Live Demo: Bootstrap Simple Modal Login Modal Form

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>Bootstrap Simple Modal Login Modal Form</title>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto|Varela+Round">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js"></script>
<style>
body {
	font-family: 'Varela Round', sans-serif;
}
.modal-login {
	width: 320px;
}
.modal-login .modal-content {
	border-radius: 1px;
	border: none;
}
.modal-login .modal-header {
	position: relative;
	justify-content: center;
	background: #f2f2f2;
}
.modal-login .modal-body {
	padding: 30px;
}
.modal-login .modal-footer {
	background: #f2f2f2;
}
.modal-login h4 {
	text-align: center;
	font-size: 26px;
}
.modal-login label {
	font-weight: normal;
	font-size: 13px;
}
.modal-login .form-control, .modal-login .btn {
	min-height: 38px;
	border-radius: 2px; 
}
.modal-login .hint-text {
	text-align: center;
}
.modal-login .close {
	position: absolute;
	top: 15px;
	right: 15px;
}
.modal-login .checkbox-inline {
	margin-top: 12px;
}
.modal-login input[type="checkbox"] {
	position: relative;
	top: 1px;
}
.modal-login .btn {
	min-width: 100px;
	background: #3498db;
	border: none;
	line-height: normal;
}
.modal-login .btn:hover, .modal-login .btn:focus {
	background: #248bd0;
}
.modal-login .hint-text a {
	color: #999;
}
.trigger-btn {
	display: inline-block;
	margin: 100px auto;
}
</style>
</head>
<body>
<div class="text-center">
	
	<a href="#myModal" class="trigger-btn" data-toggle="modal">Click to Open Login Modal</a>
</div>

<div id="myModal" class="modal fade">
	<div class="modal-dialog modal-login">
		<div class="modal-content">
			<form action="/examples/actions/confirmation.php" method="post">
				<div class="modal-header">				
					<h4 class="modal-title">Login</h4>
					<button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
				</div>
				<div class="modal-body">				
					<div class="form-group">
						<label>Username</label>
						<input type="text" class="form-control" required="required">
					</div>
					<div class="form-group">
						<div class="clearfix">
							<label>Password</label>
							<a href="#" class="float-right text-muted"><small>Forgot?</small></a>
						</div>
						
						<input type="password" class="form-control" required="required">
					</div>
				</div>
				<div class="modal-footer justify-content-between">
					<label class="form-check-label"><input type="checkbox"> Remember me</label>
					<input type="submit" class="btn btn-primary" value="Login">
				</div>
			</form>
		</div>
	</div>
</div>     
</body>
</html>