CSS3

You’ve probably seen the ad for them on the right hand side by now if you’ve visited this site before, but we thought it would be good to introduce them in a post as well: a warm welcome to FreshBooks!

FreshBooks let’s you send out invoices through a great online interface, has a nice API, automatically accept all sorts of payments, etc. etc. etc.! I seriously suggest checking out their tools if you do a lot of invoicing, especially as they are NOT expensive.

When you’re at it, check out the great design of their site… It’s one of the best looking commercial sites I’ve seen in a while.

I recently posted a preview of the CSS3 colour module on my own blog, but avoided using any actual examples. This was because of the things that have been implemented, the true power isn’t really seen using a simple example. With opacity and the HSLA/RGBA colour models, any elements that have been coloured just look like they fade to a lighter tint if there is only a white background behind it. Support for SVG colour keywords has also existed for a long time, just without being accepted by the validator.

To show the true flexibility of CSS3 colour, I had to build a more complex example with overlapping elements. I also added a number of other CSS3 properties to show case them while I was at it (Why not?). Due to using a lot of transparency, there are a number of issues with Minefield, where it crawls to a hault then eventually stops responding. This may only be a issue with the Mac build or my hardware, so your mileage may vary. There shouldn’t be any issues with using webKit, except for a number of bugs that I seem to have uncovered. Most of these were hi-lighted in my previous post.

Without further ado, here is the example for you to try out (warning large background image). It is based on a loose mock-up of a Mac OS X Leopard style interface. I needed a background image, so took a wallpaper from Michael Palin’s great Sahara series. The photo is copyright Basil Pao and is of a mother and her child in Tabelot, Niger.

Because the example was designed to showcase the various colour values, I’ve mixed between using opacity, HSL, HSLA, RGB, RGBA (both hex and percentage) and keywords. In a real production site I’d have avoided this and stuck with the same colour models where appropriate. I tend to use keywords myself as they are easier (for me) to remember. HSL (and by extension HSLA) would be very useful when greater control over the colour is needed, but at the current moment it isn’t supported enough to be used. The correct RGB value would have to be used anyway to act as a fallback colour.

The example showcases the difference between HSLA/RGBA and opacity. If you hover over the File or Go menus, I’ve added a sub menu that has opacity applied too it. When hovering over a menu item that is displayed over the white title bar behind it, you’ll notice the text is more white than the text with the mud background behind. This is because opacity is set on the foreground and well as the background. for elements that have been styled using HSLA or RGBA on the background colour, such as the faux-window title bars, contents area and menu bar, retain fully opaque text. While the difference isn’t too great with this example, there can be cases where the difference is quite obvious. It also allows things like just the shadows to have transparency.

I’ve included quite a lot of other CSS3 into the mix. There is liberal use of box-shadow to give the allusion of depth on the windows and title bar. Rounded corners have been added to windows. There is an issue with rounded corners, where if overflow is set (which adds scroll bars) then the corner with the scroll bar ignores the radius (or is displayed behind it). I moved the overflow to a div inside the faux-windows to avoid this problem. I’m not sure how browsers can be fixed to avoid this problem without the spec changing to accommodate things like scroll bars. resize was added to both faux-windows, but there is issues with each element inside the window being resizable independently in Safari, and not being able to resize it smaller (the later wasn’t an issue in earlier builds).

One of the big compatibility issues with current browser support is the difference between overflow using multi column layout. In Safari it doesn’t respect the setting of having two columns, by adding extra columns to the right of the visible columns. This seems smart at first as it avoids the issue of having to scroll to the bottom of the first column and back up to the start of the next column, however it is generally harder to scroll horizontally than vertically. You can also imagine if a height was set and overflow wasn’t used then it could push any content to the right of the columns out of view, such as a right hand side bar. Minefield just uses the two specified columns and makes the content as long as needed. This has issues as you get the scrolling problem mentioned previously. This will be a usability annoyance. My only suggestion is that a column height can be set, and when all available space is taken up without scrolling, a column break is inserted and columns of the same width and height are repeated below until the content runs out. There would have to be some way to specify the vertical column gap though. This would solve the readability issue, a one block of columns could be read at one time, and it will stop and important right sided content (or left in rtl layouts) from being pushed off the screen.

