input框设置圆角

<style>
.btn{ width: 200px;                                        
      height: 30px;
      background: #ccc;
      border: 1px solid #eee;
      border-radius: 15px;                            //圆角设置
      background:url(./img/)      //背景设置
     }
</style>

<input class="btn" type="button" οnclick="" value="圆角测试">