Dcat-Admin/resources/assets/dcat/sass/components/_popover.scss

.popover {
  font-family: $font-family-sans-serif;
  border: 0;
  box-shadow: $shadow-100;
  max-width: 320px;
}

.bs-popover-right > .arrow::before, .bs-popover-auto[x-placement^=right] > .arrow::before {
  border-right-color: #eee;
}