<style>
html, body { margin: 0; padding: 0; } .btn-group{ font-size: 14px; position: relative; } .open>.dropdown-menu{ display: block; } .btn{ padding: 10px 30px; border: 1px #E8940B solid; background: #f1f1f1; } .dropdown-menu{ position: absolute; left: 0; z-index:1000; display: none; min-width: 160px; padding: 5px 0px; margin: 5px 0px; border: 1px #438FF5 solid; text-align: center; list-style: none; background: white; } .dropdown-menu>li{ line-height:35px; white-space:nowrap; }</style>
<body>
<div class="btn-group open">
<button class="btn btn-toggle">按钮</button> <ul class="dropdown-menu"> <li>上海上海1</li> <li>中国中国2</li> <li>哈尔冰3</li> <li>生日快乐4</li> <li>节日快乐5</li> </ul> </div></body>