Coding isn't my expertise so i'll leave that to someone else, you've done a great job at making it responsive. My comments are all spacing and font-related. You'll find that the sign up button, for example, has a different font-size than the rest of the navbar elements. There's a lot white space in all sections, I recommend you use a container with a width of 1140px. The shadows on the testimonials section are also harsh. Other than that, I think you've done a really great job, keep it up!