Change the size of Chatbox

[lal....@yahoo.com]

I've used <aside> to change the position of the Chatbox. But I wish to make it look nicer. When I adjust the height in the <aside>, it only increases the length of the background instead of the chatbox (as in the attached image). Is there a way to make the chatbox look nicer?

I'm relatively new to otree. If it's difficult to do this. Please be specific in your answer. Thank you very much!