Codeblocks are interfering with the slide content, when they're supposed to be at the end of the slide.

[vcoder1]

Codeblocks not rendered as expected
Codeblocks are not working as expected; they aren't rendered orderly.
Look at the screenshots.
The codeblock which is supposed to be at the bottom of the slide happens to overlap on the slide content.

Steps to reproduce the bug
Here is the slide content in the markdown file :

For example, if the range −999 999
to 999 999 is desired, k6 may be
established as a constant with an
appropriate value by the fortran statement
integer, parameter :: k6 = selected_int_kind(6)
and used in constants thus:

-123456_k6
+1_k6
2_k6

---

Steps used to install present:
sudo pip3 install present
Expected behavior

This codeblock:

-123456_k6
+1_k6
2_k6

should appear at the bottom of the slide, at the end. However, it seems to interfere with the slide content.

Screenshots

Here's what is rendered:

My code looks like this:

Environment

• OS: [e.g. Ubuntu Linux 20.04]
• Terminal emulator: [e.g. gnome-terminal]
• Python version: [e.g. 3.8.2]
• present version: [e.g. 0.6.0]