Tip Calculator App Using CSS FLEXBOX & JAVASCRIPT

Nice one on completing the challenge but there's a few misses with the functionality;

• The error message gets thrown even if on the input there isn't zero.
• You must also call the function that handles the tip/person & total/person when I click on any tip button to make the functionality a bit easier.
• & also call it if only all of the inputs are not empty other wise you'll get infinity or NaN, like how it's happening right now.