Don’t Style Headings Using HTML5 Sections

Styling headings is either a deceptively complex problem, or maybe the design of CSS made it appear complex when it need not have done.

When styling headings (or really anything) we want three big goals to be met:

  1. DRY – Do not repeat yourself. We want to set headings once and never (ok, rarely!) repeat those font styles or selectors. This will make our site easier to maintain.
  2. Predictable – The heading should look the same no matter where on the page it is placed. This will make creating new pages and content easier.
  3. Keep specificity low and selectors as simple as possible. This will help with performance and keep the site from growing more and more tangled over time.

The html5 section tag is weird. It dramatically changes the way we use headings. It also changes the way browsers and assistive technologies are meant to interpret those headings. The spec says:

“The section element represents a generic section of a document or application. A section, in this context, is a thematic grouping of content, typically with a heading.”
The HTML5 Spec

The spec goes on to warn us that sections are not really meant to be used just because you want to attach a style a particular piece of content:

“The section element is not a generic container element. When an element is needed for styling purposes or as a convenience for scripting, authors are encouraged to use the div element instead. A general rule is that the section element is appropriate only if the element’s contents would be listed explicitly in the document’s outline.”
The HTML5 Spec

People seem to have blocked out this last (very important) bit, so I’ll reiterate. Sections aren’t really meant to be used by CSS for style purposes (at least not *only* for styles). So, if sections aren’t meant to be used to make my headings purty, why do they exist? They change the way the browser and assistive technologies interpret the importance of a heading relative to the other headings on the page. To understand this, you need to know a bit about the pitfalls of the way headings have been written up until now.

HTML Headings

Think back to the outlines you wrote for term papers in high school. Each bit of a website is meant to be like that, each heading corresponds to a piece of that outline, and you know when you go up or down a level by the heading level chosen. H2 is down one level from H1. And h6 is down four levels from H2.

THE TITLE IS THE H1
I. Big roman numerals are the H2s
   A. This is an h3
   B. This is also and h3
      i. Now we have an h4
      ii. And another h4
II. Big roman numerals are the H2s
III. Big roman numerals are the H2s
IV. Big roman numerals are the H2s

The trouble is, on a modern website or web app, this model isn’t a really natural fit. Especially if a site “mashes up” content from sources they don’t control (say for example adding a twitter feed to a blog), they may not be able to set the heading levels used by the mashup content. In this case, most developers, just include the new content, and the outline gets a little murkier.

A murky outline may be somewhat normal, because I’d take it a step further and say that, on most modern websites, the idea that the site has much in common with a high school term paper outline is a bit of a stretch — The section element tries to bridge the gap between the w3c’s outline view of the web and the way developers are really building sites. The section element essentially reorders the heading tree so that whatever headings are used, if they are wrapped in a section element, they will be made to fit in with other content on the page. They need only be internally consistent within each section.

<h2>Me on the web...</h2>
<h1>My Twitter Feed</h1>
<ul class="tweets">
 <li>Mmmm, cornflakes.</li>
 <li>Something inane...</li> 
</ul>
<p><a href="more.html">More stuff on the web</a></p>

HTML5 Headings & Section Elements

If you wrap it in a section, the browser will interpret it as one level down from it’s parent heading.

<h2>Me on the web...</h2>
<section>
<h1>My Twitter Feed</h1>
<ul class="tweets">
 <li>Mmmm, cornflakes.</li>
 <li>Something inane...</li> 
</ul>
</section>
<p><a href="more.html">More stuff on the web</a></p>

The section element also makes it clear that the list of tweets belongs to the Twitter feed, and the more link does not. This makes content more portable, which is okay — even if it maybe isn’t that important. However, it does seem to be confusing people about how they should style their headings. I think this bit of the spec might be confusing people:

Notice how the use of section means that the author can use h1 elements throughout, without having to worry about whether a particular section is at the top level, the second level, the third level, and so on.
The HTML5 Spec

This has lead people to think that they should only ever use h1s (which, is a fair interpretation of the working group’s note). However, lots of people have taken it a little too far because they didn’t read the second quote [1], where it says additional section elements shouldn’t really be used only to apply CSS styles. Admittedly a subtle difference, but important! Section elements are meant to help the browser figure out what level the heading really is, but not necessarily to decide how to style it. By tying styles to browser heading level interpretation, developers (trying to implement html5 from the spec) are ending up with selectors that look like this:

h1{font-size: 36px}
section h1{font-size: 28px}
section section h1{font-size: 22px}
section section section h1{font-size: 18px}
section section section section h1{font-size: 16px}
section section section section section h1{font-size: 14px}
section section section section section section h1{font-size: 13px}
section section section section section section section h1{font-size: 11px}

(Note: This is vastly simplified as I’ve only included sections and not the other sectioning elements like articles or asides. This is a more realistic, real life code sample.)

