If you’re using the old version of Epik then yes it is 1152px (version 1.3 is 1140px). Think of it like this, the width is only 1152px, so that means the header, content, footer and everything else (excluding the background) inside of the theme will not exceed 1152px. If you’re viewing from any browser that is wider than 1152px then of course you’ll see extra space from the background on the side. Also, if you resize the browser, the theme becomes smaller, but there will still be space on the sides (which is what you want) so the content and images aren’t all the way on the edge of the screen. This makes is much easier to read content and view images. If you want something to be full width, then you would have to remove the width from the css and create a large enough image that can be scaled.
Another example – I’m viewing an 1152px width theme on a 1400px wide computer screen, which means there will be extra space left over, and thats what the background is for.
That’s about the best way I can explain it.
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