style.css

import url('https://fonts.googleapis.com/css?family=Open+Sans&display=swap');
*
{
	
	margin: 0;
	padding:0;
	font-family: 'Poppins', sans-serif;
}
body
{
	display:flex;
	justify-content:center;
	align-items:center;
	min-height:100vh;
	background:#373737;
}
h3
{
	position:relative;
	font-size:20px;
	color:#f9f9f9;
	letter-spacing:1px;
	font-weight:500;
	margin-bottom:5px;
}
#form #email
{
	width:300px;
	background:#292929;
	outline:none;
	border:none;
	padding:10px;
	border-radius:6px;
	color:#fff;
	font-style:18px;
}
#form .inputBox
{
position:relative;
}
#text
{
	display:block;
	color:#000;
	font-weight:300;
	font-style:normal;
	padding:5px;
}
#form.invalid .inputBox:before
{
content:'';
position:absolute;	
right:12px;
top:10px;
width:24px;
height:24px;
background:url(invalid.png);
background-size:cover;
z-index:1000;
}
#form.valid .inputBox:before
{
content:'';
position:absolute;	
right:12px;
top:10px;
width:24px;
height:24px;
background:url(valid.png);
background-size:cover;
z-index:1000;
}