html弹窗公告

<div class="web_notice" style="
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
background: rgba(0,0,0,0.3);
z-index: 99999;
">
    <div style="position: fixed;top: 50%;left: 50%;width: 550px;background: #FFF;transform: translate(-50%, -50%);border-radius: 40px;padding: 50px 40px;">
        <h3 style="font-weight: bold;text-align: center;font-size: 30px;">网站通知
            <div style="
		font-size: 16px;
		margin-top: 26px;
		line-height: 30px;
		color: #999;">www.xiaohulizyw.com</div>
            <a style="
		display: block;
		background: #98a3ff;
		color: #FFF;
		text-align: center;
		font-weight: bold;
		font-size: 19px;
		line-height: 60px;
		margin: 0 auto;
		margin-top: 45px;
		border-radius: 32px;
		width: 80%;
		" onclick="javascript:document.querySelector('.web_notice').remove()">
                我知道了</a>
    </div>
</div>