小编Hà *_*inh的帖子

select {
  overflow-y:scroll;
  height: 200px;
	border: 1px solid #c4c7cc;
	border-radius: 20px;
	margin: 0;
	padding: 10px;
	color: #323232;
	width: 100%;
	transition: border-color 0.25s ease;
	font-size: 12px;
}

select:not([disabled]):hover,
select:not([disabled]):focus {
	border-color: #ff7900;
}

select[disabled] {
	opacity: 0.5;
}

<div>
  <select multiple class="form-control">
    <option>1</option>
    <option>2</option>
    <option>3</option>
    <option>4</option>
    <option>5</option>
  </select>
</div>