Let’s see how well this meets our goals:

Q: What if, semantically speaking, you need to add an additional section to a bit of html?

It will unintentionally change the way your headings look. If it is high enough on the document tree it could change your entire page. That seems badly unpredictable.

Q: What happens if the design calls for a 14px heading in a part of the site that is only nested two sectioning contents deep?

To make it work with the existing code, you would need to add additional unnecessary section elements. The spec pretty clearly states that section elements are not meant to be added just to change styles. Plus, that is just kind of gross.

Q: What if we create another rule that duplicates the 14px property value pair?

section.special section h1 {font-size:14px}

This clearly isn’t DRY. We’re repeating the code to set the font-size to 14px, and our specificity is starting to get weird. If we want a normal two-section deep heading (22px) we now can’t have it in the special section. We also can’t reuse the new rule anywhere else. Continue in this direction for a while on a project and you can end up with hundreds or even thousands of heading declarations. Eek! This isn’t meeting our stated goals at all.

(For more info about how this can get out of control, check out this video on how our current methods for styling headings are leading to bad outcomes.)

So, how do we style headings in an HTML5 world?

The answer is right there in the spec, next to the place where we learned to use only H1s. We shouldn’t use sectioning elements for styling. We should let them do the job they were designed for, which is sorting out the document tree, and solve styling issues another way that meets our goals better: with simple reusable class names that can be applied to any of our headings no matter how deep they may be in the sectioning content.

I recommend abstracting site wide headings into classes because then they are portable, predictable, and dry. You can call them anything you like. Jeremy Keith recommends something like:

.Alpha {}
.Beta {} 
.Gamma {} 
.Delta {} 
.Epsilon {} 
.Zeta {} 

or

.tera {} 
.giga {} 
.mega {} 
.kilo {} 
.hecto {} 
.deca {} 
.deci {} 
.centi {} 
.milli {} 
.micro {} 
.nano {} 
.pico {} 

I keep it simple with:

.h1{} 
.h2{} 
.h3{} 
.h4{} 
.h5{} 
.h6{} 

It doesn’t really matter what system you choose as long as it is something easy for your team to remember. Then, no matter how many section levels deep your heading is nested, you can make it look just how you want:

<h1 class="giga">Me on the web...</h1>
<section>
  <h1 class="kilo">My Twitter Feed</h1>
  <ul class="tweets">
    <li>Mmmm, cornflakes.</li>
    <li>Something inane...</li>
  </ul>
</section>
<p><a href="more.html">More stuff on the web</a></p>

So now, your twitter feed, from the previous example, can be in the sidebar on an article page, or in the footer of your homepage, and it will still look the way it was designed to. Whether you are using html5 sections or not, you don’t want to repeat code or have it be unpredictable, so I think separating styles from how the browser generates the page outline is just sensible.

UPDATE 9/6: If you truly cannot change the HTML, even to add class names, then the only way to style that bit is to put a wrapper around it with a unique class and use descendent selectors to force the style you want. This should be the exception, not the rule! (Thanks Simon for pointing out that I wasn’t addressing one of the use cases I had talked about above)

<h1 class="giga">Me on the web...</h1>
<section class="tweetfeed">
  <h1>My Twitter Feed</h1>
  <ul class="tweets">
    <li>Mmmm, cornflakes.</li>
    <li>Something inane...</li>
  </ul>
</section>
<p><a href="more.html">More stuff on the web</a></p>

If you would like a far more eloquent walk through all the new html5 elements, get Jeremy Keith’s book HTML5 For Web Designers.

Thanks to Alex Kessinger and Josh for helping me solidify my thoughts around this by bringing up good questions on the CSS Lint Google Group.

CSS Lint open sourced

Nicholas Zakas and I spoke at Velocity a few minutes ago. First we talked about CSS 3 and it’s impact on performance, then we demoed and open sourced CSS Lint! I really couldn’t be more excited (or relieved, I was super duper nervous before this presentation).

CSS Lint is a tool to help point out problems with your CSS code. It does basic syntax checking as well as applying a set of rules to the code that look for problematic patterns or signs of inefficiency. The rules are all pluggable, so you can easily write your own or omit ones you don’t want.

