Tailwind allow us to write the following CSS code:
  .overlay {
    @apply absolute left-0 right-0 bottom-0 bg-black bg-opacity-75;
    top: var(--nav-height);
  }The problem is that @apply isn't a CSS feature. Which means while writing a Svelte component which have such feature:
<div class="overlay" />
<style>
  .overlay {
    @apply absolute left-0 right-0 bottom-0 bg-black bg-opacity-75;
    top: var(--nav-height);
  }
</style>You'll get a bunch of errors like: `semi-colon expected css(css-semicolonexpected)`.
To fix that all you need to do is specifying the language you're writing the style, in our case, postcss:
<div class="overlay" />
<style lang="postcss">
  .overlay {
    @apply absolute left-0 right-0 bottom-0 bg-black bg-opacity-75;
    top: var(--nav-height);
  }
</style>And the error is gone!