css problem

hi all

i did open writen in the personal site
i did a document
i insert text
i go to html view
i insert CSS in CSS tab

body {
padding-top:20mm;
padding-bottom:20mm;
padding-left:40mm;
padding-right:20mm;
}

i save go to document view
in site setings the borders are zero
now i go to print preview
i click print as PDF
the boorders look good

but the bottom page borser looks not good on each page!
it writes until last line at very buttom of page

and at site 2 it beginns at very top of site with first line

i also tryed with CSS margins but thats totaly woerse
it shows and prints the document totaly wrong

and with CSS pading it looks near to as planed
how i can fix this page buttom top issue?

the problem is also that in your page settings you serve the percent% option
but i wanna work with mm or cm

you should integrate in your page option millimeters and centimeters and pixel and so on
and not only %

and just in the moment how can i fix this ?

thanks