Responsive Time Tracker Application

This was absolutely brutal. I didn't understand how to use the .json file as this was the first time working with .json and have no clue to how it works. So I ended up hard coding everything with javascript. I don't even know if I did it right since it was all hard coded rather than dynamic. What would be the best way to change the contents of the tags when the user clicks on the buttons? I used eventlistner and depending on which button, hardcoded it so it will change them. I'm sure there are many better ways.