In the CSS2 era, text shadows could only be created by using the positioning property "position" to overlap two elements, or by using the DropShadow filter, which, however, only worked in IE. Although the IE browser does not yet support CSS3, it is an inevitable trend for all browsers to support CSS standards. Once they all support CSS3, achieving text shadow effects will become very simple. However, not all browsers currently support CSS3 features; block shadow effects are only supported by Webkit browsers, especially Safari and Chrome. Therefore, here you only need to write the prefix "-webkit".