In modern web development space utilization and beauty site taken much consideration while designing. So Recent web development modal popup for login so popular. I made modal popup design using Twitter Bootstarp..
Please refer my latest tutorial on Bootstrap Login Modal Popup.
Step 1:
Create index.html file, and add following css and js files in it.
<link rel="stylesheet" href="css/bootstrap.min.css"/> <link rel="stylesheet" href="css/font-awesome.min.css"/> <link rel="stylesheet" href="css/style.css" /> <script src="js/vendor/modernizr-2.6.2.min.js"></script> <script src="js/vendor/jquery-1.10.2.min.js"></script> <script src="js/vendor/bootstrap.min.js"></script>
Step 2:
Now add folowing html markup for maodal popup in the index.html file.
<div class="container-fluid">
			<div class="row">
				<div class="col-md-offset-4 col-lg-offset-4 col-md-4 col-lg-4">
					<h1 class="text-center">Twitter Bootstrap Modal Login Popup</h1>
					<button id='modal-launcher' class="btn btn-primary btn-lg" data-toggle="modal" data-target="#login-modal">
					  Please sign In - Modal
					</button>
				</div>	
			</div>
		</div>
<div class="modal fade" id="login-modal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
	<div class="modal-dialog">
    	<div class="modal-content">
      		<div class="modal-header login_modal_header">
        		<button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
        		<h2 class="modal-title" id="myModalLabel">Login to Your Account</h2>
      		</div>
      		<div class="modal-body login-modal">
      			<p>Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required</p>
      			<br/>
      			<div class="clearfix"></div>
      			<div id='social-icons-conatainer'>
	        		<div class='modal-body-left'>
	        			<div class="form-group">
		              		<input type="text" id="username" placeholder="Enter your name" value="" class="form-control login-field">
		              		<i class="fa fa-user login-field-icon"></i>
		            	</div>
		            	<div class="form-group">
		            	  	<input type="password" id="login-pass" placeholder="Password" value="" class="form-control login-field">
		              		<i class="fa fa-lock login-field-icon"></i>
		            	</div>
		            	<a href="#" class="btn btn-success modal-login-btn">Login</a>
		            	<a href="#" class="login-link text-center">Lost your password?</a>
	        		</div>
	        		<div class='modal-body-right'>
	        			<div class="modal-social-icons">
	        				<a href='#' class="btn btn-default facebook"> <i class="fa fa-facebook modal-icons"></i> Sign In with Facebook </a>
	        				<a href='#' class="btn btn-default twitter"> <i class="fa fa-twitter modal-icons"></i> Sign In with Twitter </a>
	        				<a href='#' class="btn btn-default google"> <i class="fa fa-google-plus modal-icons"></i> Sign In with Google </a>
	        				<a href='#' class="btn btn-default linkedin"> <i class="fa fa-linkedin modal-icons"></i> Sign In with Linkedin </a>
	        			</div> 
	        		</div>	
	        		<div id='center-line'> OR </div>
	        	</div>																												
        		<div class="clearfix"></div>
        		<div class="form-group modal-register-btn">
        			<button class="btn btn-default"> New User Please Register</button>
        		</div>
      		</div>
      		<div class="clearfix"></div>
      		<div class="modal-footer login_modal_footer">
      		</div>
    	</div>
  	</div>
</div>
Step 3:
Here css styles for the modal popup.
body{
    color: #888888;
    font-family: 'Bree Serif',serif;
    font-size: 16px;
    min-height: 2000px;
}
.login_modal_footer{margin-top:5px;}
.login_modal_header .modal-title {text-align: center;font-family:'Philosopher',sans-serif; }
.form-group{position: relative;}
.form-group .login-field-icon {
    font-size: 20px;
    position: absolute;
    right: 15px;
    top: 3px;
    transition: all 0.25s ease 0s;
    padding-top: 2%;
}
.login-modal{
    width:100%;
    padding-bottom:20px;
}
.login_modal_header, .login_modal_footer {background: #00BB64 ;color:#fff;}
.modal-register-btn{margin: 4% 33% 2% 33% ;width:100%;}
.login-modal input{height:40px; box-shadow: none; border:1px solid #ddd;}
.modal-body-left{float:left; width:50%; padding-right:4%; border-right:4px solid #ddd;}
.modal-body-right{float:right; width:47%;}
.login-link{padding:0 20%;}
.modal-social-icons{padding:0 10%;}
.facebook, .twitter, .google, .linkedin {width:100%;height:40px; padding-top:2%; margin-top:2%;}
.modal-icons{margin-left: -10px; margin-right: 20px;}
.google, .google:hover{background-color:#dd4b39;border:2px solid #dd4b39;color:#fff;}
.twitter, .twitter:hover{ background-color: #00aced; border:2px solid #00aced;color: #fff;}
.facebook, .facebook:hover{background-color: #3b5999; border:2px solid #3b5999;color:#fff;}
.linkedin, .linkedin:hover{background-color: #007bb6; border: 2px solid #007bb6; color:#fff;}
#social-icons-conatainer{position: relative;}
#center-line{position: absolute;  right: 265.7px;top: 80px;background:#ddd;  border: 4px solid #DDDDDD;border-radius: 20px;}
.modal-login-btn{width:100%;height:40px; margin-bottom:10px;}
#modal-launcher{margin: 30% 0 0 30%; }
h1{border-bottom:5px solid #00BB64;}
