What's this?

This pen was created to demonstrate how one way a developer can go about creating a form with some fancy text/password inputs using :focus-within and :has() *.

The next section contains a rough idea as to how the CSS code would look if :has() were implemented.

* This is an emulation of :has() powered by EQCSS .

CSS Code what-if

This section contains a rough idea as to how the CSS code would look if :has() were supported.

[...] (See CSS Editor, scroll to /* Demo Login Panel */)

.input_container:focus-within > input,
.input_container > input:valid {
	margin-top: 1.2em;
}
.input_container:focus-within > span,
.input_container:focus-within > a,
.input_container:has(> input:valid) > span,
.input_container:has(> input:valid) > a {
	font-size: .8em;
	opacity: .5;
}
.input_container:focus-within > a,
.input_container:has(> input:valid) > a {
	opacity: 1;
	pointer-events: auto;
}

Notes & References

Very late into putting this pen together, I realized the pen became a little unnecessary to make as I rewrote a number of lines to use :focus-within instead of an emulation of :has(> input:focus) . Despite this, the emulated :has() rulesets moreorless exist to keep the .input_container 's title text and link in place as long as the input sibling that's generally sitting next to them isn't empty. Silver lining? It also makes for an awesome demo showcasing what :focus-within ( which is supported outside of Edge) can do.