North Star. A sharp four-point navigational star — long vertical and horizontal points, pinched short diagonals — carrying the "your trusted guide" positioning that anchors the human-signed clinical promise. A single 1px scan line crosses dead center as a quiet radiology cue (the reading-room monitor sweep); it stays subtle so the star reads cleanly at 16px favicon size and holds up monochrome, in cyan, or inverse. Astra (star) and Rad (ray) resolve into one guiding emission point.