textarea-auto-size Demo

The content of the <textarea> element is empty

<textarea class="js-textarea-auto-size"></textarea>

Default value is set for the content of <textarea> element

<textarea class="js-textarea-auto-size">text
text
text
text
text
text
text
text
text
text</textarea>

Vertical writing

<textarea class="js-textarea-auto-size"></textarea>

writing-mode: vertical-rl

writing-mode: sideways-rl