_popover.scss

/**
 * Mousemove padding styles are used to add invisible elements to the popover
 * to allow mouse movement from the popover trigger to the popover itself
 * without triggering a mouseleave event.
 */
.popover-mousemove-padding-bottom {
    bottom: -15px;
    height: 20px;
    position: absolute;
    right: 0;
    width: 100%;
}
.popover-mousemove-padding-right {
    height: 100%;
    position: absolute;
    right: -20;
    top: 0;
    width: 40px;
}

/**
 * An invisible element is added to the top of the popover to ensure the mouse
 * stays over the popover when the popover's height is shrunk, which would then
 * normally leave the mouse outside of the popover itself and cause a mouseleave
 * event.
 */
.popover-mouse-padding-top {
    height: 30px;
    position: absolute;
    right: 0;
    top: -25px;
    width: 100%;
}