如何更改背景选项？

/*LANGUAGE PICKER*/

.select_join {
  width: 170px;
  height: 28px;
  overflow: hidden;
  background: url('http://www.freeiconspng.com/uploads/white-down-arrow-png-2.png') no-repeat 144px #141F26;
  border: #FEFEFE 1px solid;
  background-size: 10%;
  /*-webkit-box-shadow: inset 0px 0px 10px 1px #FEFEFE;
	box-shadow: inset 0px 0px 10px 1px #FEFEFE;*/
}

.select_join select {
  background: transparent;
  width: 170px;
  color: #fff;
  border: 0;
  border-radius: 0;
  height: 28px;
  -webkit-appearance: none;
}

.select_join select:focus {
  outline: none;
}

<div style="text-align:center;">
    <br/>
    <div class="select_join" style="margin-left:15px">
        <select name="txtCountry">
            <option value="1">Россия</option>
            <option value="2">Азербайджан</option>
            <option value="3">Украина</option>
        </select>
    </div>
</div>