Jquery add attribute doesn't works in submenu

Question

I have menu with submenu and I show submenu using jquery. All menu items clicks adds custom attribute ("data-modal") to body page. This functions works fine in menu items but doesn't works in submenu items (item OBRAS). When i click in OBRAS modal window is LIGHT and when i click in submenu items the modal window background MUST be DARK. I dont know why doesnt works with submenu items. DEBUGGER CHROME doesn't show any error. WEBSITE http://iglesias.coroleu.com/

This is my script:

    jQuery(function ($) {
    $('.activado-obras .children li').click(function() {
        $(this).addClass('active').siblings().removeClass('active');
        $('.activado-obras .children' ).toggleClass('children-1');
    });
    $('.activado-biografia .children li').click(function() {
        $(this).addClass('active').siblings().removeClass('active');
        $('.activado-biografia .children' ).toggleClass('children-1');
    });
    $('.activado-obras').click(function() {
        $('body').attr('data-modal', 'light');  
        $('.activado-obras .children' ).toggleClass('children-1');
    });
    $('.activado-biografia').click(function() {
        $('.activado-biografia .children' ).toggleClass('children-1');
        $('body').attr('data-modal', 'dark');   
    }); 
    $('.escritos').click(function(){
        $('body').attr('data-modal', 'dark');                                   
    });
    $('.videos').click(function(){
        $('body').attr('data-modal', 'dark');                                   
    });
    $('.prensa').click(function(){
        $('body').attr('data-modal', 'dark');   
    }); 
    $('.contacto').click(function(){
        $('body').attr('data-modal', 'dark');           
    });             
    $('.tradicionales').click(function(){
        $('body').attr('data-modal', 'dark');
    });
    $('.tridimensionales').click(function(){
        $('body').attr('data-modal', 'dark');
    });     
}); 

I try this code tu update data attribute from this "question" (Can't update data-attribute value) but doesnt work.

    $('body').data( 'modal', 'dark' );

Thanks