How to link to section in same static page?
You need to use Jquery and a tiny bit of css.

Javascript 

$('.page-scroll').click(function() {
    $('.cat-pages').toggle('slow');
});


css

.cat-pages { display: none; }


JS FIDDLE DEMO EXAMPLE

edit: 

To use jquery in drupal you use 

(function ($) {
    // code goes here
})(jQuery);


go to drupal/sites/all/themes/YourTheme/

look for your  theme.info file and add this line in there

scripts[] = js/myscript.js


Then go drupal/sites/all/themes/YourTheme/js and create myscript.js file. 

put this inside it

(function ($) {
    $('.cat-pages').hide();
    $('.page-scroll').click(function() {
        $('.cat-pages').toggle('slow');
    });
})(jQuery);


If the above doesn't work, try

(function ($) {
    $(document).ready(function () {  
    $('.cat-pages').hide();
            $('.page-scroll').click(function() {
                $('.cat-pages').toggle('slow');
            });
    }); 
        })(jQuery);


PS: 

Don't worry about .cat-pages { display: none; }css anymore, since I added the hide in the jquery $('.cat-pages').hide();