Button in FAQ/Accordion Box

http://mimichong.nyc/main1/ In my website page, in the middle of the FAQ/Accordion Box, I added a button. I want it to open up as a small window like in the Webster does.
http://www.merriam-webster.com/dictionary/happy

Can you please tell me how to control the link to open up with the specific px height and px wide?

See code in the box:

[spacer height=”10px”]

[button link=”” new_tab=”yes” link=http://mimichong.nyc/wp-content/uploads/2014/03/grapes.mp3 special_style=”no” size=”small” three_d=”no” icon=”hb-moon-volume-medium” color=”default”]