diff --git a/components/ui/PrimaryButton.test.tsx b/components/ui/PrimaryButton.test.tsx
new file mode 100644
index 00000000..dc0ff464
--- /dev/null
+++ b/components/ui/PrimaryButton.test.tsx
@@ -0,0 +1,175 @@
+import { describe, it, expect } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import PrimaryButton from './PrimaryButton'
+
+describe('PrimaryButton', () => {
+  // ──────────────────────────────────────────────────────────────────────────
+  // Rendering
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('renders with children', () => {
+    render(<PrimaryButton>Submit</PrimaryButton>)
+    expect(screen.getByRole('button', { name: 'Submit' })).toBeInTheDocument()
+  })
+
+  it('renders with complex children', () => {
+    render(
+      <PrimaryButton>
+        <span data-testid="icon" />
+        Pay Now
+      </PrimaryButton>,
+    )
+    expect(screen.getByRole('button')).toBeInTheDocument()
+    expect(screen.getByTestId('icon')).toBeInTheDocument()
+    expect(screen.getByText('Pay Now')).toBeInTheDocument()
+  })
+
+  // ──────────────────────────────────────────────────────────────────────────
+  // Default styling
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('applies base visual classes', () => {
+    render(<PrimaryButton>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    // Base layout classes
+    expect(button.className).toContain('inline-flex')
+    expect(button.className).toContain('items-center')
+    expect(button.className).toContain('justify-center')
+    // Brand colour
+    expect(button.className).toContain('bg-brand.red')
+    expect(button.className).toContain('text-white')
+    // Sizing
+    expect(button.className).toContain('px-6')
+    expect(button.className).toContain('py-3')
+    expect(button.className).toContain('rounded-lg')
+    expect(button.className).toContain('font-semibold')
+    // Transition
+    expect(button.className).toContain('transition-colors')
+    expect(button.className).toContain('duration-150')
+  })
+
+  it('applies hover classes', () => {
+    render(<PrimaryButton>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button.className).toContain('hover:bg-brand.redHover')
+  })
+
+  it('applies focus classes', () => {
+    render(<PrimaryButton>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button.className).toContain('focus:outline-none')
+    expect(button.className).toContain('focus:ring-2')
+    expect(button.className).toContain('focus:ring-brand.red')
+    expect(button.className).toContain('focus:ring-offset-2')
+  })
+
+  // ──────────────────────────────────────────────────────────────────────────
+  // Disabled state
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('renders disabled when disabled prop is true', () => {
+    render(<PrimaryButton disabled>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button).toBeDisabled()
+  })
+
+  it('sets aria-disabled when disabled', () => {
+    render(<PrimaryButton disabled>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button).toHaveAttribute('aria-disabled', 'true')
+  })
+
+  it('does not set aria-disabled when enabled', () => {
+    render(<PrimaryButton>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button).not.toHaveAttribute('aria-disabled')
+  })
+
+  it('applies disabled visual classes', () => {
+    render(<PrimaryButton disabled>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button.className).toContain('disabled:opacity-50')
+    expect(button.className).toContain('disabled:cursor-not-allowed')
+    expect(button.className).toContain('disabled:hover:bg-brand.red')
+  })
+
+  it('does not trigger onClick when disabled', async () => {
+    const user = userEvent.setup()
+    let clicked = false
+    render(
+      <PrimaryButton disabled onClick={() => { clicked = true }}>
+        Send
+      </PrimaryButton>,
+    )
+    await user.click(screen.getByRole('button'))
+    expect(clicked).toBe(false)
+  })
+
+  // ──────────────────────────────────────────────────────────────────────────
+  // Custom className merging
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('merges custom className with default classes', () => {
+    render(<PrimaryButton className="extra-class">Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+    expect(button.className).toContain('extra-class')
+    // Default classes should still be present
+    expect(button.className).toContain('bg-brand.red')
+    expect(button.className).toContain('inline-flex')
+  })
+
+  // ──────────────────────────────────────────────────────────────────────────
+  // forwardRef support
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('forwards ref to the button element', () => {
+    const ref = { current: null as HTMLButtonElement | null }
+    render(<PrimaryButton ref={ref}>Send</PrimaryButton>)
+    expect(ref.current).toBeInstanceOf(HTMLButtonElement)
+    expect(ref.current?.tagName).toBe('BUTTON')
+  })
+
+  it('has correct displayName', () => {
+    expect(PrimaryButton.displayName).toBe('PrimaryButton')
+  })
+
+  // ──────────────────────────────────────────────────────────────────────────
+  // Additional HTML button attributes
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('supports type attribute', () => {
+    render(<PrimaryButton type="submit">Submit</PrimaryButton>)
+    expect(screen.getByRole('button')).toHaveAttribute('type', 'submit')
+  })
+
+  it('supports aria-label', () => {
+    render(<PrimaryButton aria-label="Close dialog">X</PrimaryButton>)
+    expect(screen.getByRole('button', { name: 'Close dialog' })).toBeInTheDocument()
+  })
+
+  it('supports data-* attributes', () => {
+    render(<PrimaryButton data-testid="submit-btn">Send</PrimaryButton>)
+    expect(screen.getByTestId('submit-btn')).toBeInTheDocument()
+  })
+
+  // ──────────────────────────────────────────────────────────────────────────
+  // Interaction parity: hover then focus
+  // ──────────────────────────────────────────────────────────────────────────
+
+  it('maintains hover class when focused', async () => {
+    const user = userEvent.setup()
+    render(<PrimaryButton>Send</PrimaryButton>)
+    const button = screen.getByRole('button')
+
+    await user.hover(button)
+    // Hover classes are present
+    expect(button.className).toContain('hover:bg-brand.redHover')
+
+    // Focus does not remove hover
+    button.focus()
+    expect(button.className).toContain('hover:bg-brand.redHover')
+    // Focus classes are also present
+    expect(button.className).toContain('focus:ring-2')
+  })
+})
\ No newline at end of file
diff --git a/lib/utils.ts b/lib/utils.ts
index 365058ce..607cb86e 100644
--- a/lib/utils.ts
+++ b/lib/utils.ts
@@ -1,6 +1 @@
-import { type ClassValue, clsx } from "clsx";
-import { twMerge } from "tailwind-merge";
-
-export function cn(...inputs: ClassValue[]) {
-  return twMerge(clsx(inputs));
-}
+export { cn } from "./utils/cn";
diff --git a/lib/utils/index.ts b/lib/utils/index.ts
index 37295e1c..c25627d5 100644
--- a/lib/utils/index.ts
+++ b/lib/utils/index.ts
@@ -1,6 +1 @@
-import { clsx } from "clsx";
-import { twMerge } from "tailwind-merge";
-
-export function cn(...inputs: Parameters<typeof clsx>) {
-  return twMerge(clsx(inputs));
-}
+export { cn } from "./cn";