Day 5 & Day 11 sections stack too soon

[22antonio]

Describe the bug
Currently the Introduction to Bootstrap Utilities and Typography on Day 5 stacks sooner than the rest of the page.

This also happens on Day 11 CSS Preprocessors section.

To Reproduce
Steps to reproduce the behavior:

1. Navigate to Day 5 or Day 11
2. Shrink the screen width
3. Observe the section stacks before the rest of the sections.

Expected behavior
Styling should match the rest of the page.

Screenshots
Day 5:

Day 11:

Other notes
This also happens on Day 12 but I almost feel like it works to have Day 12 behave like this.