This article was originally published in the DEV Community.
Here's a neat little trick:
You can use the :focus-within
selector to style the parent of a focused element.
That allows you to create some interactive form UI without a single line of JavaScript. Try the example below:
This demo uses :focus-within
, plus the ::before
pseudo-selector and some absolute positioning magic. We'll go through the details but you can check the full source below.
:focus-within
selector + ::before
pseudo-elements + absolute positioning #
All in a single declaration block! Let's have a look at the most important part of this example.
body:focus-within::before {
content: "";
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
background-color: rgba(0, 0, 0, 0.7);
}
body:focus-within
#
This selector will apply styles whenever there is focus... within the body!
Oh, and :focus-within
works with any element. We're sticking with body
only for this example.
You can be creative and come up with .literallyAnyElement:focus-within
and use this selector as you please.
body:focus-within::before
+ absolute positioning #
In our example, that means that whenever any field is focused on the body, a ::before
pseudo-element will be created with those styles:
content: "";
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
background-color: rgba(0, 0, 0, 0.7);
The content: ''
property is required for pseudo-elements and everything else are properties used to create a dark, transparent overlay that fills the whole screen!
Extra stuff to make it work properly #
Keep in mind that you still need to make a couple of tweaks to make the overlay work perfectly.
html,
body {
height: 100vh;
}
This makes sure that the overlay fills the whole screen even if there isn't enough content on the page.
form {
position: relative;
This position: relative;
ensures that the overlay renders below the form.
And that's it for this week's neat little trick. Thanks for reading!
Make sure the check the other tricks in the series and follow me on Twitter if you found any of my articles helpful 😄
EDIT: Make sure to check Andrew's suggestion in the comments below!
Photo by Stefan Cosma on Unsplash