I hope you are doing great!
I want to add a hover darken effect on the three images in this link: http://expedicionextrema.gt/inicio/
Similar to the hover effect in this template: http://www.templatemonster.com/es/demo/51191.html
I can only use CSS or JS, but I am not really sure how I can do it.
I hope you guys can help by pointing in the right direction :wink: