「css技巧」使用hover和attr()定制悬浮提示-demo

<iframe height="400" style="width: 100%;" scrolling="no" title="【CSS：行为】使用:hover和attr()定制悬浮提示" src="https://codepen.io/xugaoyi/embed/vYNKNaq?height=400&theme-id=light&default-tab=css,result" frameborder="no" allowtransparency="true" allowfullscreen="true" loading="lazy"> See the Pen <a href='https://codepen.io/xugaoyi/pen/vYNKNaq'>【CSS：行为】使用:hover和attr()定制悬浮提示</a> by xugaoyi (<a href='https://codepen.io/xugaoyi'>@xugaoyi</a>) on <a href='https://codepen.io'>CodePen</a>. </iframe>