Best location to store css & img

Code:
&lt;?php if (!defined('BASEPATH')) exit('No direct script access allowed');



class Blog extends Controller{

 

    var $base;

    var $css;



  function Blog()

  {

    parent::Controller();

    $this->base = $this->config->item('base_url');

    $this->css = $this->config->item('css');

    $this->load->model('Blog_model');

    

    

  }

  

  function index()

  {

    $data['css'] = $this->css;

    $data['base'] = $this->base;

    $data['title']="Welcome to My Blog | ebottabi.com";

    $data['entries']=$this->Blog_model->get_last_ten_entries(20);

    $data['comments']=$this->Blog_model->commentnum();

    $this->load->view('view', $data);

  }

  

  function gotopost($post_id)

  {

    $this->load->library('validation');

    $data['css'] = $this->css;

    $data['base'] = $this->base;

    $data['title']="Blog Post";

    $data['heading']="Post";

    $data['posts']= $this->Blog_model->getpost($post_id);

    

     $data['getcomments'] = $this->Blog_model->getcomments($post_id);

    $this->load->view('post',  $data);



    

  }

  function add()

  {

    $this->load->library('validation');

    

    $data['css'] = $this->css;

    $data['base'] = $this->base;

    $data['title']="Add Post | ebottabi.com";

    $this->load->view('addpost', $data);

  }

  

  function logout()

    {

        $this->load->model('Admin_model');

        $this->load->library('session');

        $this->load->helper('url');

        

        $user_id = $this->session->userdata('user_id');

        $session_id = $this->session->userdata('session_id');

        $user_id = $this->Admin_model->checkID($user_id, $session_id);

        

        if($user_id != 0)

        {

            $this->Admin_model->logout($user_id);

            $this->session->sess_destroy();

        }

        redirect('/admin', 'refresh');

    }

    

    function insert()

    {

        $this->load->library('validation');

        $data['css'] = $this->css;

        $data['base'] = $this->base;

        $data['title']="Add Post | ebottabi.com";

        $data['heading']="Add Post";

        $rules['title']    = "required";

        $rules['postdate']    = "required";

        $rules['summary']    = "required";

        $rules['post']    = "required";

                

        $this->validation->set_rules($rules);

        

        if ($this->validation->run() == FALSE)

        {   

            $data['message']="Add Post Incomplete!";

            $this->load->view('addpost', $data);

        }

        else{

            $data['message']="Add Post was Successfully ";

            $this->db->insert('posts', $_POST);

            $this->load->view('addpost',$data);

        }

        

    }

     

    function nav()

    {   

        

        $data['css'] = $this->css;

        $data['base'] = $this->base;      

         $data['title']="My Blog CMS Navigation Page";

        $data['heading']="Blog CMS";

        $data['entries']=$this->Blog_model->get_last_ten_entries(20);

        $this->load->view('nav_view', $data);

    }

    

    function comments()

    {

        

        $data['css'] = $this->css;

        $this->load->library('validation');

        $data['base'] = $this->base;      

         $data['title']="Post your comments";

        $this->load->view('comments', $data);

    }

    

    function comment_insert($post_id)

    {

        $this->load->library('validation');

        $data['css'] = $this->css;

        $data['base'] = $this->base;

        $data['title']="Post Your Comments | ebottabi.com";

        $data['heading']="Post Your Comments";

        $rules['name']    = "trim|required|min_length[6]|max_length[12]|xss_clean";

        $rules['email']    = "trim|required|valid_email|xss_clean";

        $rules['comments']    = "trim|required|min_length[6]|max_length[80]";

        $this->validation->set_rules($rules);

        if ($this->validation->run() == FALSE)

        {   

            $data['message']="Your comments Incomplete!";

            $goto=$this->gotopost($_POST['post_id']);

        }

        else{

            

            $comment = $this->Blog_model->insertcomm($_POST);

            $data['message']="Your comments has been Posted!";

            $this->load->view('comments', $data);

            

        

    }    

    

                 

}



    

    }

    







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