New: Native Theme Engine

Co-Authored-By: Zak Saunders <1936903+thezak48@users.noreply.github.com>

frontend/src/Components/Page/Header/MovieSearchInput.css

@@ -12,22 +12,22 @@
 .ripple {
   composes: ripple from '~Components/Loading/LoadingIndicator.css';
 
-  border: 1px solid $toolbarColor;
+  border: 1px solid var(--toolbarColor);
 }
 
 .input {
   margin-left: 8px;
   width: 200px;
   border: none;
-  border-bottom: solid 1px $white;
+  border-bottom: solid 1px var(--white);
   border-radius: 0;
   background-color: transparent;
   box-shadow: none;
-  color: $white;
+  color: var(--white);
   transition: border 0.3s ease-out;
 
   &::placeholder {
-    color: $white;
+    color: var(--white);
     transition: color 0.3s ease-out;
   }
 
@@ -60,13 +60,13 @@
     overflow-y: auto;
     min-width: 100%;
     max-height: 230px;
-    border: 1px solid $themeDarkColor;
+    border: 1px solid var(--themeDarkColor);
     border-radius: 4px;
     border-top-left-radius: 0;
     border-top-right-radius: 0;
-    background-color: $themeDarkColor;
-    box-shadow: inset 0 1px 1px $inputBoxShadowColor;
-    color: $menuItemColor;
+    background-color: var(--themeDarkColor);
+    box-shadow: inset 0 1px 1px var(--inputBoxShadowColor);
+    color: var(--menuItemColor);
   }
 }
 
@@ -82,12 +82,12 @@
 }
 
 .highlighted {
-  background-color: $themeLightColor;
+  background-color: var(--themeLightColor);
 }
 
 .sectionTitle {
   padding: 5px 8px;
-  color: $disabledColor;
+  color: var(--disabledColor);
 }
 
 .addNewMovieSuggestion {