css not showing with htaccess

[eluser]frietkot[/eluser]
Hi,

I use a css file in my view file with this code

Code:

<?=link_tag('style.css');?>

and it works perfect.
But when i use my htaccess file

Code:

RewriteEngine on
RewriteCond $1 !^(index\.php)
RewriteRule ^(.*)$ index.php/$1 [L]

That works too but all my images and styles are not shown.

What is wrong?