Rules currently tested

  • Parsing errors should be fixed
  • Don’t use adjoining classes
  • Remove empty rules
  • Use correct properties for a display
  • Don’t use too many floats
  • Don’t use too many web fonts
  • Don’t use too may font-size declarations
  • Don’t use IDs in selectors
  • Don’t qualify headings
  • Heading elements should have a consistent appearance across a site.
  • Heading styles should only be defined once
  • Be careful using width: 100%
  • Zero values don’t need units
  • Vendor prefixed properties should also have the standard
  • CSS gradients require all browser prefixes
  • Avoid selectors that look like regular expressions
  • Beware of broken box models

(We’ll allow you to turn off rules that hurt your feelings soon!)

Contribute

Many people have expressed an interest in contributing to the CSS Lint project. We were waiting to have a solid plugable architecture and API before taking contributions. The exciting news is that we are now ready! There are several ways you can contribute:

  1. If you are comfortable with CSS, submit rule ideas. You must provide the rule name, a human readable explanation, browsers affected, and a test case.
  2. If you are comfortable in JavaScript, fork the github project, code up a rule, and submit a pull request. You’ll need to provide all the same documentation requsted in item 1.
  3. If you are comfortable with Node, test out the command line version, submit feature requests.

CSS Lint for Node.js

If you’d like a command line version of CSS Lint, you can install CSS Lint for Node.js using npm using the following:

sudo npm install -g csslint

Once installed, you can pass in any number of CSS files or directories containing CSS files to see the results. For example:

csslint test.css dir_of_css/ test2.css

You’ll receive the same errors and warnings as you would with the web interface.

Welcoming Nicholas Zakas to the Team

I am so very pleased to announce that Nicholas Zakas and I are joining forces to form a consulting duo. Nicholas has spent the last five years defining what it meant to to be a client-side engineer at Yahoo!. He consistently raised the client-side glass ceiling with his commitment to good code and practical solutions. He also literally wrote the book on JavaScript Performance. Like me, Nicholas cares deeply about performance and scalability. And, most importantly, we share a love of finding elegant solutions to hard problems, which we feel makes us a good match.

I’ll let Nicholas speak for himself:

I’ll be … teaming up with my friend (and former Yahoo) Nicole Sullivan to do consulting work. Nicole and I have talked off and on about working together on outside projects after having fun working together on a couple of projects at Yahoo!. Between the two of us, we hope to provide a wide range of front-end consulting services including performance evaluations, general architecture, and of course, JavaScript and CSS. If you’re interested in hiring us, please email projects (at) stubbornella.org.
Nicholas Zakas

Please come see us at Velocity Conference on June 14.

by Trey Ratcliff

Our (CSS) Best Practices Are Killing US

Watch more video from the Top Picks channel on Frequency

Another day, another melodramatic blog post title. ;)

I was prepping to speak at Webstock this year when I realized I didn’t want to give the talk I had proposed. I didn’t want to talk about the Mistakes of Massive CSS, because I realized it went deeper than that. In fact, in most cases, the things we considered best practices were leading to the bad outcomes we sought to avoid. I realized (unpopular though it might be), that we couldn’t make it work out well by trying harder. Each time we start a new project, we think “this time, I’m going to keep the code clean. This time the project will be a shining example of what can be done with CSS.” And without fail, over time, as more content and features are added to the site, the code becomes a spaghetti tangle of duplication and unpredictability.

It is time to let ourselves off the hook. There is nothing we could have done by trying harder. There is no magic juju that some other developer has that we don’t. Following our beloved best practices leads to bad outcomes every. single. time.

What are those flawed best practices?

  • Classitis!
  • Never add an non-semantic element
  • Or, a non-semantic class
  • Use descendant selectors exclusively
  • Sites need to look exactly the same in every browser

Classitis!

How in the world did we even get the idea that some aspects of CSS were good and others evil? Who decided and what data did they use to judge? Did their goals fit our goals? There is nothing wrong with using classes. In almost every case, classes work well and have fewer unintended consequences than either IDs or element selectors.

You should style almost everything with classes. The goal is to find a balance between classes that are too broad and include everything and the kitchen sink and classes that are too narrow. Generally speaking, you don’t want your classes to be so narrow that each one applies a single property value pair. It becomes extremely hard to evolve your design if every item is composed of mini-mixins.

On the other hand, if classes are too broad, you will have duplication. Try to find the middle ground where all the repeating visual patterns can be abstracted. This is hard, but very worthwhile. If you do it, your code will stay clean. You will finally see results from trying harder.

