In Stephen's spec, when you mouse over a one-off, its left and right borders are changed so that they extend all the way from the top of the button to the bottom. http://people.mozilla.org/~shorlander/mockups-interactive/awesomebar-results/awesomeBar-results-tabOrdering.html

Unassigning myself from non-P1 search bugs for now so I have more time for Photon bugs.

#identity-box and #urlbar-display-box use this nice technique to show a border that doesn't extend all the way to the top and bottom: > #urlbar-display-box { > border-inline-end: 1px solid var(--urlbar-separator-color); > border-image: linear-gradient(transparent 15%, var(--urlbar-separator-color) 15%, var(--urlbar-separator-color) 85%, transparent 85%); > border-image-slice: 1; > } We should be able to replace the background image with this. The border-image and border-image-slice would only be applied on not(hover). See also bug 1373990. https://hg.mozilla.org/mozilla-central/annotate/a6a1f5c1d971dbee67ba6eec7ead7902351ddca2/browser/themes/shared/identity-block/identity-block.inc.css#l62