Browser search finds sidebar text when it is hidden

[ehuss]

Problem

When the sidebar is collapsed (hidden), using the browser's native search will find the hidden words in the sidebar. This is a little confusing because you cannot see the words. This also doesn't seem to be a problem on other sides with a sidebar that collapses. I'm not sure why this is happening.

Steps

1. Go to https://rust-lang.github.io/mdBook/
2. Collapse the sidebar
3. Use your browser's "Find" command and search for "installation" and notice that it seems to find this word even though it isn't visible on the page.

This seems to happen with Firefox, Chrome, and Safari.

Possible Solution(s)

No response

Notes

No response

Version

mdbook v0.4.51

[GuillaumeGomez]

It's because the sidebar is not hidden, just moved out of the viewport. I'll send a fix for it.