Fix the Nethack page at small screen sizes

assets/scripts/nethack/dungeon.js

@@ -723,7 +723,8 @@ new p5(p => {
 
     const gridBounds = Rect.fromCoordinates(
       0, 0,
-      Math.ceil(canvasWidth / CELL_WIDTH) - 1, Math.ceil(canvasHeight / CELL_HEIGHT) - 1
+      Math.max(80, Math.ceil(canvasWidth / CELL_WIDTH) - 1),
+      Math.max(24, Math.ceil(canvasHeight / CELL_HEIGHT) - 1)
     );
 
     console.log(`Generating grid with size ${gridBounds.size.width} x ${gridBounds.size.height}`);

assets/styles/nethack.css

@@ -32,7 +32,7 @@
 }
 
 main {
-  background: black;
+  background: rgba(var(--black), 0.6);
 }
 
 #dungeon-background {