.jsx
• Dependencies: standalone; pairs with #82 (A11y).

[OluRemiFour]

Hi Maintainer,
Interested in working on this issue. I'll implement the requested changes and ensure everything is properly tested before submission.

Payout wallet (Stellar): GALHFNUOYOY4S5CNRK7OI7NKS7UNWYGSJII2POQ6XQKWMUVLKZ2SAWMP GrantFox OSS campaign — smart escrow payout on merge.

[eischideraa-unn]

Hello Maintainer,

I'd like to work on this issue. I have experience contributing to similar codebases and can quickly get up to speed with the existing architecture. My plan is to identify the root cause, implement a clean fix that follows project conventions, and thoroughly test the solution before submitting a PR.

Looking forward to contributing.

[grantfox-oss]

🦊 GrantFox — @eischideraa-unn has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #276)
2. Your PR will be reviewed by the Quantarq maintainers

Good luck! Track your progress on GrantFox.