How can I modify the size of markdown texts?

Notebook
1

Hi,

I need only one level in my document, but the size of the first level title is too big for me, and the third level looks good to me. I need to do

### XYZ... 
### ABC... 

however, when I export it to pdf, I will see

0.0.1 XYZ
0.0.2 ABC

which is too long for me. Is there any way to adjust the size of the first level or remove the “0.0.1” and “0.0.2” from the pdf?

Thanks,

J