I noticed a new book had a larger than usual base font size and thought that the original book was made like that. But when I compared (with Calibre viewer) the original azw3 the font size is smaller than for the converted epub.
After comparing and testing css's etc. it seems that the original has a base font size set to 0.83rem. This becomes 1.2rem in the converted epub resulting in the larger font size.
Why is this? I have searched the forum and read the calibre manual without finding any clue. The "Disable font size rescaling" is on. I buy most of my books from Amazon and convert books regularly which almost always work fine.
After checking some other books that had the same font size for azw3 and epub, I noticed that all those books have the base font set in em. The problematic book is set in rem. If I just change "rem" to "em", the converted epub uses the exact same value. (There is no font size set in html.)
azw3 font-size: 0.83rem; becomes epub font-size: 1.2rem;
azw3 font-size: 0.83em; becomes epub font-size: 0.83em;
The css class is used in <body class="xxx".
Not a big problem and easily changed, but I'm curious why this happens and what is the best way to get the same font size in the converted epub.
After comparing and testing css's etc. it seems that the original has a base font size set to 0.83rem. This becomes 1.2rem in the converted epub resulting in the larger font size.
Why is this? I have searched the forum and read the calibre manual without finding any clue. The "Disable font size rescaling" is on. I buy most of my books from Amazon and convert books regularly which almost always work fine.
After checking some other books that had the same font size for azw3 and epub, I noticed that all those books have the base font set in em. The problematic book is set in rem. If I just change "rem" to "em", the converted epub uses the exact same value. (There is no font size set in html.)
azw3 font-size: 0.83rem; becomes epub font-size: 1.2rem;
azw3 font-size: 0.83em; becomes epub font-size: 0.83em;
The css class is used in <body class="xxx".
Not a big problem and easily changed, but I'm curious why this happens and what is the best way to get the same font size in the converted epub.