It would be better to put the media query for medium devices on the top of large devices queries because it is better to go from mobile to desktop queries in a crescent sequence
Kindly change the nav menu links so they can be accessed with the keyboard
The text of the alt image of the first project maybe could be more descriptive if changed from "drop" to "water drop", this way readers would have a better understanding
-It could be better to have only one nav for navigation in order to make it easier to implement a responsive menu with javascript.
-Kindly put all images in one folder.
-Descriptive names are better to make your code more readable, so it's a good idea to change the name of your sections.
-It would be better if your project be smaller in the mobile version.