我想在输入字段有效或无效时选择标签。我如何实现这一目标?
<div class="amplify-flex" style="flex-direction: column;">
<fieldset class="amplify-flex" style="flex-direction: column;">
<span class="amplify-visually-hidden">
<legend>Sign in</legend>
</span>
<div class="amplify-flex amplify-field amplify-textfield">
<label class="amplify-label" for="amplify-id-:r4:">Email</label>
<div class="amplify-flex amplify-field-group amplify-field-group--horizontal" data-orientation="horizontal">
<div class="amplify-field-group__field-wrapper amplify-field-group__field-wrapper--horizontal" data-orientation="horizontal"><input aria-invalid="false" autocomplete="username" class="amplify-input amplify-field-group__control" id="amplify-id-:r4:" required="" type="text" name="username"></div>
</div>
</div>
.amplify-field:has(input:valid) label
查找具有有效输入字段并且具有子标签的所有类(.amplify-field)
感谢@CBroe!