Tablet view (~768px) still uses single-column layout on list pages

**Describe the bug**
At tablet screen widths (around 768px), list-based pages such as Projects, Chapters, and Committees continue to render in a single-column layout instead of adapting to a multi-column grid. This results in inefficient use of available screen space and excessive vertical scrolling on tablet devices.

**To Reproduce**
Steps to reproduce the behavior:

1. Open the site in a browser
2. Open developer tools and set the viewport width to ~768px (tablet size)
3. Navigate to any list page (Projects / Chapters / Committees)
4. Observe that the content is displayed in a single column

**Expected behavior**
At tablet breakpoints, list pages should switch to a 2-column grid layout to better utilize horizontal space and improve readability.

**Are you going to work on fixing this?**

- [x] Yes
- [ ] No

**Screenshots**

**Desktop (please complete the following information):**

- OS: Windows 11
- Browser: Chrome
- Version: Latest

**Smartphone (please complete the following information):**

- Device: N/A
- OS: N/A
- Browser: N/A
- Version: N/A

**Additional context**
This behavior appears consistent across multiple list-based pages, suggesting it may be related to shared layout or breakpoint configuration.