Single post in Small Addition to the Coding Box

I'm able to do this already on my laptop using chrome. At the bottom of all text fields is a little notch thingie in the corner that allows me to drag the text area in any shape or size I want. I believe most browsers have that now? However! I don't have such an option on mobile and it is a real pain in the behind to try and edit any template on my phone. I would love for this to be implemented somehow in a way that doesn't break how the page fits on mobile. So, support :o