When editing a field in the review request page, the boundaries of the

edit box would raise up by a fraction of a pixel in Firefox, and could

raise by a full pixel in Chrome. This was most noticeable when zooming

into the page.
This problem was caused by the field label and the edit icon's vertical

alignment. The icon was aligned at the baseline, which would change when

showing or hiding the icon. This led to a small change in the height of

the label area, causing the editor to shift.
We now set an explicit vertical-align: top on the icon, helping ensure

a stable bounding rectangle and therefore height.
We also ensure that #review-request-main always has an integer height,

in order to avoid other subtle sub-pixel issues that could impact

layout and offset calculations.

Zoomed far into the browser and toggled the edit state of different

fields, making sure that the top-left boundaries remained fixed in

place.