Four card feature solution

I didn't know about grid areas, so had to do some googling to arrange the cards. Hopefully that was the right way of doing the card arrangement. I noticed my sizes are consistently off by a little, usually smaller, but I guess that comes with practice. I've tried to open the design photos in photoshop, and via the select tool get the sizes, which somewhat works, but when coding in those measurements in vscode, they seem to be off by a bit, so it takes additional calibration. I also overlay the design photo with the solution and check that way to. If anyone has any tips regarding that, please let me know.