Question

all i need is some client side code jQuery or JS that will alter the divs style after X seconds

like visibility : hidden; OR max-height : 50px;

or switch the class \ id of the DIV ( preferred )

Answer 1

Use setTimeout

setTimeout(function(){
  // Change the style here... If using jQuery, it turns
  $('#my_divs').css({'visibility':'hidden', 'max-height':'50px'})
  // or
  $('#my_divs').addClass('my-custom-class');
}, x_seconds);