Hi Darren,
Sorry for not explaining it. Ok, the purpose of min-height: 100vh there is to make the first section occupy the entire height of the screen (above-fold), regardless of how big the screen is (desktop, laptop, mobile).
Using vw and vh
But we need to offset the height of the header from that 100vh so we did use the calc() CSS function to do that. So the 212px there is the height of your entire header (logobar & menu bar). That is why we come up with this:
$el.x-section {
min-height: calc(100vh - 212px);
}
What that does is to make sure the header and the first section occupy the above the fold regardless if your slider is there or not.
But that min-height is only initial though, because eventually when slider loads the height of the first section will respond to the height of the slider.
Or if your slider has a fixed height, you can actually use that value to be the min-height of the section.
Hope that shed some lights,
Cheers!