JSFiddle - React, Tailwind, and code Playground
HTML
<div class="c-select">
<select name="c">
{PHP.c|catselector_selectbox('projects', $this, 'c')}
</select>
</div>
<br><br>
<div>
<select name="c">
<option>Опция 1</option>
<option>Опция 2</option>
<option>Опция 3</option>
<option>Опция 4</option>
<option>Опция 5</option>
</select>
</div>
CSS
.c-select select[name=c] {
display: inline-block;
max-width: 100%;
-webkit-appearance: none;
padding: .375rem 1.75rem .375rem .75rem;
padding-right: .75rem \9;
color: #55595c;
vertical-align: middle;
background: #fff url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAUCAMAAACzvE1FAAAADFBMVEUzMzMzMzMzMzMzMzMKAG/3AAAAA3RSTlMAf4C/aSLHAAAAPElEQVR42q3NMQ4AIAgEQTn//2cLdRKppSGzBYwzVXvznNWs8C58CiussPJj8h6NwgorrKRdTvuV9v16Afn0AYFOB7aYAAAAAElFTkSuQmCC) no-repeat right .75rem center;
background-image: none \9;
-webkit-background-size: 8px 10px;
background-size: 8px 10px;
border: 1px solid #ccc;
-moz-appearance: none;
}
.c-select select[name=c]:focus {
border-color: #51a7e8;
outline: none;
}
.c-select select[name=c]::-ms-expand {
opacity: 0;
}