PostCSS: Is empty :deep() selector officially supported?

[ByScripts]

I created a table component:

<table class="table">
  <slot />
</table>

With this kind of scoped CSS:

.table {
  /* ... */

  :deep(th), :deep(td) {
    /* ... */
  }

  :deep(th) {
    /* ... */
  }

  :deep(th) {
    /* ... */
  }

  :deep(thead th), :deep(thead td) {
    /* ... */
  }

  /* And so on... */
}

But since it annoys me to add these :deep(...) everywhere, I tried to change the code to this:

.table {
  /* ... */

  :deep() {
    th, td {
      /* ... */
    }

    th {
      /* ... */
    }

    th {
      /* ... */
    }

    thead {
      th, td {
        /* ... */
      }
    }

    /* And so on... */
  }
}

It works well but:

• I don't know if it is officially supported or if it works "by accident"
• I don't know if this could break in the future
• My IDE warns about a "Term expected in :deep()" and I can't open a ticket if it's not officially supported.

Any information on that? Thank you.

[warmthsea]

:deep(table){
      th,td{
          /* ... */
      }
}

[ByScripts]

I'm sorry, my message was really bad and misleading, I updated it.

The component itself is a table component which will apply styles to the children cells.

[karol-bujacek]

Any update/answer?