Time Tracking Dashboard using HTML, CSS, and JS

Is my HTML structure okay? I used grid for this project and I am wondering if the way I made this would be the same if I ever have to work on a large scale grid? A friend of mine has also suggested I try doing this with Flexbox. I'd like to know your thoughts on using Flexbox for this project.

Is the way I name my CSS alright and what are your thoughts on the arrangement? I'd also like to ask about how you find the responsiveness.

Lastly, how was the JS part of my code? I feel like there was an easier way to put the contents of the JSON file into JS but I just don't know what it is. This is my first time working with a JSON file and I'd like to know the best practices and a more efficient way of working with them!

Thanks!