<p data-tooltip="Hello, I'm custom tooltip created with CSS and HTML!">Hover me!</p>



<!-- https://albertwalicki.com/solutions/how-to-add-tooltip-in-html -->

/* customizable START */

body {
  min-height: 100vh;
  width: 100%;
  margin: 200px 0;
  font-family: Arial;
}


p {
  padding: 20px 0;
  font-size: 16px;
  cursor: pointer;
  position: relative;
  text-align: center;
}

/* customizable END */


[data-tooltip]:before {
    /* required code */
    content: attr(data-tooltip);
    position: absolute;
    opacity: 0;
    
    /* customizable */
    top:0;
    left:50%;
    transform: translateX(-50%);
    transition: 256ms all ease;
    padding: 10px 20px;
    color: #333;
    border-radius: 5px;
    box-shadow: 0px 6px 21px rgb(0 0 0 / 10%); 
}

[data-tooltip]:hover:before {
    /* required code */
    opacity: 1;
    
    /* customizable */
    background: #fff;
    border-radius: 5px;
    border: 1px solid #ccc;
    top: -50px;
}