sakura/templates/yuuno/settings/appearance.userpage.twig

<!--div class="bbcode" id="userPagePreview" style="max-height: 500px; overflow-y: auto; background: #C2AEEE; box-shadow: inset 0 0 1em 1em #D3BFFF;">
    <noscript>
        <h1 class="stylised" style="margin: 1em auto;">The preview requires JavaScript, enable it.</h1>
    </noscript>
</div-->
<hr class="default" />
<form enctype="multipart/form-data" method="post" action="{{ sakura.currentPage }}" id="userPageEditorForm">
    <input type="hidden" name="sessid" value="{{ php.sessionid }}" />
    <input type="hidden" name="timestamp" value="{{ php.time }}" />
    <input type="hidden" name="mode" value="userpage" />
    <div><textarea name="userpage" id="userPageEditor" placeholder="[header]Welcome to my userpage![/header]" class="inputStyling" style="width: calc(100% - 12px); height: 400px;">{% if user.page %}{{ user.page }}{% else %}[header]Welcome to my userpage![/header]{% endif %}</textarea></div>
    <div class="profile-save">
        <input type="submit" value="Save" name="submit" class="inputStyling" />
        <input type="reset" value="Reset" name="reset" class="inputStyling" />
    </div>
</form>
<script type="text/javascript">
//document.getElementById('userPageEditor').addEventListener('keyup', updateUserPage);

window.addEventListener('load', function() {
    prepareAjaxForm('userPageEditorForm', 'Updating user page...');
});
</script>