OpenDroneMap-WebODM/coreplugins/measure/public/app.scss

.leaflet-control-measure,
.leaflet-measure-resultpopup{
    h3{
        font-size: 120%;
    } 
}

.leaflet-control-measure-interaction{
    a{
        width: auto !important;
        height: auto !important;
        line-height: auto !important;
        display: initial !important;

        &:hover{
            background-color: inherit !important;
        }
    }
}