1.add html file.

index.html

<!DOCTYPE html>
<html>
<head>
<title>form validation&alt;/title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.10.0/css/all.min.css"
integrity="sha512-PgQMlq+nqFLV4ylk1gwUOgm6CtIIXkKwaIHp/PAIWHzig/lKZSEGKEysh0TCVbHJXCLN7WetD8TFecIky75ZfQ==" crossorigin="anonymous" />
<link rel="stylesheet" type="text/css" href="style.css">

</head>
<body>
<div class="container1">
<div class="header1">
<h2>Create Account</h2>
</div>
<form id="form" class="form1">
<div class="form-control1">
<label for="username">Username</label>
<input type="text" placeholder="Username" id="username" />
<i class="fas fa-check-circle"></i>
<i class="fas fa-exclamation-circle"></i>
<small>Error message</small>
</div>
<div class="form-control1">
<label for="username">Email</label>
<input type="email" placeholder="Email" id="email" />
<i class="fas fa-check-circle"></i>
<i class="fas fa-exclamation-circle"></i>
<small>Error message</small>
</div>
<div class="form-control1">
<label for="username">Password</label>
<input type="password" placeholder="Password" id="password"/>
<i class="fas fa-check-circle"></i>
<i class="fas fa-exclamation-circle"></i>
<small>Error message</small>
</div>
<div class="form-control1">
<label for="username">Password check</label>
<input type="password" placeholder="Password two" id="password2"/>
<i class="fas fa-check-circle"<</i>
<i class="fas fa-exclamation-circle"></i>
<small>Error message</small>
</div>
<button>Submit</button>
</form>
</div>
<div class="social-panel-container">
<div class="social-panel">
<p>Created with <i class="fa fa-heart"></i> by<br>
<a target="_blank" href="#">infotech bangla</a></p>
<button class="close-btn"><i class="fas fa-times"></i></button>
<h4>Get in touch on</h4>
<ul>
<li>
<a href="#" target="_blank">
<i class="fab fa-discord"></i>
</a>
</li>
<li>
<a href="#" target="_blank">
<i class="fab fa-twitter"></i>
</a>
</li>
<li>
<a href="#" target="_blank">
<i class="fab fa-linkedin"></i>
</a>
</li>
<li>
<a href="#" target="_blank">
<i class="fab fa-facebook"></i>
</a>
</li>
<li>
<a href="#" target="_blank">
<i class="fab fa-instagram"></i>
</a>
</li>
</ul>
</div>
</div>
<button class="floating-btn">
Get in Touch
</button>
<script type="text/javascript" src="script.js"></script>
</body>
</html>
2.add css file.

