Five CSS tricks that repeatedly saved my a**e, why need more?Monday, January 22nd, 2007 at 11:57 pm
Getting a lot of hits from the 53 CSS-Techniques You Couldnâ€™t Live Without post on Smashingmagazine I realised I don’t really need a lot of those (although a lot are cool). Instead let me share with you CSS techniques that saved my a*** whenever I had to create a layout using CSS or proving those wrong that claimed layout tables cannot be replaced.
None of these are new, and many will be the comment that people knew about this, but I can safely say that knowing about the following and some scripting allows me to create almost any of the fancy 53 techniques mentioned.
Tabula Rasa – the global whitespace reset
In October 2004 I found Andrew Krespanis’ global whitespace reset on his still (to me ) beautiful site leftjustified. The idea behind it is so simple, it is ingenious: as every browser out there has an own mind when it comes to rendering styles with a built-in stylesheet, you can overcome all the differences with a simple * selector that undoes everything the browser did. You reset margins and paddings to zero, remove list-type and even set a standard font size. After using global whitespace reset you have a clean slate to start from.
Making the absolute relative
Absolute positioning can be dead handy when you need to align different elements horizontally. You just position one to right and give the other a right padding of the width of the first one, voila – columns. It gets problematic when you need to have other content above the multi column one and you don’t know how high that one will be. The trick is to have both in a parent element and position this element relative – the absolute element will be positioned in relation to this one and not the browser window. Douglas Bowman is the man to thank for this one and that it doesn’t work on MSIE 5.02/Mac is not really causing me any headache.
Containing the float
The problem with the second trick is that if the absolutely positioned column is not the longer one of the two it’ll spill out of the containing element, which is why it is better in a case where you have no clue about the column length to float both of them. The problem when you float them is that the containing element has no height whatsoever. The workaround is to set 100% width on the container and float it to the left, too. Make sure to put a clear:both on the following element on the page
Sliding doors of CSS
Another Bowman trick was Sliding doors or in short using a large background image and clever positioning to allow for expandable navigation elements. As I am not caring much for browsers that should not be supported any longer, I normally tend to use one massive background image and position it in the different elements accordingly as shown in the flexible CSS menu tutorial.
Using background-position to cut down on images and avoid caching issues
Another permutation of this solution is using one background image for several page elements and use dimensions and background-position to only show the relevant part of the image. This technique, christened CSS Sprites (rubbish, they aren’t 24×21 pixels like real sprites) by Dave Shea allows you to cut down load time (as you don’t need to resolve the URL and load lots and lots of images) and avoids nasty flickering on rollovers that MSIE had.
Out of the screen, out of the mind with off-left
Sometimes you need to show and hide content or you need to have content that is only available to visitors that have CSS disabled (the latter should never become a habit, it is a dirty hack and you know it). This is where the off-left technique comes in handy. Instead of using display:none you position the element far off the screen with a negative horizontal and vertical value. Screenreaders will still read them out, but CSS enabled browsers don’t show them at all.
I love CSS, I like most browsers, I just don’t think that we need to overcomplicate matters.