必填项

<>
<span className='label required'>这是一个必填项</span>
<input required type='text' />
<style jsx>{`
.label::after{
	content: ":";
	font-size: 20px;
	color: black;
	margin-left: 5px;
	margin-right: 5px;
}
.required::before{
	content: "*";
	font-size: 20px;
	color: red;
	margin-left: 5px;
	margin-right: 5px;
}
`}</style>
</>