I generally like pure css shapes, but I thought SVG might make your life easier in this case so I started fiddling around with your fiddle. I'm not completely satisfied with the results but it gives some advantage like dynamic size.
Fiddle with comments: http://jsfiddle.net/bo5k36pa/8/
If you want to use this solution I highly recommend to encode your inline svgs in base64 to avoid compability and encoding problems. See this answer for details.
Explanation
The idea was to use an inline svg as background image, so it will stretch to containers of any size.
background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 4 2" preserveAspectRatio="none"><path style="fill: rgb(2, 145, 178);" d="M 0.5 0 L 3.5 0 L 4 2 L 0 2 Z" /></svg>');
background-size: 100%;
The path that makes up the trapez could be modified, if different angles or shapes are required, it could even be generated dynamically using javascript. But the real bummer here is, we can't style inline svg background images. Meaning for example to change just the fill color we have to define the entire svg markup again.
Possible solutions to avoid multiple inline svgs
Use <use>
. You can define <symbols>
in an external svg file and reference them in an inline <svg>
via their id
attributes. And we can still style those symbols using CSS. However, it would require a fair amount of extra markup in every container. Something like this:
<svg viewBox="0 0 4 2" role="img" title="Trapez"><use xlink:href="path/to/images/shapes.svg#trapez"></use></svg>
Use CSS filters to change appearance. Example fiddle / Browser Support
Go back to CSS Shapes. I'd recommend to take advantage of :before and :after pseudo elements to keep such fancy appendages a bit separate from your content box.