<div class="container">
    <div class="row">
        <div class="col-lg-12" style="margin-top:100px; text-align: center">
            
            <a href="<?php echo site_url('face');?>" class="btn btn-lg btn-primary" role="button">Facebook</a>
            &nbsp; &nbsp;
            <a href="<?php echo site_url('google');?>" class="btn btn-lg btn-danger" role="button">Google+</a>
    
        </div>
    </div>
</div>