CSS doesn't work

[RCBonfire]

Hi.

This is my first time with Prestashop and I'm working with 1.6.1.8 version.

This has begun to happen when, yesterday, I made a huge mistake trying to get more knowledge about Prestashop configurations: I set the CACHE as NO.

For a while, I got the HTTP 5000 error when I'd tried to access the website.

After I set the CACHE as YES, I've restored the .htaccess, cleaned the cache in the right way, and now I can access the webpage.

Unfortunately, now I'm facing issues with the css: there are no styles out there. The page doesn't loads the css global or modules styles

 

That is the link for the website: http://anteeo.eclienti.it/prestashop/

 

Then I set  _PS_MODE_DEV_ on defines.inc.php as true, I got the message below mentioned: 

 

Notice: Undefined index: css_uri in /var/www/vhosts/anteeo.eclienti.it/httpdocs/prestashop/cache/smarty/compile/a3/64/e1/a364e1dd58fed225b8f62d49b50dce85e520f2d9.file.header.tpl.php on line 98 Notice: Trying to get property of non-object in /var/www/vhosts/anteeo.eclienti.it/httpdocs/prestashop/cache/smarty/compile/a3/64/e1/a364e1dd58fed225b8f62d49b50dce85e520f2d9.file.header.tpl.php on line 98

 

Any ideas? Someone could help me please?

Thank you guys in advance.