Using pure CSS with CSS-grid

This is my first challenge on Frontend Mentor, and my first project where I had to do everything myself so any feedback would be welcome.

• I had a hard time naming classes and structuring my code .
• I placed media queries right after each relevant rules instead of bundling them up at the end of the style sheet, a bit overkill for a small project like this right?.
• I used mostly 'rem' , 'pixel' is used for break points and things like border, border radius, Is that all right?