<script type="text/javascript">
 $(document).ready(function(){
 $(".tkyy").click(function(event){
    event.stopPropagation(); //停止事件冒泡
   $(".marsk-container").toggle();
 });
 //点击空白处隐藏弹出层
   $("body").click(function(event){
     var _con = $('.tkyy_con');  // 设置目标区域
     if(!_con.is(event.target) && _con.has(event.target).length ==0){ 
      $('.marsk-container').hide();     //淡出消失
     }
  });
 
});
</script>

.marsk-container{background: #FFFFFF; display: none;position: absolute;position: fixed; top: 0; right: 0; left: 0; bottom: 0px; background: rgba(0,0,0,.5); z-index: 10; }

 <div class="tkyy"><span class="mui-icon mui-icon-arrowdown"></span>请选择退款类型 </div>
          <div class="marsk-container">
            <div class="tkyy_con">
            <div class="mui-input-row mui-radio ">
              <label>退运费</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>收到商品破损</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>少件/漏发</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>商品需要维修</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>发票问题</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>收到商品与描述不符</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>商品质量问题</label>
              <input name="radio" type="radio" checked>
            </div>
            <div class="mui-input-row mui-radio ">
              <label>描述问题</label>
              <input name="radio" type="radio" checked>
            </div>
          </div>
          </div>