can HTML be used to design all web page

Answer 1

u need css for style and js to interact with the user, u can add more languages but those 3 are the basics for web development

Answer 2

yes... you can design with html but it will be fully static web page

Answer 3

Nobody use only Html for design wev page: Css is inseparable of it ( technically you can do a page without styling, but the result will not be attractive at all ). However, you don't need to learn a lot of Css for use it basically ;)

Someones attempt to avoid use of JS with success: it's often a few hardiest to handle interactivity, but it's possible ( in a certain measure ), and dynamise the behaviour through Css is even preferable ( and not more hard ) to implement that with JS, when it's possible. And it's good practice to avoid or at least limit use of JS, to not penalize users who whatever don't have or desactivate it...

However, JS is useful as fallback, for functionalities improperly supported by browsers ( or older versions of )... or for going even further towards complex web applications instead classic web site ^^