If you only need these rules in one area, you're better served targeting the specific component.
/* Chrome, Safari, Edge, Opera */
#myTargetDomId input::-webkit-outer-spin-button,
#myTargetDomId input::-webkit-inner-spin-button {
-webkit-appearance: none;
margin: 0;
}
/* Firefox */
#myTargetDomId input[type=number] {
-moz-appearance: textfield;
}
Couple this with use of the meta.domId
property to target an individual component.