>>106366990
That's just how the sidebar of the pdf reader is styled, some people like the gaps I guess. To change it you need to make a userContent.css file (different from userChrome.css but in the same directory) with this css:
@-moz-document regexp(".+\.pdf") {
.thumbnail {
margin: 2px 2px !important; /*reduce gaps between pages*/
border-width: 5px !important; /*make the highlighted area around each page smaller*/
}
#thumbnailView {
padding: 0 !important; /*remove the panel's padding around all of the pages so that it actually starts at the top left*/
width: 100% !important; /*remove the -60px from this so that it refelcts the removed padding*/
}
}