I want to edit `ItemStyle` to make some changes but the problem is that i cannot see it, I don't know whether it is hidden or unable to edit.

I am pretty sure that `ItemsStyle` could be found at `Style Library`  but it's now shown in it as shown in this image:

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/QhnpL.png

But I cannot find it. Please help me!