The next CSS3 used was background-size. This was set at 100% so that no matter how big or small the browser window is, all the background image is shown (overflow:hidden; had to be added as the very latest versions of WebKit add scroll bars, unlike previous versions). This currently only works in WebKit. While most of this works fine in WebKit (if you ignore the bugs), one thing that only works in Opera and KHTML is the menu separators. Instead of adding mark-up such as a br I used the nth-child selector to select the exact element where the separator should go, and added the appropriate margin, border and padding. Without there being an element to group related list items, I though this was the best way to go about it, plus it was another excuse to show off more CSS3. Finally I used a attribute selector to grey out the print menu option (or any option in the menu with a URL of #). This is a bit of a hack to demonstrate the technique, but you can see how it could be useful in the real world.

The great power I see coming with CSS3 is that this example looks fairly complex and flashy, yet only uses one image (the background image), and the mark-up is very brief. I could have used even less mark-up and ID/Class attributes, but they were added for semantic meaning. The problem is more that the browser has to do much more processing to work out things like the transparencies so there can be performance issues, especially on older hardware. One can expect that performance will be tuned as support for the new properties are included in final releases.

I haven’t seen any official announcement yet, but it seems that KHTML and WebKit are to unfork. According to the linked article – which also provides an interesting history of the two engines – there is a bit of work to be done, such as importing KHTMLs advanced CSS 3 features, before the unforking happens, but it should mean that WebKit gains a lot more active developers, which can only be good news.

Since the idea of CSS2.2 was raised, there’s been some discussion as to what it should encompass, who should be responsible for the spec, and what it should be called; here’s what I think:

First, it doesn’t matter what it’s called. Whether it’s referred to as CSS2.2, CSS2.1+, CSS3 Interim, or whatever, makes no difference. It doesn’t need to have a name at all; the important thing is that we have it.

Second, it doesn’t need to be an official recommendation from the W3C; in fact, it may be easier if it’s not. The optimal solution would be communication between developers and browser manufacturers, and – crucially – between the browser manufacturers themselves. What’s needed is an agreement as to which features are implemented, and to make sure those features are implemented in the same way; a de facto standard.

Finally, what feature should it include? For me, it has to be the elements which have already been implemented and tested in at least one browser for an amount of time sufficient for developers to have used them.

The most-requested feature is multiple background images; if you’re going to have that, background clip, origin and size would be wanted too. Border images would also be useful, as would an agreement on implementation of border radius.

Opacity, and with it RGBA and HSLA, box shadow, and text shadow would round off the decorative declarations.

Even if those few could be agreed on, a lot of workarounds could be avoided.

I would have said that multi-column layouts were less urgent, but as they are already part of the Gecko engine and about to be introduced in Safari 3, it seems that that should be part of the standard. Media queries would be pretty necessary as we move into the mobile era, too.

Nothing I’ve mentioned above would be unrealistic; most have already been implemented in at least two current or imminent browsers. As they are available, why are we being kept waiting before we can use them? Think of all the extraneous markup we could be freeing ourselves from!

Come on, browser makers: open up lines of communication and get talking to one another; float the ideas on your company blogs, see what your readers have to say. There’s a whole big community of developers who love to download nightly builds and test new features, and are hungry to improve their pages.

While preparing an example of using the colours specified in the CSS3 Colour module, I come across something after Minefield (the nightly builds of Firefox 3) updated itself. It now supports the resize property from the Basic user interface module.

Unfortunately, Minefield loads, then freezes and eventually doesn’t respond when trying to use this. This is unsurprising of a nightly release, and was likely due to the other CSS3 properties I was using on the example. The strange thing however is that the examples on the css3.info resize preview page do not work at all.

