JSFiddle - React, Tailwind, and code Playground
HTML
<div id=bellnews>
big content<br>
big content<br>
big content<br>
big content<br>
big content<br>
big content<br>big content<br>
big content<br>
big content<br>
big content<br>
big content<br>
</div>
CSS
#bellnews {
position: fixed;
width: 140px;
min-height:100px;
max-height:400px;
background: #fff;
color: #000;
border:1px solid #ccc;
//box-shadow:0 3px 10px 0px #ccc;
//border-top:none;
z-index:3000;
}
#bellnews:before {
content: '';
vertical-align: middle;
margin: auto;
position: absolute;
left: 0;
right: 0;
bottom: 93%;
width: 15px;
height: 15px;
background: #fff;
border-top: 1px solid #ccc;
border-right: 1px solid #ccc;
transform: rotate(-45deg);
-moz-transform: rotate(-45deg);
-webkit-transform: rotate(-45deg);
}