style.css

* {
box-sizing: border-box;
}
body {
background-color: #e8e8e8;
font-family: 'Open Sans', sans-serif;
display: flex;
align-items: center;
justify-content: center;
min-height: 100vh;
margin: 0;
}
.container1 {
background-color:
#fcfcfc;
border-radius: 5px;
box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
overflow: hidden;
width: 400px;
max-width: 100%;
}
.header1 {
border-bottom: 1px solid #f0f0f0;
background-color: #f7f7f7;
padding: 20px 40px;
}
.header1 h2 {
/* color: #4e5053*/
margin: 0;
text-align: center;
}
.form1 {
padding: 30px 40px;
}
.form-control1 {
margin-bottom: 10px;
padding-bottom: 20px;
position: relative;
}
.form-control1 label {
display: inline-block;
margin-bottom: 5px;
}
.form-control1 input {
border: 2px solid #f0f0f0;
border-radius: 4px;
display: block;
font-family: inherit;
font-size: 14px;
padding: 10px;
width: 100%;
}
.form-control1 input:focus {
outline: 0;
border-color: #777;
}
.form-control1.success input {
border-color: #2ecc71;
}
.form-control.error input {
border-color: #e74c3c;
}
.form-control1 i {
visibility: hidden;
position: absolute;
top: 40px;
right: 10px;
}
.form-control1.success i.fa-check-circle {
color: #2ecc71;
visibility: visible;
}
.form-control1.error i.fa-exclamation-circle {
color: #e74c3c;
visibility: visible;
}
.form-control1 small {
color: #e74c3c;
position: absolute;
bottom: 0;
left: 0;
visibility: hidden;
}
.form-control1.error small {
visibility: visible;
}
.form1 button {
background-color: #07a63f;
border: 2px solid #07a63f;
border-radius: 4px;
color: #fff;
display: block;
font-family: inherit;
font-size: 16px;
padding: 10px;
margin-top: 20px;
width: 100%;
}
/* SOCIAL PANEL CSS */
.social-panel-container {
position: fixed;
right: 0;
bottom: 80px;
transform: translateX(100%);
transition: transform 0.4s ease-in-out;
}
.social-panel-container.visible {
transform: translateX(-10px);
}
.social-panel {
background-color: #fff;
border-radius: 16px;
box-shadow: 0 16px 31px -17px rgba(0,31,97,0.6);
border: 5px solid #001F61;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
font-family: 'Muli';
position: relative;
height: 169px;
width: 370px;
max-width: calc(100% - 10px);
}
.social-panel button.close-btn {
border: 0;
color: #97A5CE;
cursor: pointer;
font-size: 20px;
position: absolute;
top: 5px;
right: 5px;
}
.social-panel button.close-btn:focus {
outline: none;
}
.social-panel p {
background-color: #001F61;
border-radius: 0 0 10px 10px;
color: #fff;
font-size: 14px;
line-height: 18px;
padding: 2px 17px 6px;
position: absolute;
top: 0;
left: 50%;
margin: 0;
transform: translateX(-50%);
text-align: center;
width: 235px;
}
.social-panel p i {
margin: 0 5px;
}
.social-panel p a {
color: #FF7500;
text-decoration: none;
}
.social-panel h4 {
margin: 20px 0;
color: #97A5CE;
font-family: 'Muli';
font-size: 14px;
line-height: 18px;
text-transform: uppercase;
}
.social-panel ul {
display: flex;
list-style-type: none;
padding: 0;
margin: 0;
}
.social-panel ul li {
margin: 0 10px;
}
.social-panel ul li a {
border: 1px solid #DCE1F2;
border-radius: 50%;
color: #001F61;
font-size: 20px;
display: flex;
justify-content: center;
align-items: center;
height: 50px;
width: 50px;
text-decoration: none;
}
.social-panel ul li a:hover {
border-color: #FF6A00;
box-shadow: 0 9px 12px -9px #FF6A00;
}
.floating-btn {
border-radius: 26.5px;
background-color: #001F61;
border: 1px solid #001F61;
box-shadow: 0 16px 22px -17px #03153B;
color: #fff;
cursor: pointer;
font-size: 16px;
line-height: 20px;
padding: 12px 20px;
position: fixed;
bottom: 20px;
right: 20px;
z-index: 999;
}
.floating-btn:hover {
background-color: #ffffff;
color: #001F61;
}
.floating-btn:focus {
outline: none;
}
.floating-text {
background-color: #001F61;
border-radius: 10px 10px 0 0;
color: #fff;
font-family: 'Muli';
padding: 7px 15px;
position: fixed;
bottom: 0;
left: 50%;
transform: translateX(-50%);
text-align: center;
z-index: 998;
}
.floating-text a {
color: #FF7500;
text-decoration: none;
}
@media screen and (max-width: 480px) {
.social-panel-container.visible {
transform: translateX(0px);
}
.floating-btn {
right: 10px;
}
}
3.add js file.

script.js

const form = document.getElementById('form');
const username = document.getElementById('username');
const email = document.getElementById('email');
const password = document.getElementById('password');
const password2 = document.getElementById('password2');
form.addEventListener('submit', e => {
e.preventDefault();
checkInputs();
});
function checkInputs() {
// trim to remove the whitespaces
const usernameValue = username.value.trim();
const emailValue = email.value.trim();
const passwordValue = password.value.trim();
const password2Value = password2.value.trim();
if(usernameValue === '') {
setErrorFor(username, 'Username cannot be blank');
} else {
setSuccessFor(username);
}
if(emailValue === '') {
setErrorFor(email, 'Email cannot be blank');
} else if (!isEmail(emailValue)) {
setErrorFor(email, 'Not a valid email');
} else {
setSuccessFor(email);
}
if(passwordValue === '') {
setErrorFor(password, 'Password cannot be blank');
} else {
setSuccessFor(password);
}
if(password2Value === '') {
setErrorFor(password2, 'Password2 cannot be blank');
} else if(passwordValue !== password2Value) {
setErrorFor(password2, 'Passwords does not match');
} else{
setSuccessFor(password2);
}
}
function setErrorFor(input, message) {
const formControl = input.parentElement;
const small = formControl.querySelector('small');
formControl.className = 'form-control error';
small.innerText = message;
}
function setSuccessFor(input) {
const formControl = input.parentElement;
formControl.className = 'form-control success';
}
function isEmail(email) {
return /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>
()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/.test(email); }
// SOCIAL PANEL JS
const floating_btn = document.querySelector('.floating-btn');
const close_btn = document.querySelector('.close-btn');
const social_panel_container = document.querySelector('.social-panel-container');
floating_btn.addEventListener('click', () => {
social_panel_container.classList.toggle('visible')
});
close_btn.addEventListener('click', () => {
social_panel_container.classList.remove('visible')
});