I decided to strip out a lot of the extra styles and content that I was using, and have an example where resize works both in WebKit and the latest Gecko builds. As this is part of another example that isn’t quite finished yet, there are a number of bugs, which may or may not be my fault. There are also a number of styles which probably don’t need to be there, but are part of a bigger example, that will be coming soon. I just wanted something quick that would show this in action. Feel free to suggest any improvements.

You can check out the resize example here.

So what are the issues? In the example I wanted to make a faux window, much like a desktop application window. The whole window should be resizable as one block. For this I placed the resize on the app-window div. The main contents of the window had to be scrollable when there is too much contents for the size of the window, but the rest of the contents shouldn’t scroll, such as the title bar (a h2 element). Therefore I put the scroll on the contents div.

In Safari there is a problem where both the h2 title bar and the main contents resize independently of each other. There doesn’t seem to be a way to resize the whole containing div where the resize is set. In Firefox this works correctly (or at least how I expected it to work). In Safari the content also can’t be resized smaller that the initial value of the div. This wasn’t an issue in an earlier build I was using while developing the example.

Minefield can be resized down to the minimum size and width requested, but it only resizes correctly horizontally. The div resizes vertically but the containing content div doesn’t resize at all. This may be a bug of mine as the contents seems to break out of the container slightly at the bottom. I haven’t had time to look into this.

One strange thing about Minefield’s support for resize is that it adds a cross-hair icon that allows one to move the contents around the page. This works correctly, unlike the resize, but I can’t find anywhere in the spec which specifies this should be allowed when using resize and it isn’t expected behaviour, or at least I wasn’t expecting it, and I didn’t specify that the div should be moveable. It would be nice to be able to specify this with a different property however.

Also, as I use a Mac, I expect the content to be only resizable from the resize widget on the bottom right hand corner (for better or worse). Minefield ignores this and has its own controls, which can’t be styled as far as I know. I also can’t remove the resize controls after clicking out of the resizable content. They stay until the page is reloaded. As resize has probably just been implemented, it is expected that their will be a number of bugs like this however, so things should improve as more people test out this and other CSS3 properties. Resize with HSLA/RGBA and overflow: scroll; is particularly buggy for instance.

I’m working on the original example, that I’ll post here at a later date, along with an updated version of the overview of the CSS3 Color Module that I posted on my personal blog recently. I guess I’ll have to report the bugs I’ve found to the appropriate places, unless it turns out I have bugs in my code instead.

I mentioned earlier this year a tutorial which shows how to use CSS 3 selectors to enhance hyperlinks. Of course, you don’t need to limit yourself to just the href attribute; with CSS 3 selectors, you can use the same technique for any tag which has an attribute. I’m going to give a couple of quick examples, which will output the following result (of course, you’ll need a browser better than IE6 to see them!):

• Home
• Download a PDF
• En Français

All icons are from the fantastic collection at famfamfam.com.

The first list item uses the general attribute selector to look for any tags with an accesskey attribute and display an icon to alert users to its presence:

#test_selectors a[accesskey] {
background: url('icon_key.gif') no-repeat 0 50%;
text-indent: 20px;
}

The second item looks for links with a type attribute value of ‘application/pdf’ (you do mark up links to documents using the type attribute, right?) using the exact attribute selector, then inserts an icon advising you of the destination document:

#test_selectors a[type='application/pdf'] {
background: url('file_acrobat.gif') no-repeat 0 50%;
text-indent: 20px;
}

Finally, if you have a multi-language site you can link to another version using the lang attribute with the value of that language, then use the language attribute selector to apply that country flag:

#test_selectors a[lang|='fr'] {
background: url('fr.gif') no-repeat 0 50%;
text-indent: 20px;
}

As always there is much more you can do with the selectors; if you use or develop this idea on your site, post links here for us to see.

