$(function(){
  _center();
  $(window).resize(function(){
    _center();
  })
  var all = $('a','.theme-roller')
  all.click(function(){
    var self = $(this) ,
        css = self.attr('href').substring(1);
        $('body')
        .removeClass('theme-0')
        .removeClass('theme-1')
        .removeClass('theme-2')
        .removeClass('theme-3')
        .removeClass('theme-4')
        .addClass(css) ;
     all.removeClass('active')
     self.addClass('active')
  })
  $('a','.feature-menu').click(function(e){
    $('.feature-item','.features-container').removeClass('active')
    $($(this).attr('href')).addClass('active');
    e.preventDefault()
  });
})
function _center(){
  var div = $('.wrapper'),
  dw = div.width(),
  dh = div.height(),
  w = $(window),
  ww = w.width(),
  wh = w.height();
  div.css({
    top : ( (wh - dh) > 0 ? ((wh - dh) / 2) : 0),
    left : ( (ww - dw) > 0 ? ((ww - dw) / 2) : 0)
  })
}