diff --git a/app/generator/components/sections/CommitPulseSection.responsive-breakpoints.test.tsx b/app/generator/components/sections/CommitPulseSection.responsive-breakpoints.test.tsx
new file mode 100644
index 000000000..ccded80a9
--- /dev/null
+++ b/app/generator/components/sections/CommitPulseSection.responsive-breakpoints.test.tsx
@@ -0,0 +1,153 @@
+import React from 'react';
+import { describe, expect, it, vi, beforeEach, afterEach } from 'vitest';
+import { render, screen, waitFor } from '@testing-library/react';
+import '@testing-library/jest-dom';
+import { CommitPulseSection } from './CommitPulseSection';
+
+// Mock sub-components cleanly to avoid nested rendering dependencies
+vi.mock('../SectionCard', () => ({
+  SectionCard: ({ title, children }: { title: string; children: React.ReactNode }) => (
+    <div data-testid="section-card">
+      <h2>{title}</h2>
+      {children}
+    </div>
+  ),
+  FieldLabel: ({ htmlFor, children }: { htmlFor: string; children: React.ReactNode }) => (
+    <label htmlFor={htmlFor}>{children}</label>
+  ),
+}));
+
+// Mock debouncing hook to bypass setTimeout lags instantly during runtime evaluations
+vi.mock('@/hooks/useDebounce', () => ({
+  useDebounce: (value: string) => value,
+}));
+
+// Mock local validation helper methods
+vi.mock('@/lib/validations', () => ({
+  validateGitHubUsername: (username: string) =>
+    username.length > 0 && !username.includes('invalid'),
+}));
+
+describe('CommitPulseSection - Responsive Multi-device Columns & Mobile Viewport Layouts', () => {
+  const mockOnGithubUsernameChange = vi.fn();
+  const mockOnShowCommitPulseChange = vi.fn();
+  const mockOnCommitPulseAccentChange = vi.fn();
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.spyOn(global, 'fetch').mockResolvedValue({
+      ok: true,
+      json: async () => ({
+        exists: true,
+        login: 'octocat',
+        name: 'The Octocat',
+        avatar_url: 'https://example.com/avatar.png',
+        public_repos: 8,
+        stats: { currentStreak: 5, longestStreak: 12, totalContributions: 42 },
+      }),
+    } as Response);
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  // Test 1: Full fluid layout scaling compliance
+  it('implements global full-width fluid configurations on core input elements to prevent clipping', () => {
+    render(
+      <CommitPulseSection
+        githubUsername=""
+        showCommitPulse={true}
+        commitPulseAccent=""
+        onGithubUsernameChange={mockOnGithubUsernameChange}
+        onShowCommitPulseChange={mockOnShowCommitPulseChange}
+        onCommitPulseAccentChange={mockOnCommitPulseAccentChange}
+      />
+    );
+
+    const usernameInput = screen.getByLabelText(/GitHub Username/i);
+    expect(usernameInput).toHaveClass('w-full');
+  });
+
+  // Test 2: Multi-column grid distribution profiles
+  it('implements responsive multi-column distributions inside the dashboard metrics section', async () => {
+    const { container } = render(
+      <CommitPulseSection
+        githubUsername="octocat"
+        showCommitPulse={true}
+        commitPulseAccent=""
+        onGithubUsernameChange={mockOnGithubUsernameChange}
+        onShowCommitPulseChange={mockOnShowCommitPulseChange}
+        onCommitPulseAccentChange={mockOnCommitPulseAccentChange}
+      />
+    );
+    await waitFor(() => {
+      expect(screen.getByText('The Octocat')).toBeInTheDocument();
+    });
+
+    const statsGrid = container.querySelector('[class*="grid-cols-3"]');
+    expect(statsGrid).not.toBeNull();
+    expect(statsGrid).toHaveClass('grid');
+
+    expect(screen.getByText('Current Streak')).toBeInTheDocument();
+    expect(screen.getByText('Longest Streak')).toBeInTheDocument();
+    expect(screen.getByText('Contributions')).toBeInTheDocument();
+  });
+
+  // Test 3: Fluid image rendering width metrics
+  it('enforces maximum boundary scaling restrictions on visual asset elements', async () => {
+    render(
+      <CommitPulseSection
+        githubUsername="octocat"
+        showCommitPulse={true}
+        commitPulseAccent=""
+        onGithubUsernameChange={mockOnGithubUsernameChange}
+        onShowCommitPulseChange={mockOnShowCommitPulseChange}
+        onCommitPulseAccentChange={mockOnCommitPulseAccentChange}
+      />
+    );
+
+    const badgeImage = await screen.findByRole('img', { name: /CommitPulse badge for octocat/i });
+    expect(badgeImage).toBeInTheDocument();
+    expect(badgeImage).toHaveClass('w-full');
+    expect(badgeImage).toHaveClass('max-w-[480px]');
+  });
+
+  // Test 4: Element spacing structural configurations
+  it('implements structural gap spacing within form rows to prevent element collision layouts', () => {
+    render(
+      <CommitPulseSection
+        githubUsername="" // Empty string bypasses the background async loop cleanly
+        showCommitPulse={true}
+        commitPulseAccent=""
+        onGithubUsernameChange={mockOnGithubUsernameChange}
+        onShowCommitPulseChange={mockOnShowCommitPulseChange}
+        onCommitPulseAccentChange={mockOnCommitPulseAccentChange}
+      />
+    );
+
+    const inputWrapper = screen.getByLabelText(/GitHub Username/i).closest('.relative');
+    expect(inputWrapper).not.toBeNull();
+
+    const formContainer = inputWrapper?.parentElement?.parentElement;
+    expect(formContainer).toHaveClass('flex-col');
+    expect(formContainer).toHaveClass('gap-4');
+  });
+
+  // Test 5: Accessible Interactive Controls
+  it('maintains clear landmark interactivity rules on layout status control targets', () => {
+    render(
+      <CommitPulseSection
+        githubUsername=""
+        showCommitPulse={false}
+        commitPulseAccent=""
+        onGithubUsernameChange={mockOnGithubUsernameChange}
+        onShowCommitPulseChange={mockOnShowCommitPulseChange}
+        onCommitPulseAccentChange={mockOnCommitPulseAccentChange}
+      />
+    );
+
+    const toggleSwitch = screen.getByRole('switch', { name: /Toggle CommitPulse badge/i });
+    expect(toggleSwitch).toBeInTheDocument();
+  });
+});