Ilya Pasyuk

.header
  height 60px
  background #000
  &--fixed
     position fixed
     left 0
     top 0

$(window).scroll(function() {
  var container = $('.header');
  var status = $(this).offsetTop >= container.height() ? true : false;

  container.toggleClass('.header--fixed', status);
});

$('.myAlert').on('click', function(event) {
	event.stopPropagation();
});

$(document).on('click', function(){
	$('.myAlert').hide();
});

<a class="link" href="#">
	<img class="image"src="http://uploadme.ru/images/2015/04/19/img1.jpg" alt="image-1">
</a>

.link {
	overflow: hidden;
	display: block;
	position: relative;
	z-index: 1;
	width: 300px;
	height: 300px;
	border: 2px solid #e6d3a0;
	border-radius: 20px;
	font-size: 0;
	text-decoration: none;
	background: #777;
}
.image {
	min-width: 100%;
	min-width: 100%;
	-webkit-transition: .5s;
	-moz-transition: .5s;
	-ms-transition: .5s;
	transition: .5s;
}
.link:hover .image {
	-webkit-transform: scale(1.5);
	-moz-transform: scale(1.5);
	-ms-transform: scale(1.5);
	transform: scale(1.5);
}

...
.pipe(jade({
  pretty: true
}))
...