Home page: image selected based on device screen size, and re-sized...

[PDN777]

Hi,

I'm a newbie, with a bit of HTML experience. I've programmed in Pascal and a bit of Swift (Xcode).

I want to create a home page for a new web site, with the following conditions:

* if the site is loaded by a phone, I want Image 1 to be selected, which will be sized to fill the phone screen;

* if the site is loaded by a tablet, Image 2 will be selected, and again slightly re-sized to fit the particular device;

* if the site is loaded by a computer, Image 3 will be selected, and re-sized to fill the browser window as
it is sized on the person's computer -- so that it fills the entire window of the browser.

If this is possible using a free WordPress website, please instruct me... :-)

If not, please direct me to HTML or CSS code which will allow me to do this (and I will break down
and buy an URL on GoDaddy or wherever).

Thanks so much in advance,

--PDN