style the nature-affected pokémon stats

style/shiny/pkmn.css

@@ -49,6 +49,22 @@
 }
 
 
+.pkmn-nature-down {
+  color: hsl(200deg, 80%, 80%);
+}
+
+.pkmn-nature-up {
+  color: hsl(340deg, 100%, 87%);
+}
+
+th:is(.pkmn-nature-down,.pkmn-nature-up)::after {
+  vertical-align: super;
+  font-weight: 500;
+}
+
+th.pkmn-nature-down::after { content: '−'; }
+th.pkmn-nature-up::after   { content: '+'; }
+
 
 .bug {
   --type-col: #83c300;