Introduction of Editor maximum width setting (which is great) added a problem with center justified notes (which is not great, imho). With a help from some guys from the forum I was able to fix it with a custom css:
=== userstyle.css
.mce-content-body {
margin-left: 6px;
}
=== userchrome.css
div.CodeMirror-sizer {
margin-left: 6px !important;
}
#rendered-md {
margin-left: 6px !important;
}
Both files have to reside in ~/.config/joplin-desktop/
(OS X or Linux) or %userprofile%\.config\joplin-desktop\
(Windows).
Make sure you restart the app after editing the files.