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I recently udpated our Jasmine unit tests to run in Karma ; expanding our browser coverage, adding code coverage reports , and using fixtures for testing DOM manipulation . One of my tests kept failing in IE9, but only when I ran from the console. If I attempted to debug in the browser, everything passed. It turns out that IE9 (at least) needed a few ms to catch it's breath before correctly focusing on the starting element. To do this, I just added a 100ms delay before each test ran (Using Jasmine 2.3). beforeEach(function(done){ loadFixtures('myfixture.html'); // Setting focus in IE requires a delay to work correctly! setTimeout(function(){ done(); }, 100); });

I recently ran into a situation where some of my styles were broken in Internet Explorer 8. What makes this different from all the other times my styles broke in IE8 was that, as far as I could tell, it was correct. Consider the following code: %highlighted { background-color: #ff0; color: #333; } .keyword.is-active { @extend %highlighted; padding: 10px; text-transform: uppercase; } No problem, right? Then why isn't it working? I wasn't sure, until I looked at the compiled CSS and saw something like this: .some-list:nth-child(2n), .is-highlighted, .keyword.is-active { background-color: #ff0; color: #333; } .keyword.is-active { padding: 10px; text-transform: uppercase; } Since IE8 doesn't support the css selector nth-child , it ignores the entire rule . Without looking at the final output, there's no way of knowing if this will happen ahead of time. So what can you do? Well,

In Chris Coyier's recent article, " Fun with line-height! ", he mentions that we often use unitless values for line-height so that it's proportional to the font size. This is only part of the story, and I was reminded of a Stack Overflow question that got me investigating more about how line-height worked with regards to the various CSS units. If you're declaring the line-height on each element, you won't notice any difference. But if you're not crazy and using the first C of CSS (that's 'Cascading', by the way), then the inherited line-height might not work the way you expect. Disclaimer: This is my understanding after doing some research and testing. I may not be completely correct. TL;DR When using a relative unit (em, %), the line-height is calculated based on the font size of the element where the line-height is defined. This line-height is then inherited, unchanged, by each of its descendants. So we end up with a line

I recently had a strange problem after updating SASS. I have a modal dialog with a semi-transparent overlay behind it. For modern browsers, I'm using a CSS transition from rgba(0,0,0,0) to rgba(0,0,0,.5) For older browsers (namely IE8), I'm using some JavaScript to apply the transparency and animate the transition. To make sure the background gets set correctly, I'm using the standard fallback strategy of defining the background as background: rgb(0,0,0); right before the rgba line. This worked fine, until SASS optimized my code by changing background: rgba(0,0,0,0); to background: transparent; The reason? It's 2 characters shorter. Yes, we've now saved 2 bytes of easily compressible text in exchange for breaking my code. Why did it break? Well, if you haven't already figured it out, normally a browser that doesn't support rgba will simply skip that property and move on. But transparent is supported. So now, instead of h