control gradient degree in main section of betterland

[dr-JT]

This is a very minor feature and does not deserve too much time spent on but I think it would be nice.

Also, for posterdown_html an option to set a color and or color gradient for the entire background (title section and body included)

[ethanweed]

For anybody who, like me, has found this post because you also want to alter the color gradient on your poster (or for myself, when I have forgotten this a year from now), I ended up achieving this by using the following method:

1. Knit the poster
2. Open the resulting html file in a text editor
3. Find the line in the html that looks something like this: background-image: linear-gradient(#918E80 50%, #433F30);
4. Change the percentage to whatever you like
5. Save the html file with your changes
6. Create a pdf from your altered html file using the following code in R: pagedown::chrome_print(PATH, format = "pdf") where PATH is the path to your html file (requires that you have Chrome installed)

By the way, this method also allowed me to control some things like the color of the author names and affiliations, which do have YAML keys, but which don't seem to work (at least for me).