I want to have a header with a linear gradient background with some text on the left and an image on the right. All of this works OK if applied on each topic individually.
At some point I decided to use masterpages to store the header, since it should show up on each topic/page.
It turned out that the gradient background disappears on Microsoft HTML Help (.chm) output if it's sourced from the masterpage. Responsive HTML5 output doesn't have that problem. Also when I replace gradient with solid color the background is again visible on .chm.
Is there any trick that could fix this? Has anyone had a similar problem?
CHM uses something like Internet Explorer 7, I believe, so any CSS needs to be supported by that browser. (chm hasn't been updated by MS since about 2006...)
You can check broswer support here: https://caniuse.com/
For linear-gradient, the site says that IE7 has a proprietary filter for gradients, which you could try. No guarantees though.
indeed it worked when I added this on the masterpage:
But that also let me realize that playing with ancient technologies like .chm is asking for trouble;)