I assume the layout breaks on my setup because I have set the default browser font size to 18px and you're using em's (which are relative to the base font) to define all your font sizes.

Using relative font sizing isn't necessarily bad, but you should make sure that the whole layout is flexible enough. For example, you have set a static pixel height for the speech bubble and "full stack" containers. With a slightly different font setup that can cause the text to overflow (as can be seen in the screenshot above).

Great work this far, I'll bet you can make this a lot better by reading all the feedback in these comments.

FWIW, that's the same problem I was seeing at the top, and I too have my default font size at 18px.

I also see areas overlapping badly alongside the full stack graphic, which apparently you don't in Chrome.

For 2 and 5, I'm guessing it's the same issue that juriga mentioned, as I also have my default font size a little larger. I see the same effect as in juriga's screenshot at the top, and in Firefox I also see a lot of overlapping text in the area alongside the full stack graphic. My defaults are font size 18px, monospace 16px, minimum 10px; maybe that will help you to reproduce the problem.

As for the graphic itself and the accompanying text, as with much of the document, I think the idea could probably work but I'm not wild about the current execution. I won't repeat things others have already said in detail, but FWIW I agree with the people who have suggested that the graphics lack a common visual style and the text sizes lack a clear hierarchy.

I figured the industry experience covered some of this

Yes and no. If it's me, and maybe I've got past the initial scan and now I'm looking for more details to prepare for an interview, I'd like at least a rough idea of your level with any relevant skills you're claiming. That means, broadly speaking, how much experience in total and how recently you used that skill.

A list of buzzwords and a list of projects but no matching between them doesn't tell me which are your relatively strong skills. Unfortunately, I'm going to assume by default that none of them are particularly strong, simply because in my experience most people who list lots of skills on a CV/resume but don't highlight their particular strengths among those skills usually aren't very strong at anything.

If you do have relatively strong areas, particularly those that are relevant to specific job, then failing to highlight them means at best you're missing a chance to direct the interview in a way that is going to make you look good. At worst, you're going to get asked about your weaker skills and if you get caught out on the technical questions/programming test/whatever the interviewers are going to assume your other skills are all of that level.

If by 'real people' you mean recruiters, that's not my primary target audience, I have an utterly boring, scannable MS-Word document for them if needed.

I guess in that case my question is: who is your primary target audience for this document? If it's technical/management guys who are going to be conducting an interview once you're past the recruiters, I'd still say scannability is essential. It's totally unfair that people who are going to make decisions that could have a major effect on your life aren't necessarily going to read the whole document you've spent so much time and care preparing, but in the real world, that's often going to be the case, so you might as well play by the same rules as everyone else!