Now that got your attention, didn’t it? You’ve probably never seen a site where Safari has a market share of 84%… Well neither had I. Until I looked at the browser stats for this site… I just had to share it with you all:

The Short Answer:

None of it.

The Slightly Longer Answer:

I’m in the process of updating the Preview area at the moment (sneak preview), and what’s immediately apparent is the low level of implementation of the new CSS 3 features across the major browsers. As IE6 is still the most widely-used browser, roughly 50% (and, slowly, falling) of the market has next to no CSS 3 support at all. A sobering thought.

With IE7 introducing support for attribute selectors, roughly 50% of the market can use those. You will still have to provide fall-back support for IE6, however, either with conditional comments or through graceful degradation.

Next most-widely implemented property is opacity; with support in all the key browsers other than IE, perhaps 25% of site visitors will see this effect if you use it. Again, make sure that your designs degrade gracefully if tempted to add this to your code.

After that, you can more or less forget it. The properties in the Backgrounds and Borders module have patchy implementation in browsers, and almost all use browser-specific prefixes, which you probably want to steer away from in a production environment as they are subject to change (see the border-radius conflict as a good example of why they are tricky to implement).

text-shadow should gain support from Safari 3 and Opera 9.5, but even being generous that’s only around 5-10% of the market. Most of the other properties have little or no cross-browser support.

What You Can Do About It:

Get behind Andy Budd’s ‘CSS 2.2’ idea. Think about it. If you have a blog, discuss it there. Write to browser manufacturers and the W3C. We’re putting together a campaign website to promote the idea, so get in touch with us and offer support.

We want – no, need – these new properties, to do away with many of the non-standard or non-semantic solutions we have to use today to provide complex solutions for simple problems. CSS 3 provides many of those solutions, but they won’t be implemented cross-browser until they become standard; that can be via the W3C, or a de facto standard agreed by browser manufacturers. But however that standard is made, it won’t happen unless there’s concerted pressure from the development community.

I’ve written a number of posts about CSS3 on my personal blog, so when I was asked to write on CSS3.info I jumped at the chance. To get the quick disclaimer out of the way, my day job is working for Opera Software as their Chief Web Opener. Any thoughts are my own, and any use of CSS3 properties doesn’t imply that they will or will not be supported by Opera in an upcoming release, unless otherwise explicitly stated.

With that out of the way, I was discussing the difference between opacity and RGBA in the office, and thought that it would be useful to write an example showing what the later can be useful for. In the main part, using RGBA is different from opacity, as the transparency only applied to the property you are setting the colour of, while opacity sets the transparency of the entire element. For example, setting opacity on a p element will set text as well as the background colour to the setting chosen, while setting RGBA will only make the background colour transparent, and not the text, if background-color property is used. I decided that overlaying a text block over an image would show this quite well, so I’ve knocked up an example using this to style a figure contain within an article. This example can be found here.

To mark-up the figure, I wrapped the img and the p containing the caption in a div element. While this wasn’t strictly needed, I feel like the figure is a division of the page, and so give some semantic meaning and convenient grouping of the figure’s components. I gave it the class name of figure as suggested in Dan Cederholm’s blog post on marking up figures and Chris Messina’s post on a similar topic. I then added a class of caption on the caption, to state explicitly what the element contains.

The first important point to note when using CSS3 is that only the very latest browser versions support any given feature, if any do at all. Therefore as Peter points out in the previous post, it is important to use graceful degradation. this is especially important when using RGBA colour values, as browsers are instructed to ignore the CSS statement if it doesn’t understand the Alpha channel part. It doesn’t fallback to just using the Red Green and Blue channels. In the example used here, the figure caption has been set to red with a alpha channel value of 0.6, using background-color: rgba(255, 0, 0, 0.6);. A value of 1 would mean the colour would be fully opaque, while 0 would be fully transparent. For browsers that don’t support RGBA, there would be no background colour at all, and the text would be illegible. To solve this, a regular background colour is given, in this case background-color: red;. This has to be included before the statement using RGBA, so that it will be overridden by browsers that do support RGB with Alpha channel.

