37ffeac5f0
Switch #spectrum-bookmark-axis from position:relative (creates gap) to position:absolute at top:var(--spectrum-plot-height) with transform:translateY(-50%), so it floats centred on the boundary without affecting layout. z-index:6 keeps it above the BW/freq selector signal overlay (z-index 4). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Signed-off-by: Stan Grams <sjg@haxx.space>