fully dinamic chart from json data

for the hover behavior in the bars... I guess: I started using data-attributes, but then I realized that it would not be necessary if I previously put the values ​​in the innerhtml of each tag. Should I have gone that route? there is any way to show/hide a label by hover the sibbling element? it could be make it without javascript? Overall i enjoy a lot this project, and was a way to remember something of json. I really appreciate yours comments! Thanks in advance!!