<select>
<option>選項1</option>
<option>選項2</option>
<option>選項3</option>
</select>

select {
width: 150px;
background-color: #eee;
font-family: Arial;
}

option {
color: #333;
font-size: 14px;
font-weight: bold;
}

select::-ms-expand {
display: none;
}
select {
appearance: none;
-webkit-appearance: none;
-moz-appearance: none;
background: url("down-arrow.png") no-repeat 95% center;
}