It seems like your links are not functioning properly due to incorrect URL encoding. For more information on URL encoding, refer to w3 URL Encoding. As an example, the first link in the initial item appears as:
fichas/300V 15W50 2Lts. Ficha Tecnica.pdf
However, it should be encoded as:
fichas/300V%2015W50%202Lts.%20Ficha%20Tecnica.pdf
The CSS error you're encountering is likely related to the css file jquery-ui-1.8.21.custom.js. Within this file, there is a section that resembles the following:
/* Component containers
----------------------------------*/
.ui-widget { font-family: Lucida Grande, Lucida Sans, Arial, sans-serif; font-size: 1.1em; height: 200px; }
.ui-widget .ui-widget { font-size: 1em; }
.ui-widget input, .ui-widget select, .ui-widget textarea, .ui-widget button { font-family: Lucida Grande, Lucida Sans, Arial, sans-serif; font-size: 1em; }
/*.ui-widget-content { border: 1px solid #a6c9e2; background: #fcfdfd url(images/ui-bg_inset- hard_100_fcfdfd_1x100.png) 50% bottom repeat-x; color: #222222; } */
.ui-widget-content a { color: #222222; }
.ui-widget-header {color: #ffffff; font-weight: bold; }
.ui-widget-header a { color: #ffffff; }
To resolve this issue, try removing the line
.ui-widget-content a { color: #222222; }
. Alternatively, you can override it in your own css file if necessary.