Thanks for the idea. Doesn’t quite work (has no effect). The following:
.site-header {
background-size: 100% 100%;
}
Get it closer, in the sense that the full height is shown, but only because the image is stretched (not original proportions).
Part of the problem seems to be that the page inherits height and min-height values in pixels from the css sheet. For example, using Inspect Element, looks like height is set to 192 px, and min-height is set to 120 px. But if you remove these, the header image completely disappears.
Little help?
