Jupyter notebook does not display correctly on github

Here is my notebook: https://gist.github.com/tung2389/772de25aede8bcf0c2a1e6251fa45063

When I open my notebook in Jupyter, it looks fine:

But when I upload my notebook to GitHub or viewing it is using https://nbviewer.jupyter.org/, it looks weird:

In my notebook, I only use matplotlib version 3.3.0, numpy 1.19.1 and pandas 1.0.5

What am I doing wrong?

Thank you so much!