如何使用css选择器选择父母的兄弟姐妹div [duplicate]

问：

我想在输入字段有效或无效时选择标签。如何实现此目的？

<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>