There are a lot of examples you can find in this thread:
https://www.mobileread.com/forums/sh...ad.php?t=51500
This is an example I use for calibre viewer (is not implemented for the server application):
https://www.mobileread.com/forums/sh...&postcount=202
(Download the attached file and save it where you want (I use the calibre user configuration directory)
My settings in the viewer:
User style sheet (pic 6):
Code:
body { background:url("file:///c:/Users/YOUR_USERNAME/AppData/Roaming/calibre/resources/viewer/book_white.m2.bmp") no-repeat center center fixed !important;
-webkit-background-size: cover !important;
-moz-background-size: cover !important;
-o-background-size: cover !important;
background-size: cover !important;
}