material_base-8.x-2.x-dev/themes/material_base_mdc/templates/form/form-element--textarea.html.twig

{#
  MDC doesn't provide "static label" option for textarea, only floating label.
  But it isn't working well in some cases, for example when CKEditor is applied.

  Here is the alternative implementation which is now enabled by default due to accessability reasons.
#}

{% extends "form-element--textarea--static-label.html.twig" %}

{#
  Original implementation with pure MDC experience:

  {% extends "form-element--textarea--floating-label.html.twig" %}
#}