Drupal 8.x

In my Bartik theme, there is a pencil icon, which leads to the contextual edit menu ("Configure block" / "Remove block" / "Edit menu" / ...). There are, however, a couple of problems with this icon. First, but let's skip this one, it's very ugly. 

Hello all,

I noticed that my font size is very small by default. It is not nice to read. How can I make the font size bigger so that you don't need a magnifying glass to read the texts?

Thank you for help!

I moved my site from one server to another after which images have stopped showing up, Could anyone please guide me on how to solve this issue?

The URL is as follows:

https://www.japaneseautoworld.com/

Thanks and regards

I'm looking for a way for merging Forum threads and moving comments posted to the wrong thread into the right one.

I did a bunch of searching and finally found the "Comment Mover" module which appears to do what I need. However, it's only available for D7. https://www.drupal.org/project/comment_mover

Is there any Drupal 8 (or 9) equivalent to the D7 "Comment Mover" module? Or another solution for the problem of merging Forum threads etc?

Thank you.

I tred to move Drupal 8 files from the subfolder to the root. But it gave the following error messages.  Then, I reversed the process.  Could anyone suggest what could be the best way to start showing a site that is actually in a subfolder instead of in the root directory?  Manua;lly moving files and folders gives the following error messages.