Widen left-hand panel, Jewelry Box theme webapp

[arcetrac]

Is there any way to widen the left-hand panel in the Jewelry Box theme in the Web AppBuilder? I'm using the Jewelry Box theme with the smart editor widget as it is the only theme which allows me edit data in a side panel, and I don't like using the pop up window to enter data, again it's either too small or full screen.

I've tried:

• Exploring the theme customization options in Web AppBuilder.
• Searching the AG Assistant knowledge base for relevant tips.
• Examining the .json file associated with my web app (6000 lines of code and no idea what I'm looking for)

Is there a way to customise this side panel?

I appreciate any insights or suggestions the community can offer.

Screenshot below, I've omitted the text, but you can see how narrow the left hand panel is, not ideal for entering data.