While the new rows are being faded in, they each have an opacity not
equal to 1. Setting the opacity on something creates a new stacking
context, and because the rows are below the legend in the DOM, this made
them appear on top of the legend.
Fix this by setting a z-index on the legend so it stays on top.
Bug: T186841
Change-Id: I2eee201d1e0aed94974a85d6d46b86fd4a4db796
.mw-changeslist-legend {
background-color: @background-color-base;
position: relative; // We want to keep the legend accessible when results are overlaid
+ z-index: 1; // Keep opacity-animated highlights from appearing on top of the legend
border: 1px solid @colorGray12;
}