Site title hovering over header image?

I want to keep the site title and tag line but not have it appear over my header image. \.header-image .site-description,
.header-image .site-title {
display: block;
}
\
seems to be working fine on the home page but if you navigate to any other page or posts, the site title superimposes itself over my header image. What can I do to change this?

My site can be found at https://vivianlindsay.com/.
If you view just the homepage, it looks exactly like I want it to.

For an example of what I’m talking about, here is a post.