accessibility: ensure minimum contrast ratio of 4.5:1 for Toast notification message text

[SourabhX16]

Problem Statement

Muted gray text colors on semi-transparent toast backgrounds yield a contrast ratio of 3.2:1.

Why It Matters

Low text contrast impairs toast readability for low-vision users.

Expected Behaviour

Update toast notification text colors to high-contrast tokens (#f8fafc on dark translucent fill).

Acceptance Criteria

• Toast text contrast ratio meets or exceeds WCAG 2.1 AA 4.5:1 requirement.
• Verified across success, error, and info toast types.
• Readability enhanced.

Likely Affected Files / Components

• src/components/Toasts.tsx
• src/styles/globals.css

[mittalsonal]

Hi maintainers, I would like to work on this issue under GSSoC '26.\n\n### Proposed Solution\n- Audit the toast notification styles/components for success, error, and info variants.\n- Replace low-contrast muted message text with high-contrast tokens that meet WCAG 2.1 AA contrast requirements on the current translucent toast backgrounds.\n- Keep the visual hierarchy intact while improving readability across toast types.\n- Verify the affected toast variants after the style update and include testing details in the PR.\n\nPlease assign this to me if it is available.