网页常用弹出居中层后网页的背景颜色变灰特效，这个弹出的图层可随意拖动，并带有关闭按钮功能。
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<title>弹出层居中并可拖拽效果_武鸣人</title>
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//武鸣人网站https://www.wuming.ren 网站很好记住，wuming.ren(武鸣拼音.ren域名后缀)
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<div id="win_wuming_ren"><h2>Hi!武鸣人弹出层居中特效，欢迎光临，觉得不错就收藏本站吧!<span id="close">×</span></h2>记录日常生活点滴，努力是一种状态，与年龄无关，越努力越幸运，越自律越优秀</div>
<center><button>弹出层</button></center>
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