@cfpb/cfpb-design-system/src/elements/cfpb-utilities/fallback/wc-fallback.css

CFPB's UI framework

/*
This fallback CSS assumes a web component that contains a <noscript> fallback,
as well as author-supplied content, and separately has a script to swap the
<noscript> with `<div class="fallback">` if JS is enabled, but the web component
definition is not defined.

Ex.

<cfpb-example-btn hasfallback>
  <!-- author-supplied no-js fallback -->
  <noscript><button>Click this basic button!</button>

  <!-- author-supplied slotted content -->
  Click this fancy button!
</cfpb-example-btn>
*/

/* 1. If JS is disabled, hide everything except <noscript> */
[hasfallback] > :not(noscript) {
  display: none;
}

/* 2. If JS is enabled, but web component definition is not defined, show fallback. */
[hasfallback] > .fallback {
  display: block;
}

/* 3. If JS is enabled and web component definition is defined, operate as normal. */
[hasfallback]:defined > :not(noscript) {
  display: block;
}