Whenever I open an .epub file in Calibre e-book viewer, the text is full-justified. I want to set left-justification as a permanent preference for all .epub files. How can I do that?

I'm running the latest version of Windows 10 Home Edition 64-bit, and the latest version of Calibre (I think), 5.14.

Thanks for any help.

UPDATE: I submitted my question to the MobileRead forum's thread, Custom CSS Stylesheets for Calibre's Viewer, and received an answer from Kovid Goyal, himself (the creator of Calibre). The solution is to use a style sheet (as suggested by Christian__N, below) with this entry:

* { text-align: left !important; }

https://www.mobileread.com/forums/showthread.php?t=51500

In the Ebook Viewer application, click on the Hammer [gear] icon (Preferences), then put the code in the "User stylesheet" edit box and click OK. Have an ebook open in the viewer for the full effect, before and after.