JSFiddle - React, Tailwind, and code Playground

HTML

<div class="bubble" style="border-color: pink; background: pink;">
    <p>Hola Mundo!</p>
</div>

CSS

.bubble {
    margin: 80px;
    padding: 80px;
    position: relative;
}
.bubble:after {
    content: "";
    position: absolute;
   top: -10%;
   left: 20px;
   border-bottom: 20px solid blue;
   border-top-color: inherit;
   border-left: 20px solid transparent;
   border-right: 20px solid transparent;
}