Floating box with animation. Demo: https://codepen.io/shakil/pen/BadEgwQ

index.html

<div class="info"></div>

script.js

document.querySelector( '.info' ).onmouseover = function ()
{
	this.style.opacity = 1;
}
document.querySelector( '.info' ).onmouseout = function ()
{
	this.style.opacity = 0;
}

style.css

.info
{
	opacity: 0;
	transition: opacity 1s;
}