Next.JS responsive Space Tourism website

Hello! I would like some feedbacks, so thank you in advance.

1. What could I do to improve the pages load? They are loading a bit slow.
2. About the background images used on the pages, they seem a bit filtered on the figma files... What could I do to achieve something like that? I tried using backdrop-filter but it didn't work.
3. Following the second question, the crew/technology images seemed to have some kind of filter too, but I couldn't make it work too. What could I do to get this kind of filter?
4. The buttons on the crew pages are a bit small, making a awful experience for smaller device users. Making the buttons bigger or putting the images on a automatic carousel wouldn't make it a better experience?
5. Mobile sidebar just closes when clicking on the "X" button. Making a outside touch close it would be better too, right?

Any other feedbacks about the website would be great too!