theseus.x, sirius.x and hephaestus.x had a 1px border-bottom under the
sticky/fixed topnav that read as a visible separator between the
navigation and the page. The topnav's own translucent-blur backdrop is
enough of a distinction already — the line is redundant and, on the
theseus.x sidebar layout, made the top of the sidebar look like it was
overhanging the header.
theseus.x tabs also had a "Sirius .X" gap because the topnav <a> is a
flex container and the icon + "Sirius" text + ".X" span were three
flex items with a 6px gap between each. Wrapping the label in one
<span> collapses the gap to a single space between icon and label.
Sidebar border-right and mobile bottom-bar border-top also dropped —
the panel tint carries the boundary; a hard line was too heavy.
74c4c50c4e
