Have a look at the feedback I've left on others solutions to this like this one as a lot of the same issues apply to yours: https://www.frontendmentor.io/solutions/html5-css-and-flexbox-aXZTaM1HQ3.
Definitely move the styles out into their own file, try to get the colours to match and you don't need overflow hidden anywhere so remove all those strange commented out lines of code. Also never use em for font size, use rem!
1
