Create a responsive register / login form which will also has the option to signup/login using google API code example

Example 1: make google api signin php

<?php
require_once 'vendor/autoload.php';
 
// init configuration
$clientID = '<YOUR_CLIENT_ID>';
$clientSecret = '<YOUR_CLIENT_SECRET>';
$redirectUri = '<REDIRECT_URI>';
  
// create Client Request to access Google API
$client = new Google_Client();
$client->setClientId($clientID);
$client->setClientSecret($clientSecret);
$client->setRedirectUri($redirectUri);
$client->addScope("email");
$client->addScope("profile");
 
// authenticate code from Google OAuth Flow
if (isset($_GET['code'])) {
  $token = $client->fetchAccessTokenWithAuthCode($_GET['code']);
  $client->setAccessToken($token['access_token']);
  
  // get profile info
  $google_oauth = new Google_Service_Oauth2($client);
  $google_account_info = $google_oauth->userinfo->get();
  $email =  $google_account_info->email;
  $name =  $google_account_info->name;
 
  // now you can use this profile info to create account in your website and make user logged in.
} else {
  echo "<a href='".$client->createAuthUrl()."'>Google Login</a>";
}
?>

Example 2: google sign in button

<div class='g-sign-in-button'>
    <div class=content-wrapper>
        <div class='logo-wrapper'>
            <img src='https://developers.google.com/identity/images/g-logo.png'>
        </div>
        <span class='text-container'>
      <span>Sign in with Google</span>
    </span>
    </div>
</div>

<style>
        *, *:before, *:after {
            box-sizing: border-box;
        }

        .g-sign-in-button {
            margin: 10px;
            display: inline-block;
            width: 240px;
            height: 50px;
            background-color: #4285f4;
            color: #fff;
            border-radius: 1px;
            box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.25);
            transition: background-color .218s, border-color .218s, box-shadow .218s;
        }

        .g-sign-in-button:hover {
            cursor: pointer;
            -webkit-box-shadow: 0 0 3px 3px rgba(66, 133, 244, 0.3);
            box-shadow: 0 0 3px 3px rgba(66, 133, 244, 0.3);
        }

        .g-sign-in-button:active {
            background-color: #3367D6;
            transition: background-color 0.2s;
        }

        .g-sign-in-button .content-wrapper {
            height: 100%;
            width: 100%;
            border: 1px solid transparent;
        }

        .g-sign-in-button img {
            width: 18px;
            height: 18px;
        }

        .g-sign-in-button .logo-wrapper {
            padding: 15px;
            background: #fff;
            width: 48px;
            height: 100%;
            border-radius: 1px;
            display: inline-block;
        }

        .g-sign-in-button .text-container {
            font-family: Roboto,arial,sans-serif;
            font-weight: 500;
            letter-spacing: .21px;
            font-size: 16px;
            line-height: 48px;
            vertical-align: top;
            border: none;
            display: inline-block;
            text-align: center;
            width: 180px;
        }

</style>