The mark was 22px wide inside a filled --primary tile, which read as a dark
badge with something small and indistinct in it — at that size neither the
silhouette nor the eye resolved.

It now sits directly on the sidebar surface and inverts with the theme:
near-black on the light background, near-white on the dark one. Losing the
tile's padding lets it grow to 40px expanded and 36px collapsed, roughly
double, so the chevrons separate and the eye is a dot rather than a smudge.
The filled tile stays the favicon's job, where an icon has to hold its own
against browser chrome it does not control.

With no tile behind it the eye contrasts with the page, not with --primary,
so --brand alone covers it and --brand-on-primary is gone.

Verified in both themes: stroke resolves to #18181b on light and #f4f4f5 on
dark, the eye to #0a4ecf and #5a8dff, and the mark renders 40x20.16 in the
expanded header.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

At 40px the mark read as a lump. The cause was proportion, not resolution:
stroke-width 13 on a 125-wide drawing left the counters nearly closed, and
the body notch was a 19-unit segment carrying a 13-unit stroke — 67% of its
own length, so it rendered as a blob welding the three shapes into one mass.

Stroke drops to 10 and the chevron apexes move inward (46.5/78.5 → 42/83),
widening each apex from 64° to 71° and stretching the body notch to ~25
units. The three shapes now separate and the eye reads as a dot rather than
part of the mass. The tight viewBox is unchanged, so every transform in the
favicon, app icons and lockups stays valid without recomputation.

Header size goes 40px → 50px. Every stroke in the mark is diagonal, so its
edges antialias at any size — that softness is inherent to the geometry, not
a rasterisation bug, and the only real remedy is more pixels. At 50px the
10-unit stroke also lands on exactly 4 device-independent pixels.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

In the collapsed rail the mark was 36x18 against 18x18 nav icons: equal in
height but twice as wide, so it carried far more visual mass than the row it
sits above and read as a banner rather than the first item in the rail.

It drops to 28x14.1. Bounding area now lands near the icons' (395 vs 324)
instead of double it, and the rail reads as one column. The expanded header
is untouched at 50px, where the mark has two lines of type to balance and
the extra presence is wanted.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

The header mark goes 50px → 40px (20.2px tall). 50px was chosen to buy
crispness, but the mark's edges are diagonal and antialias at any size, so
the extra width bought presence rather than sharpness — and outweighed the
two lines of type it sits beside. 40px balances that block.

The favicon drops the brand-blue tile for ink on white. A tab strip is a
dense row of other people's icons and a saturated blue tile competes there;
ink on white reads as the mark rather than as a colour, while the tile still
keeps the mark legible against dark browser chrome. The eye stays brand blue
— it is the accent everywhere else in the set, and dropping it would make
the favicon the only monochrome member.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

The tab icon was the master mark scaled down, which is the wrong operation
for 16px. It filled 64% of the tile and its stroke landed on 0.84px — under
one pixel, so it rendered as grey haze next to tab neighbours that are bold
shapes filling their whole box, and the white tile gave it nothing to sit
against on an active (white) tab.

The favicon now has its own optical size: same skeleton, stroke 10 → 13 and
fill 64% → 91% of the tile, which puts the line on ~1.47px and the eye on
~1.9px at tab scale. Stroke stays under half the body notch's length, so the
three shapes still separate rather than welding into a lump.

This one file deliberately diverges from the master geometry. Scaling a line
drawing down past a certain point stops preserving it — below roughly 24px
the stroke has to be redrawn, not resized.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

The white tile only ever looked right on the active tab. Everywhere else the
tab strip is tinted, so the icon read as a white square with something inside
it rather than as a mark.

Dropping the tile also buys room: with nothing to sit inside, the mark fills
94% of the box instead of 64% and the stroke goes 13 → 14, putting the line
on ~1.6px at tab scale, up from 1.47px.

With no tile the ink has to carry itself against whatever is behind it, so
the file switches on prefers-color-scheme — #111111 on light browser chrome,
#ffffff on dark — instead of assuming a light one and disappearing.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>