当用户选择字段时,表单上每个输入字段的占位符值应该消失,但事实并非如此.Doctype是HTML5.
http://dailyspiro.com/index.html
<input required type="text" name="user-first-name" id="user-first-name" placeholder="First Name" class="text ui-widget-content ui-corner-all decorative-icon icon-user" />