I have not yet published a book, but from reading many books over the years I have noticed that some authors will change the font, make things bold, or change the size of the words for increased emphasis or some other reason. I have also noticed that when reading electronic copies of the same works, that those artistic details are lost. .Is there a way to self publish and still be able to be artistic with the font and sizing of the words with the finished book?
The simple answer is no. Electronic reading devices contain a limited number of resident fonts and have facilities for resizing which forces re-pagination. You will notice on Kindle that page numbers are estimated. Your work will be displayed on anything from a 40" LCD screen to a 4" Smartphone.
Formatting may be maintained and controlled by saving your work as a PDF with embedded fonts. However, this results in awkward output. If your book is represented by 1 page per screen on a small device the text may be so small as to render it unreadable. If you magnify the text is will not re-paginate. Subsequently you would need to scroll left and right to read each individual line.