Codeblocks in schelp documents has too much padding after the last line

Dear developers,

When printing, codeblocks in rendered HTML files from schelp docs have excessive vertical padding below the last line. (Please see the screenshot at the bottom of this post.)

I added the following line in the ‘custom.css’ file, but I could not make narrower the padding width.

@media print {
	.CodeMirror-lines {
	padding-bottom: -1em; 
}

However, adding the following lines makes the vertical padding below the last line wider:

@media print {
	.CodeMirror-lines {
	padding-bottom: 1em; 
}

The bottom padding amount in the screen is OK, but why the extra amount of bottom padding is added when printing? How could I remove it?