Change the width of the header image

This is a bit tricky to modify, but you can try the following CSS:

@media all and (min-width: 1500px) {

	.header-promo {
		width: calc(100% + 100px);
		left: -50px;
	}
}

The way it works now, the header image is going to expand to the full width of the screen up until it’s 1400px wide. The code above will modify it so it increases up to 1500px wide when there is enough space.