College Physics Answers needs a compelling website design. -- fixed budget

I sell screencast video solutions to textbook physics problems from the OpenStax College Physics for AP Courses textbook: [login to view URL] Our audience consists of students in first year university/college and grades 11 and 12 at high school, mostly located in the United States. I am also the creator of https://www.giancolianswers.com. The front page has a sample video which is similar in concept to what I'm making for College Physics Answers. The website should convey some or all of the following. College Physics Answers: - is the authoritative source for learning physics problem solving skills - will help you get the best marks in your physics course - will save you time with learning physics This is an educational website. It needs to be really easy to use and navigate. Calls to action, and fonts, need to be easily legible. I think it's helpful to imagine that the target audience consists of over-worked students eagerly scanning the internet for help that will make their job easier and faster, and they'll look at College Physics Answers for maybe only 3 seconds before moving on to the next Google link unless something catches their attention. Catching their attention by effectively conveying what College Physics Answers will offer them is the goal of this design. Attached below are mockups with comments for each of the 5 pages. Please don't let the mockups prevent you from making suggestions. They're just ideas, and I'm really interested in your ideas. Please don't hesitate to ask any questions. Please keep in mind that about 30% of users will visit this site with mobile browsers, so I will want to know how designs should adjust for narrow widths. Typically, horizontally adjacent design components will stack vertically on narrow widths. 1) Home page: I'm not sure if the "FEATURES" section presents features in the best way. The concept I was exploring was to have a screenshot of a solution which is cropped to display the portion being described (one of "final answer", "full video solution", "downloadable pdf", and "community"). The crop is overlaid on the top and bottom with a rectangle with gradient opacity. Would icons be nice to have to the left of each heading? A stock photo somewhere showing a successful looking college or high school student who a prospective customer might aspire to be could be helpful, if that fits into your design. 2) Choose a chapter page: What I have in mind is to use the Bootstrap 3 port of the Bootstrap 4 card component: [login to view URL] 3) Plans: The is part of the sales funnel, and it needs to convert users to paying customers. 4) Sign up page: it uses the Braintree Web Dropin UI v3. 5) Single Solution - subscriber: This is a single solution shown to a paying customer. This is the product students are paying for. The video has an HD 16:9 aspect ratio. 6) Single Solution - anonymous user: This is a single solution as displayed to a non-paying student. It has the question and the final answer, but the video thumbnail has an overlay linking to the plans page and a sample solution from the same chapter that is displayed in full. The video will not be playable, and the downloadable PDF isn't displayed. Comments are displayed. 7) My Subscription tab: This is the tab on the user profile where students and teachers can manage their subscription. I am particularly interested in knowing the color scheme I should use. While the colors of the textbook covers shown on the home page mockup can not be changed, I'm open to changing the logo color if you advise. Bootstrap 3 calls for values for the following colors: $brand-primary: $brand-success: $brand-info: $brand-warning: $brand-danger: These colors are primarily used for button background colors, but might also be used for headings, or whatever you advise. Please let me know what hex color codes I should use above.