Social Login using PHP and Google

PHP 
In this tutorial we look at how we can add social login to our web application using Google. We do this in PHP.

The login view

<?php
require 'functions.php';
?>
<style>

    .form-heading { color:#fff; font-size:23px;}
    .panel h2{ color:#444444; font-size:18px; margin:0 0 8px 0;}
    .panel p { color:#777777; font-size:14px; margin-bottom:30px; line-height:24px;}
    .login-form .form-control {
        background: #f7f7f7 none repeat scroll 0 0;
        border: 1px solid #d4d4d4;
        border-radius: 4px;
        font-size: 14px;
        height: 50px;
        line-height: 50px;
    }
    .main-div {
        background: #ffffff none repeat scroll 0 0;
        border-radius: 2px;
        margin: 10px auto 30px;
        max-width: 38%;
        padding: 50px 70px 70px 71px;
    }

    .login-form .form-group {
        margin-bottom:10px;
    }
    .login-form{ text-align:center;}
    .forgot a {
        color: #777777;
        font-size: 14px;
        text-decoration: underline;
    }
    .login-form  .btn.btn-primary {
        background: #f0ad4e none repeat scroll 0 0;
        border-color: #f0ad4e;
        color: #ffffff;
        font-size: 14px;
        width: 100%;
        height: 50px;
        line-height: 50px;
        padding: 0;
    }
    .forgot {
        text-align: left; margin-bottom:30px;
    }
    .botto-text {
        color: #ffffff;
        font-size: 14px;
        margin: auto;
    }
    .login-form .btn.btn-primary.reset {
        background: #ff9900 none repeat scroll 0 0;
    }

</style>

<html>
<head>
    <link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
</head>
<body id="LoginForm">
<div class="container">
    <h1 class="form-heading">login Form</h1>
    <div class="login-form">
        <div class="main-div">
            <div class="panel">
                <h2>Admin Login</h2>
                <p>Please enter your email and password</p>
            </div>
            <form id="Login" action="auth.php">

                <div class="form-group">


                    <input type="email" class="form-control" id="inputEmail" placeholder="Email Address">

                </div>

                <div class="form-group">

                    <input type="password" class="form-control" id="inputPassword" placeholder="Password">

                </div>
                <div class="forgot">
                    <a href="reset.html">Forgot password?</a>
                </div>
                <a href="<?php echo get_auth_url();?>" class="btn btn-primary">Login via Google</a>

            </form>
        </div>
    </div></div></div>


</body>
</html>

Notes

README