Trends come and trends go. The ones that stick around the longest do so because they solve a particular problem. A trend that's popular right now for that very reason, is sticky elements; elements that behave normally until we scroll, and then maintain their presence on the page somehow.

The trend started with sidebars, but where it’s really grown in popularity is headers. Why? Because headers tend to contain navigation, and persistent navigation is popular with users.

In this tutorial we’ll create a header that sticks to the top of the viewport, but so that it doesn’t interfere with the content, we’re going to minimize it when the user scrolls down the page.

Here’s what it's going to look like when we're done:

If you'd like to follow along with the code, you can download it here.

The HTML

The HTML for our example is really simple, all we need is an h1 inside a header. Below that we have an image to force the page to scroll so that we can test the effect.

<header><h1>Sticky Header</h1></header>
<img src="large-image.jpg" width="782" height="2000" alt="Big Image" />

The jQuery

CSS transitions are the best way of handling the animation portion of our sticky header. All we’re using jQuery for is detecting the scroll position of the window.

When the scroll position of the window is greater than 1—meaning that the user has scrolled downwards—then we want to add the class ‘sticky’ to the header; otherwise we want to remove it (if it’s there).

This means we’ll be able to style the header based on whether the ‘sticky’ class is applied.

$(window).scroll(function() {
if ($(this).scrollTop() > 1){ 
 $('header').addClass("sticky");
 }
 else{
 $('header').removeClass("sticky");
 }
});

The important thing to note is that using jQuery in this way degrades gracefully; if JavaScript is disabled, the navigation will still work, the header will simply be styled in the non-sticky default state.

The CSS

Our CSS is used to style the two different states, the default state, and the ‘sticky’ state; and to transition between the two states.

To start with, let’s add some simple styles that improve the look of the header:

header{
 position: fixed;
 width: 100%;
 text-align: center;
 font-size: 72px;
 line-height: 108px;
 height: 108px;
 background: #335C7D;
 color: #fff;
 font-family: 'PT Sans', sans-serif;
}

Now for the fun part: when the user scrolls down, the ‘sticky’ class will be applied, and we can now style the header differently to reflect that new priority on the page. We also set the position to fixed, so that we're not changing positioning mid-scroll.

There are several things we want to do: first, we want to change the size so that it uses up less screen space; we also want to change the color and align to the left so that visually it doesn’t interfere too much:

header.sticky {
 font-size: 24px;
 line-height: 48px;
 height: 48px;
 background: #efc47D;
 text-align: left;
 padding-left: 20px;
}

Naturally, what you do here will depend on the design you’re trying to achieve. You can do just about anything you like.

If you test this now, you’ll see that the header changes as soon as we scroll down.

Now, to animate the change, all we need to do is set a transition on the header, like so:

transition: all 0.4s ease;

Conclusion

Creating this animated header with CSS3 properties and toggling the class with jQuery is extremely simple and adds a ton of UX goodness to your site design.

What’s more, the code degrades gracefully, so there really is no downside to the implementation.