To get the caption to overlay the image, the paragraph in question was set to use position: relative;, and given left and top values that position the element in the correct position; in this case the bottom right corner of the image. A positive z-index value was given to ensure that it was displayed above the img element. I was tempted to use em values for the sizing and placement of the caption and the padding/margin of the figure, but as the image uses pixels for it’s height and width, it made the cross browser placement of the caption inconsistent across the browsers tested (Opera, WebKit, Minefield). Even using pixels, Minefield (current nightly of Firefox 3) is 1 pixel out on the vertical placement compared to Opera and WebKit. I’m sure there is probably a better way to place the element than what I’ve used in this example.

As this blog is about CSS3 I added a couple more features. I gave the caption a slight shadow (okay, not strictly CSS3) using text-shadow: 2px 2px 2px black; (This works in Opera Kestrel and Safari) and gave the whole figure a slight 3D effect by specifying a shadow around it. This was done using box-shadow. In truth no browser supports this without prefixes but Safari 3 supports it using -webkit-box-shadow. I also initially added a CSS3 selector to style the first line of text in the article as bold, using .content p:first-of-type:first-line. Unfortunately Safari 3 currently has a bug where it will apply this to every p and not just the first one, while Firefox totally ignores it as it doesn’t support the first-of-type selector. Safari will probably fix this bug before version 3 is released as I noticed they’ve just fixed a similar bug with using p:first-of-type:first-letter, but as I can predict when the first paragraph will come in this example (after the figure) and it works across each of the three browsers I tested, I just settled on using .figure+p:first-line. If anyone has any questions comments or has any better way of doing things, then feel free to leave a comment.

Graceful degradation means that your Web site continues to operate even when viewed with less-than-optimal software in which advanced effects don’t work.

Fluid Thinking, by Peter-Paul Koch

With CSS 3 so tantalisingly close (and yet so far away!), it’s fun to play around with some of the new cosmetic features. In fact, we can even start to implement them on websites – as long as provision is made for users with older browsers.

I’ve made a quick example of a horizontal, tabbed navigation using CSS 3, which degrades gracefully for older browsers.

Here’s the markup:

<ul>
<li><a href="">One</a></li>
<li><a href="">Two</a></li>
<li><a href="">Tre</a></li>
<li><a href="">Qua</a></li>
</ul>

The CSS is quite lengthy, so view the source of the example page and you’ll get some idea of what I’ve done.

If you’re using IE6, you’ll see just a row of plain, grey boxes which don’t animate when you mouse over them. IE7 and Opera users get a slightly better experience, with the text going white when hovered:

li:hover a { color: #fff; }

Firefox and Safari 2 users get it better still, with border-radius and multiple backgrounds respectively supplying curves to the tabs:

li {
url('corner_fff_topleft.png') no-repeat top left,
url('corner_fff_topright.png') no-repeat top right;
-moz-border-radius-topleft: 25px;
-moz-border-radius-topright: 25px;
}

It’s when you get to Konqueror (and, presumably, Opera 9.5), however, the new styles really kick in; use of the nth-child declaration allows for alternating colours, and text-shadow give a slight illusion of depth when hovered:

li:nth-child(1n) { background-color: #9f9; }

li:nth-child(1n):hover { background-color: #0c0; }

li:nth-child(1n):hover a { text-shadow: 2px 2px 2px #000; }

li:nth-child(2n) { background-color: #6f6; }

li:nth-child(2n):hover { background-color: #090; }

This was a very quick and easy example, but I’m sure you can imagine much more creative uses for graceful degradation. It’s a useful technique if you have the time to implement it, and comes in very useful when trying to persuade people to upgrade to a better browser: “If you think that website looks good now, take a look at it on my computer!”