General styling

[lalva224]

• General styling, dark mode. Apply cool gradients and effects Favicon
• Make it responsive to all devices.
• Make sign up and sign in pages modals instead of different pages
• Style Page right after stripe payment
• Loading skeleton using suspense OR CircularProgress whenever loading
• Try to use links instead of button hrefs which are slower (? may not be true)

[lalva224]

Markus