Animated header

<link rel="stylesheet" href="style.css">
<div class="header">
  <h1>Анимационный заголовок</h1>
</div>
<div class="content">
</div>

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: #08009f;
  color:#fff;
  z-index: 1000;
  height: 200px;
  overflow: hidden;
  -webkit-transition: height 0.3s;
  -moz-transition: height 0.3s;
  transition: height 0.3s;
  text-align:center;
  line-height:160px;

}
.header.shrink {
  height: 100px;
  line-height:80px;
}
.header h1
{
  font-size:30px;
  font-weight:normal;
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  transition: all 0.3s;
}

.header.shrink h1
{
  font-size:24px;
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  transition: all 0.3s;
}
.content
{
height:2000px;
}

$(function(){
    var shrinkHeader = 300;
     $(window).scroll(function() {
       var scroll = getCurrentScroll();
         if ( scroll >= shrinkHeader ) {
              $('.header').addClass('shrink');
           }
           else {
               $('.header').removeClass('shrink');
           }
     });
   function getCurrentScroll() {
       return window.pageYOffset || document.documentElement.scrollTop;
       }
   });