Facing issues with custom block — image upload and font not visible on mobile

Hi everyone,
I’ve created a custom chat-style block in my course, similar to a conversation layout (like the one in my attached screenshot).

I’m facing two issues:

1. Image Upload Issue:
   Currently, I have to upload profile images individually for each chat bubble (for example, one for each message).
   Is there a way to upload it once for each character (like a master image) and have it automatically appear for all messages from that person?
2. Font Not Visible on Mobile:
   On phone screens, the font becomes too small or sometimes disappears — it’s not scaling properly in responsive view.
   Is there any setting or CSS trick to fix text visibility or scaling for mobile in custom blocks?

I’m building this in Rise 360 (please change if you’re using Storyline).
Any suggestions or examples would be super helpful!

Thanks in advance 🙏