Lectures: Misaligned "Download Complete PDF" Button

[laxerhd]

Describe the bug

The Download Complete PDF button on the Lectures page is not aligned
properly with the Lecture Units text to its left (see attached picture).

I would like to create an PR for that.

To Reproduce

1. Create a Course
2. Click on Manage
3. Click on Lectures
4. Create new Lecture
5. Click on Units
6. Click on Files
7. Upload a pdf
8. Go to the “Lectures” tab and see how it is misaligned

Expected behavior

The blue download button should be aligned with the text on its left side.

Screenshots

Which version of Artemis are you seeing the problem on?

7.7.0

What browsers are you seeing the problem on?

Chrome, Safari, Microsoft Edge, Firefox, Other (specify in "Additional context")

Additional context

Vivaldi, etc. (also on mobile devices)

Relevant log output

No response