Test CSS Selector in Microsoft Edge Chromium

Today I had the problem of changing an image URL by using CSS in a SharePoint 2016. I added my CSS element to the CSS file and nothing happend. So I asked myself, how can I test my CSS selector? After some research I found an article in Microsoft Docs for the Microsoft Edge Browser:

https://docs.microsoft.com/en-us/microsoft-edge/devtools-guide-chromium/css/reference#select-an-element

My favourite till now is: Open the DEV Tools, go into the console and type:

document.querySelector('<Your selector!>')

Microsoft Edge shows you the selected element and you can experiment with your selector phrase! The result is:

This works in Internet Explorer 11 to:

Here you get the element as text in the console, but no selection in the page.