Annoying dashed border ( which isn’t even a border, is an outline ) appears around the blocks when the “gear” edit link is hovered, but more annoying is when you want to hide some text by the old “text-indent: -9999em” method; then the annoying border stretches all the way to the left ( normally, cause of the ‘-9999em’ ).

A quick way to remove it:

.block.contextual-links-region-active {
	outline: 0;
}