Direct annotations through CSS, is it practical?

[ReaderMoa]

I'm quite a fan of annotations but the fact that they don't really stay inside EPUB files sort of bugs me.

So how viable and safe is it to simply edit the CSS of the EPUB itself, through the Calibre EPUB Editor for instance, using a class like

```
.highlightgreen {
background-color: lightgreen;
}
```

Do you think it would be safe and is there a plugin that supports it? The methods most people mention don't involve editing the EPUB directly but using external metadata

[lomkiri]

First of all, I guess you're aware that you can annotate an epub wjhen you're using the calibre's epub reader, annotations are stored inside the epub itself, in the "calibre_bookmarks.txt" file (in the prefs, choose miscellaneous / "Keep a copy of annotations/bookmarks in the e-book file, for easy sharing").

But, of course, they are readable only with the calibre's epub reader itself, not even the editor is understanding the content of the file calibre_bookmarks.txt.

If you want to be able to share the annotations with other people that don't use calibre, you're solution is possible, but it needs to write a plugin that, for example with a button on the toolbar, get the current selection and put it inside a span using the css class you've told (the same plugin would create this class at its first call in the current epub). So it's not a trivial solution.

Edit: Or another one that — using the code that Kovid already wrote in the ebook-viewer — would get the content of calibre_bookmarks.txt and put it inside the code of the epub.

[theducks]

The CSS is where you create a STYLE that the book can use.
You would the need to add a span class= "highlightgreen"> around the annotation anchor text.

[Karellen]

Originally Posted by ReaderMoa

I'm quite a fan of annotations but the fact that they don't really stay inside EPUB files sort of bugs me.

So how viable and safe is it to simply edit the CSS of the EPUB itself, through the Calibre EPUB Editor for instance, using a class like

```
.highlightgreen {
background-color: lightgreen;
}
```

Do you think it would be safe and is there a plugin that supports it? The methods most people mention don't involve editing the EPUB directly but using external metadata

Jumping between a kindle, libra, iBooks and pc when reading really destroyed any hope of reliable highlighting. So I use a similar method using the <mark> tag

<mark>This is some text I need to highlight/annotate</mark>

My CSS
mark {
background-color: yellow;
}

https://developer.mozilla.org/en-US/.../Elements/mark