[dracodoc]

I was trying to use ebook-convert.exe to convert txt to epub, but the --base-font-size was not working for me.
My command is like this:

ebook-convert f:\x.txt f:\x.epub --input-encoding=GBK --no-default-epub-cover --single-line-paras --base-font-size=18 --remove-paragraph-spacing --output-profile=sony --extra-css=f:\style.css

but the message said

Flattening CSS and remapping font sizes...
Source base font size is 12.00000pt
Cleaning up manifest...

maybe it's because the extra css overrode the base font size? If so, how should I modify my css? My current extra css is like this

@font-face {
font-family: "Swis721 BT";
font-weight: normal;
font-style: normal;
src: url(res:///Data/FONT/tt0003m_.ttf)
}
@font-face {
font-family: "Swis721 BT";
font-weight: bold;
font-style: normal;
src: url(res:///Data/FONT/tt0003m_.ttf)
}
@font-face {
font-family: "Swis721 BT";
font-weight: normal;
font-style: italic;
src: url(res:///Data/FONT/tt0003m_.ttf)
}
@font-face {
font-family: "Swis721 BT";
font-weight: bold;
font-style: italic;
src: url(res:///Data/FONT/tt0003m_.ttf)
}
body {
font-family: "Swis721 BT"
}
p.p_normal {
font-family: "Swis721 BT"
}
p{
font-family: "Swis721 BT"
}
h3.chapter_heading{
font-family: "Swis721 BT"
}