Use the bottom CSS property to add arrow to the top of the tooltip.
Example
You can try to run the following code to add a tooltip with arrow to the top:
<!DOCTYPE html>
<html>
<style>
.mytooltip .mytext {
visibility: hidden;
width: 140px;
background-color: blue;
color: #fff;
z-index: 1;
top: 150%;
left: 50%;
margin-left: -60px;
text-align: center;
border-radius: 6px;
padding: 5px 0;
position: absolute;
}
.mytooltip {
position: relative;
display: inline-block;
}
.mytooltip .mytext:after {
content: "";
position: absolute;
bottom: 100%;
left: 50%;
margin-left: -10px;
border-width: 3px;
border-style: solid;
border-color: transparent transparent blue transparent;
}
.mytooltip:hover .mytext {
visibility: visible;
}
</style>
<body>
<div class = "mytooltip">Keep mouse cursor over me
<span class = "mytext"> My Tooltip text</span>
</div>
</body>
</html>