No JS Component
Include this snippet directly in your <head> along with adding class .vf-no-js to your <html> (<html class="vf-no-js">).
If JS is enabled in a user's browser, .vf-no-js will be swapped to .vf-js.
This method allows using CSS to conditionally show content.
.vf-no-js .js-is-not-on {
/* SHOW block that says you need js to use this site */
}
.vf-js .js-is-not-on {
/* HIDE block that says you need js to use this site */
}