Time Tracking Dashboard Design

Hi guys, please review what can I improve in my code. I had to go implement a lot of flex inside grid. Not sure if this was expected, but I tried to code the design, but I need to be more familiar with pixel perfect detailing like most of you. Please point out mistakes so that I can improve and also share best-practices to follow for such massive design. It was tough to give time along with my job, but it was fun to implement a brainstorming solution with crunch of time. It might not be the best solution, but I'm glad that it is working.