You can also try this:
And also run code snippet!
CSS and then HTML:
#select-category {
font-size: 100%;
padding: 10px;
padding-right: 180px;
margin-left: 30px;
border-radius: 1000000px;
border: 1px solid #707070;
outline: none;
-webkit-appearance: none;
-moz-appearance: none;
background: transparent;
background-image: url("data:image/svg+xml;utf8,<svg fill='black' height='34' viewBox='0 0 24 24' width='24' xmlns='http://www.w3.org/2000/svg'><path d='M7 10l5 5 5-5z'/><path d='M0 0h24v24H0z' fill='none'/></svg>");
background-repeat: no-repeat;
background-position-x: 100%;
background-position-y: 5px;
margin-right: 2rem;
}
_x000D_
<select id="select-category">
<option>Category</option>
<option>Category 2</option>
<option>Category 3</option>
<option>Category 4</option>
<option>Category 5</option>
<option>Category 6</option>
<option>Category 7</option>
<option>Category 8</option>
<option>Category 9</option>
<option>Category 10</option>
<option>Category 11</option>
<option>Category 12</option>
</select>
_x000D_