This CSS rule collides with an automatically added class “tag-list” on the body element on topics tagged with “list”.
.tag-list {
margin-top: 2em;
padding-bottom: 1em;
border-bottom: 1px solid $primary-low;
}
This adds a 2em margin to the top of the header which looks pretty silly.
This reproduces on try.discourse.org.
This is the SCSS file responsible: