JSFiddle - React, Tailwind, and code Playground
HTML
<div id="toolTip">
<p>i can haz css tooltip</p>
<div id="tailShadow"></div>
<div id="tail1"></div>
<div id="tail2"></div>
</div>
CSS
body {font-family:Helvetica,Arial,sans-serif;}
#toolTip {
position:relative;
}
#toolTip p {
padding:10px;
background-color:#f9f9f9;
border:solid 1px #a0c7ff;
-moz-border-radius:5px;-ie-border-radius:5px;-webkit-border-radius:5px;-o-border-radius:5px;border-radius:5px;
}
#tailShadow {
position:absolute;
bottom:-8px;
left:28px;
width:0;height:0;
border:solid 2px #fff;
box-shadow:0 0 10px 1px #555;
}
#tail1 {
position:absolute;
bottom:-20px;
left:20px;
width:0;height:0;
border-color:#a0c7ff transparent transparent transparent;
border-width:10px;
border-style:solid;
}
#tail2 {
position:absolute;
bottom:-18px;
left:20px;
width:0;height:0;
border-color:#f9f9f9 transparent transparent transparent;
border-width:10px;
border-style:solid;
}