Classes are our friends. Seeing a lot of IDs is actually very bad. Run from this kind of code:

#sidebar #accounts #accountDetails h3{}

Never add non semantic elements

We don’t want to have unnecessarily heavy HTML with a lot of extra elements. On the other hand, adding an extra element can often provide a buffer between two sets of classes that weren’t necessarily coded to interact with one another. For example, I prefer to have the decorative elements of a container completely separated from its content.

Using a paragraph that happens to be inside a rounded corner box to make a corner decoration means that the container can never hold content other than a paragraph. If you want to include a UL you will need to duplicate all those styles. This doesn’t work.

You want your content to be marked up in beautiful HTML that uses a diverse set of tags like P, UL, OL, LI, H1-6, strong, em. Add a few extra wrapper elements to keep your content nicely cordoned off from your containers or separate out decorative flourishes! Your HTML will be clean and your CSS predictable.

Never add non-semantic classes

We absolutely don’t ever want to use classes like “bigRedHeading”, not because it is non-semantic, but because it isn’t future proof. As the design evolves, the CSS needs to keep pace. On the other hand, CSS needs abstractions. We need to be able to solve a particular problem really well, and then allow people to go on using that solution long afterward. Grids for example solve the layout problem. Once they have been implemented on a site, developers can spend time on more important features and stop re-implementing a layout solution over and over. Abstract solutions are necessarily disconnected from the content they happen to contain. This is something we should look for in a solution, not condemn.

The semantics debate has really gone too far. It is useful as a general principal, but often I see standards aware developers trying to stuff in semantics that never existed in the design. If the design didn’t make a distinction between two things visually, why add additional complexity? Classes work much better when we use them to represent visual semantics, rather than keeping them tied to content.

One more point on the topic. Screen readers don’t read class names. It is not an accessibility issue. (Thanks to John Foliot for confirming)

Use descendant selectors exclusively

Never has more terrible advice been given (ok, ok, I exaggerate, but for CSS, this is as bad as it gets). The descendent selector is *only* appropriate between multiple nodes of the same object (say, a tab container and its’ tabs), and even then, only when you are absolutely certain that there will never be any markup changes. Very hard to guarantee, no?

I have had a designer give me a tab container that had one group of tabs to the left and another grouping (usually more simply styled) to the right. In which case, if you had styled the UL using the descendant selector, you would be stuck overriding a bunch of styles you no longer needed. Classes are much much better and can be used in combination with the descendant selector when the nodes belong to the same object.

I guess the only time I use the descendant selector with elements is to style LI, and even then, I often get bitten when someone wants to nest those lists. Better support for the child selector will make that issue easier to fix. Ideally, we don’t want any styles flowing from container to content.

Even with the media block, you might consider putting a class on the media block which sets the styles of the image. It sounds reasonable until you realize that the image is actually its own object. You might have multiple nested media blocks and you will get very weird interactions unless you apply the image style class directly to the image itself.

In the middle layer, you might decide to create one display objects for each of the different types, and that would probably make the objects easier to use, but in the CSS layer, you don’t want to tie it all together like that.

Sites need to look exactly the same in every browser

Forking your design is bad, it makes testing even more complicated, but that doesn’t mean that pixel for pixel a site needs to be exactly the same in every browser. If you try to force the complexities of a modern design onto users of IE6, their user experience will suffer. The site will load slower and reflows and repaints will make the javascript sluggish. IE6 users need a reasonably fast user experience, they do not *need* rounded corners.

Anyway, enough ranting. Please do checkout the slides for Our Best Practices are Killing Us. I hope you find them useful.

Photo by Trey Ratcliff

Automating CSS 3 Gradients

CSS 3 is full of ways to reduce our dependence on background images, one of which is pure CSS gradients. They have several features, which I’m sure designers are salivating over, like multiple color stops, and angled, radial, and linear gradients. Many people had built cool designer-focused tools to make interacting with a somewhat confusing gradient syntax a little easier. The issue for me has been that I’m not a designer. I generally work off of photoshop comps or (when doing big re-architecture projects) the site itself, as if the old version were a design. This means that, for the most part, I was trying desperately to match CSS gradients to an image with zero information about how that image would have been created. Because of my focus on fixing old and broken CSS, the original designer may not even still work at the company.

If you don’t know what I mean, picture me with a color picker going pixel by pixel to try to figure out by hand where the color stops should be and what colors I should use versus extrapolate. Then, for each version, making an image of the gradient I’ve created, blowing it up so I can compare it to the image of the original. Rinse, repeat until I’ve come up with something that kinda, sorta approximates the original. Oh yeah, painful.

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