JSFiddle - React, Tailwind, and code Playground

HTML

<span>Tooltip</span>

CSS

body {
    padding: 20px;
} 
span { 
  width:140px;
  color: #000;
  background: #fff;
  height: 130px;
  line-height: 130px;
  text-align: center; 
  border-radius: 6px;
  border: 1px solid #ccc; 
    display:block;
    position:relative;
}
span:after {    
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    margin-left: -15px;
    width: 0;
    height: 0;
    border-right: 16px solid #ccc;
    border-bottom: 15px solid transparent;
    z-index: 1;
}
span:before {
       content: '';
    position: absolute;
    top: 50%;
    left: 0;
    margin-left: -13px;
    width: 0;
    height: 0;
    border-right: 16px solid #fff;
    border-bottom: 14px solid transparent;
    z-index: 2;
    margin-top: 1px;
}