Cleanup admin nav and header styling

src/stylesheets/components/_adminHeader.scss

@@ -11,6 +11,7 @@
 		left: 13%;
 		color: $primary-colour;
 		font-size: 1.3em;
+		cursor: pointer;
 
 		@include respond-to('large') {
 			display: none;

src/stylesheets/components/_adminNav.scss

@@ -12,10 +12,6 @@
 	padding-top: 5rem;
 	z-index: 50;
 
-	a {
-		color: white;
-	}
-
 	&__profile {
 		display: flex;
 		flex-direction: column;

src/stylesheets/components/_adminNavItem.scss

@@ -5,6 +5,11 @@
 	padding: 2rem 0;
 	border-bottom: 1px solid white;
 	width: 70%;
+	color: white;
+
+	&.current {
+		background-color: $primary-colour-dark;
+	}
 
 	&:last-child {
 		border: none;
@@ -12,5 +17,6 @@
 
 	@include on-event() {
 		background-color: $primary-colour-dark;
+		text-decoration: none;
 	}
 }