Fix Collaborations light theme styling and add Structure-to-Collaborations navigation

✨ Feature Request

What feature would you like to see added to viswam.ai?
Fix the Collaborations page light theme styling and add a Collaborations navigation link at the bottom of the Structure section.

Describe the feature in detail. Be clear about the use case and who it helps.
The Collaborations page currently does not appear correctly in light theme and needs UI fixes so it looks consistent with the rest of the website. In addition, the Structure section should include a Collaborations link at the bottom so users can easily navigate from Structure to the Collaborations page.

This helps users who are browsing in light mode and improves navigation between related pages.

Why is this feature important or useful?
It improves visual consistency in light theme, avoids broken or unclear page presentation, and makes it easier for users to discover the Collaborations page from the Structure section.

Any suggestions for how it could work or look? Add diagrams, examples, or references if possible.

• Update the Collaborations page styles so text, background, and section cards display properly in light theme
• Add a Collaborations item/button/link at the bottom of the Structure page
• Clicking it should redirect users to the Collaborations page

Additional context or notes
This is both a UI fix and a navigation improvement. The goal is to make the Collaborations page usable in light theme and better connected to the Structure page.

ScreenShots