Text in background textarea seen on selection (Chrome 66)

[vgavro]

Well, when text is selected - it's actually also selected in background textarea. If you're using only text it's not a big problem (but it don't looks clean anyway!), but you have more problems when you're replacing some characters in prism (emoji, for example) - so you get image in foreground and text in background, which both seen on selection and interfere with each other (at least in Chrome, haven't tested in other browser, but I expected it is reproduced there also). Here is screenshot (for text-only case) https://ibb.co/cRFvFo
I understand that CodeFlask is tiny project, but there is no such problem in CodeMirror, which is also using background textarea, so it would be useful if you clarify this thing in documentation if this can't be fixed for some reason, thank you.

[pfgithub]

Also true on firefox and probably every browser. The text in the background is visible, it just has color:white