.leaflet-measure-path-measurement {
 position: absolute;
 font-size: 10px;
 color: black;
 text-shadow: -1px 0 0 white, -1px -1px 0 white, 0 -1px 0 white, 1px -1px 0 white, 1px 0 0 white, 1px 1px 0 white, 0 1px 0 white, -1px 1px 0 white;
 white-space: nowrap;
 transform-origin: 0;
}

.leaflet-measure-path-measurement > div {
 position: relative;
 margin-top: -25%;
 left: -50%;
}