make website more responsive for mobile devices

Hello, See this screenshot. I have added letters to the pages. Underneath the matching urls: A: Any course page. For example: https://meestergijs.nl/item/present-simple/ B/C/D: inside a course, no url avaible. but use login creds (see next post) to check. Use same course as shared with A: https://meestergijs.nl/item/present-simple/ E: https://meestergijs.nl/item/wederkerende-voornaamwoorden/ My questions: A: Can I get a clearer overview of the five bars that show amount of people that gave 1-2-3-4-5 stars. Now it's pushed to the side... B: Can I get the yellow navigation bar to be just as weigth as in picture C and D. C/D: How can I delete the empty space? So that the yellow navigation bar is more closely towards the embedded PDF or video. E: This green bar is the bar that you get after completing course. You can click this to start again. Is it possible to make the width smaller so that it fits the screen and the text on it becomes visible? A lot of questions. But very important to me. Thank you! Gijs