Add high contrast themes.

source/scss/style.scss

@@ -3,6 +3,7 @@
 
 // Theme definitions
 @use 'themes/dracula';
+@use 'themes/high-contrast';
 @use 'themes/love';
 @use 'themes/monokai';
 @use 'themes/solarized';

source/scss/themes/_high-contrast.scss

@@ -0,0 +1,15 @@
+.high-contrast-black {
+  --border-radius: 8px;
+  --foreground-1: #fff;
+  --foreground-2: #ddd;
+  --background-1: #000;
+  --background-2: #222;
+}
+
+.high-contrast-white {
+  --border-radius: 8px;
+  --foreground-1: #000;
+  --foreground-2: #222;
+  --background-1: #fff;
+  --background-2: #ddd;
+}

source/ts/utilities/themes.ts

@@ -32,6 +32,14 @@ export const themes: Theme[] = [
     cssClass: 'monokai',
     name: 'Monokai',
   },
+  {
+    cssClass: 'high-contrast-black',
+    name: 'High Contrast Black',
+  },
+  {
+    cssClass: 'high-contrast-white',
+    name: 'High Contrast White',
+  },
 ].sort((a, b) => a.name.localeCompare(b.name));
 
 export const themeContext = createContext<Theme>(defaultTheme);