diff --git a/src/__tests__/config.test.ts b/src/__tests__/config.test.ts
new file mode 100644
index 0000000..d131617
--- /dev/null
+++ b/src/__tests__/config.test.ts
@@ -0,0 +1,87 @@
+// Tests for src/config.ts
+// Test 1: CONFIG.grid.rows equals 10
+// Test 2: CONFIG.grid.cols equals 16
+// Test 3: CONFIG.emojis has exactly 16 emojis
+// Test 4: CONFIG.tile.size and gap are positive numbers
+
+import { describe, it, expect } from 'vitest';
+import { CONFIG } from '../config';
+
+describe('CONFIG', () => {
+  describe('grid', () => {
+    it('should have rows equal to 10', () => {
+      expect(CONFIG.grid.rows).toBe(10);
+    });
+
+    it('should have cols equal to 16', () => {
+      expect(CONFIG.grid.cols).toBe(16);
+    });
+
+    it('should have totalTiles equal to rows * cols', () => {
+      expect(CONFIG.grid.totalTiles).toBe(CONFIG.grid.rows * CONFIG.grid.cols);
+      expect(CONFIG.grid.totalTiles).toBe(160);
+    });
+
+    it('should have pairsPerType equal to 10', () => {
+      expect(CONFIG.grid.pairsPerType).toBe(10);
+    });
+  });
+
+  describe('tile', () => {
+    it('should have positive size', () => {
+      expect(CONFIG.tile.size).toBeGreaterThan(0);
+    });
+
+    it('should have positive gap', () => {
+      expect(CONFIG.tile.gap).toBeGreaterThan(0);
+    });
+
+    it('should have positive cornerRadius', () => {
+      expect(CONFIG.tile.cornerRadius).toBeGreaterThanOrEqual(0);
+    });
+  });
+
+  describe('emojis', () => {
+    it('should have exactly 16 emojis', () => {
+      expect(CONFIG.emojis).toHaveLength(16);
+    });
+
+    it('should contain the correct emoji set', () => {
+      const expectedEmojis = [
+        '🌟', '⭐', '💫', '✨', '🌙', '☀️', '🔥', '💧',
+        '🌿', '⚡', '🧊', '🪨', '🌸', '🍃', '🌊', '🍄'
+      ];
+      expect(CONFIG.emojis).toEqual(expectedEmojis);
+    });
+  });
+
+  describe('colors', () => {
+    it('should have valid hex background color', () => {
+      expect(CONFIG.colors.background).toMatch(/^#[0-9a-fA-F]{6}$/);
+    });
+
+    it('should have valid hex tile color', () => {
+      expect(CONFIG.colors.tile).toMatch(/^#[0-9a-fA-F]{6}$/);
+    });
+
+    it('should have valid hex tileHover color', () => {
+      expect(CONFIG.colors.tileHover).toMatch(/^#[0-9a-fA-F]{6}$/);
+    });
+
+    it('should have valid hex selection color', () => {
+      expect(CONFIG.colors.selection).toMatch(/^#[0-9a-fA-F]{6}$/);
+    });
+
+    it('should have valid hex text color', () => {
+      expect(CONFIG.colors.text).toMatch(/^#[0-9a-fA-F]{6}$/);
+    });
+
+    it('should have the correct color values', () => {
+      expect(CONFIG.colors.background).toBe('#1a1a2e');
+      expect(CONFIG.colors.tile).toBe('#16213e');
+      expect(CONFIG.colors.tileHover).toBe('#0f3460');
+      expect(CONFIG.colors.selection).toBe('#e94560');
+      expect(CONFIG.colors.text).toBe('#eaeaea');
+    });
+  });
+});
diff --git a/src/config.ts b/src/config.ts
new file mode 100644
index 0000000..a9b15b7
--- /dev/null
+++ b/src/config.ts
@@ -0,0 +1,27 @@
+// src/config.ts - Game configuration constants
+// All game constants in one place, easily tunable
+
+export const CONFIG = {
+  grid: {
+    rows: 10,
+    cols: 16,
+    totalTiles: 160,
+    pairsPerType: 10,
+  },
+  tile: {
+    size: 48,
+    gap: 4,
+    cornerRadius: 8,
+  },
+  emojis: [
+    '🌟', '⭐', '💫', '✨', '🌙', '☀️', '🔥', '💧',
+    '🌿', '⚡', '🧊', '🪨', '🌸', '🍃', '🌊', '🍄'
+  ],
+  colors: {
+    background: '#1a1a2e',
+    tile: '#16213e',
+    tileHover: '#0f3460',
+    selection: '#e94560',
+    text: '#eaeaea',
+  },
+} as const;