Steps to Reproduce

double click a cell to enter inline editing mode
hover the bottom right corner of the cell

Current Result

the inline editbox starts flickering in size
(the inline editbox is slightly misaligned)

Expected Result

no flickering
correctly aligned inline edit box

Root Cause

side effect of: https://tracker.zkoss.org/browse/ZK-4153
it adds a 'z-InlineEditor-hover' class, triggering a change in the box-sizing property

Workaround

adding this css style globally fixes the misalignment and flickering

.zsedit-real {
    box-sizing: border-box;
    margin-top: 2px;
    margin-left: 1px;
}