diff --git a/src/shared/ui/Button/index.ts b/src/shared/ui/Button/index.ts
new file mode 100644
index 0000000..ee20067
--- /dev/null
+++ b/src/shared/ui/Button/index.ts
@@ -0,0 +1,2 @@
+export { Button } from './ui/Button'
+export type { ButtonVariant, ButtonSize } from './ui/Button'
diff --git a/src/shared/ui/Button/ui/Button.test.tsx b/src/shared/ui/Button/ui/Button.test.tsx
new file mode 100644
index 0000000..48410b8
--- /dev/null
+++ b/src/shared/ui/Button/ui/Button.test.tsx
@@ -0,0 +1,67 @@
+import { describe, it, expect, vi } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { Button } from './Button'
+
+describe('Button', () => {
+  describe('rendering', () => {
+    it('renders children', () => {
+      render(<Button>Click me</Button>)
+      expect(screen.getByRole('button', { name: 'Click me' })).toBeInTheDocument()
+    })
+    it('renders as button element', () => {
+      render(<Button>Click</Button>)
+      expect(screen.getByRole('button')).toBeInTheDocument()
+    })
+  })
+  describe('variants', () => {
+    it('applies primary variant by default', () => {
+      render(<Button>Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('bg-burnt-oxide')
+    })
+    it('applies secondary variant', () => {
+      render(<Button variant="secondary">Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('bg-slate-indigo')
+    })
+    it('applies outline variant', () => {
+      render(<Button variant="outline">Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('bg-transparent')
+    })
+    it('applies ghost variant', () => {
+      render(<Button variant="ghost">Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('bg-ochre-clay')
+    })
+  })
+  describe('sizes', () => {
+    it('applies md size by default', () => {
+      render(<Button>Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('px-6', 'py-3')
+    })
+    it('applies sm size', () => {
+      render(<Button size="sm">Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('px-4', 'py-2')
+    })
+    it('applies lg size', () => {
+      render(<Button size="lg">Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('px-8', 'py-4')
+    })
+  })
+  describe('interactions', () => {
+    it('calls onClick when clicked', async () => {
+      const onClick = vi.fn()
+      render(<Button onClick={onClick}>Go</Button>)
+      await userEvent.click(screen.getByRole('button'))
+      expect(onClick).toHaveBeenCalledOnce()
+    })
+    it('is disabled when disabled prop is set', () => {
+      render(<Button disabled>Go</Button>)
+      expect(screen.getByRole('button')).toBeDisabled()
+    })
+  })
+  describe('className passthrough', () => {
+    it('merges custom className', () => {
+      render(<Button className="w-full">Go</Button>)
+      expect(screen.getByRole('button')).toHaveClass('w-full')
+    })
+  })
+})
diff --git a/src/shared/ui/Button/ui/Button.tsx b/src/shared/ui/Button/ui/Button.tsx
new file mode 100644
index 0000000..c1f256c
--- /dev/null
+++ b/src/shared/ui/Button/ui/Button.tsx
@@ -0,0 +1,48 @@
+import type { ButtonHTMLAttributes, ReactNode } from 'react'
+import { cn } from '$shared/lib'
+
+export type ButtonVariant = 'primary' | 'secondary' | 'outline' | 'ghost'
+export type ButtonSize = 'sm' | 'md' | 'lg'
+
+interface Props extends ButtonHTMLAttributes<HTMLButtonElement> {
+  /**
+   * Visual variant
+   * @default 'primary'
+   */
+  variant?: ButtonVariant
+  /**
+   * Size preset
+   * @default 'md'
+   */
+  size?: ButtonSize
+  /**
+   * Button content
+   */
+  children: ReactNode
+}
+
+const VARIANTS: Record<ButtonVariant, string> = {
+  primary:   'bg-burnt-oxide text-ochre-clay',
+  secondary: 'bg-slate-indigo text-ochre-clay',
+  outline:   'bg-transparent text-carbon-black border-carbon-black',
+  ghost:     'bg-ochre-clay text-carbon-black border-carbon-black',
+}
+
+const SIZES: Record<ButtonSize, string> = {
+  sm: 'px-4 py-2 text-sm',
+  md: 'px-6 py-3 text-base',
+  lg: 'px-8 py-4 text-lg',
+}
+
+const BASE = 'brutal-border brutal-shadow transition-all duration-200 hover:translate-x-[2px] hover:translate-y-[2px] hover:shadow-[6px_6px_0_var(--carbon-black)] active:translate-x-[4px] active:translate-y-[4px] active:shadow-[4px_4px_0_var(--carbon-black)] uppercase tracking-wider'
+
+/**
+ * Brutalist button with variants and sizes.
+ */
+export function Button({ variant = 'primary', size = 'md', className, children, ...props }: Props) {
+  return (
+    <button className={cn(BASE, VARIANTS[variant], SIZES[size], className)} {...props}>
+      {children}
+    </button>
+  )
+}