Mary, great tutorial here. Thanks for the start. I have added your code and the logo does go away. I guess the next steps would be to find the other elements in the header and force them to not display for the attempt page.
How did you find a.logo? I was able to perform a recursive grep on all my files in the essential theme and it looks like this logo is referenced in the following locations:
theme/essential/style/essential.css
theme/essential/style/settings.css
So, I took a look a the references in the header area and adjacent to a.logo in the essential.css file, attempted to hide elements with the following code:
#page-mod-quiz-attempt h2.main {display: none;}
#page-mod-quiz-attempt page-header {display: none;}
#page-mod-quiz-attempt userpicture {display: none;}
No effect, unfortunately. I guess if I can get your thought process for a.logo then perhaps I can move forward. I'd like the entire header band to disappear, for my quiz to look like this: