diff --git a/plans/button.md b/plans/button.md
new file mode 100644
index 0000000..d140a44
--- /dev/null
+++ b/plans/button.md
@@ -0,0 +1,68 @@
+# Button Component Plan
+
+## Source
+Example pasted into Figma Examples page (node 10:20). Original has 5 properties × many values = 360+ variants. We're building the light-mode subset.
+
+## Props (React)
+
+```tsx
+interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: 'primary' | 'secondary' | 'tertiary'
+  color?: 'navy' | 'red' | 'light' | 'surface'
+  size?: 'default' | 'comfortable' | 'compact'
+  leftIcon?: React.ReactNode
+  rightIcon?: React.ReactNode
+}
+```
+
+- `children` is the label text
+- States (hover, active, focus, disabled) handled via CSS pseudo-classes
+- Uses `forwardRef` to wrap `<button>`
+
+## Colour Scheme Mapping
+
+| Prop value | Example name | Primary bg | Primary text | Secondary border | Our tokens |
+|---|---|---|---|---|---|
+| `navy` | Navy | #002664 | white | #002664 | `blue-01`, `white` |
+| `red` | Red | #D7153A | white | #D7153A | `red-02`, `white` |
+| `light` | On Primary (Teal) | #CBEDFD | #002664 | #002664 | `blue-04`, `blue-01` |
+| `surface` | On Surface | #22272B | white | #22272B | `grey-01`*, `white` |
+
+*Note: source uses #22272B, our grey-01 is #3D3D3D. Close enough for now — revisit if the NSW DS specifies #22272B.
+
+### Variant × Colour behaviour
+- **Primary**: filled background, white or dark text
+- **Secondary**: transparent bg, 2px border, coloured text
+- **Tertiary**: no fill, no border, coloured text (ghost)
+
+## Sizes
+
+| Size | Height | Padding | Typography |
+|---|---|---|---|
+| Default | 48px | 24px horizontal | Body Strong (16/24 bold) |
+| Comfortable | 40px | 20px horizontal | Body Strong (16/24 bold) |
+| Compact | 36px | 16px horizontal | Small Strong (14/19 bold) |
+
+## Shared Styling
+- Border radius: `rounded-full` (pill shape, 9999px)
+- Icon size: 24px (default), 20px (compact)
+- Content gap: 8px
+- Focus ring: 2px border offset (matches example's "Border" layer)
+- Disabled: opacity 50%, cursor not-allowed
+
+## Hover/Active States
+- **Primary**: overlay with white at ~10% opacity (hover), ~20% (active)
+- **Secondary/Tertiary**: bg fill at ~5% opacity (hover), ~10% (active)
+- Implementation: CSS `hover:` and `active:` with bg-opacity modifiers
+
+## Build Order
+1. Add tokens (if needed) to tokens.css
+2. Build React component + stories
+3. Build Figma component on Components page (rebind to our variables)
+4. Code Connect link
+5. addon-designs embed in story
+
+## Questions resolved
+- All four colour schemes included
+- Icon slots as ReactNode
+- No dark mode
diff --git a/src/components/ui/Button/Button.stories.tsx b/src/components/ui/Button/Button.stories.tsx
index d08c071..357ca0d 100644
--- a/src/components/ui/Button/Button.stories.tsx
+++ b/src/components/ui/Button/Button.stories.tsx
@@ -8,40 +8,179 @@ const meta: Meta<typeof Button> = {
   argTypes: {
     variant: {
       control: 'select',
-      options: ['primary', 'secondary', 'danger'],
+      options: ['primary', 'secondary', 'tertiary'],
+    },
+    color: {
+      control: 'select',
+      options: ['navy', 'red', 'light', 'surface'],
     },
     size: {
       control: 'select',
-      options: ['sm', 'md', 'lg'],
+      options: ['default', 'comfortable', 'compact'],
     },
     disabled: { control: 'boolean' },
     children: { control: 'text' },
   },
+  parameters: {
+    design: {
+      type: 'figma',
+      url: 'https://www.figma.com/design/mrabO6AtxN3ektGiTk0I9c/ResearchInsights?node-id=10-20',
+    },
+  },
 }
 
 export default meta
 type Story = StoryObj<typeof meta>
 
-export const Primary: Story = {
-  args: { children: 'Primary Button', variant: 'primary' },
+export const Default: Story = {
+  args: { children: 'Button' },
 }
 
-export const Secondary: Story = {
-  args: { children: 'Secondary Button', variant: 'secondary' },
+export const PrimaryNavy: Story = {
+  args: { children: 'Button', variant: 'primary', color: 'navy' },
 }
 
-export const Danger: Story = {
-  args: { children: 'Delete', variant: 'danger' },
+export const PrimaryRed: Story = {
+  args: { children: 'Delete', variant: 'primary', color: 'red' },
 }
 
-export const Small: Story = {
-  args: { children: 'Small', size: 'sm' },
+export const PrimaryLight: Story = {
+  args: { children: 'Button', variant: 'primary', color: 'light' },
 }
 
-export const Large: Story = {
-  args: { children: 'Large', size: 'lg' },
+export const PrimarySurface: Story = {
+  args: { children: 'Button', variant: 'primary', color: 'surface' },
+}
+
+export const SecondaryNavy: Story = {
+  args: { children: 'Button', variant: 'secondary', color: 'navy' },
+}
+
+export const SecondaryRed: Story = {
+  args: { children: 'Cancel', variant: 'secondary', color: 'red' },
+}
+
+export const SecondarySurface: Story = {
+  args: { children: 'Button', variant: 'secondary', color: 'surface' },
+}
+
+export const TertiaryNavy: Story = {
+  args: { children: 'Button', variant: 'tertiary', color: 'navy' },
+}
+
+export const TertiaryRed: Story = {
+  args: { children: 'Remove', variant: 'tertiary', color: 'red' },
+}
+
+export const TertiarySurface: Story = {
+  args: { children: 'Button', variant: 'tertiary', color: 'surface' },
+}
+
+const ArrowIcon = () => (
+  <svg
+    xmlns="http://www.w3.org/2000/svg"
+    viewBox="0 0 24 24"
+    fill="none"
+    stroke="currentColor"
+    strokeWidth={2}
+    strokeLinecap="round"
+    strokeLinejoin="round"
+  >
+    <path d="M5 12h14" />
+    <path d="m12 5 7 7-7 7" />
+  </svg>
+)
+
+const LockIcon = () => (
+  <svg
+    xmlns="http://www.w3.org/2000/svg"
+    viewBox="0 0 24 24"
+    fill="none"
+    stroke="currentColor"
+    strokeWidth={2}
+    strokeLinecap="round"
+    strokeLinejoin="round"
+  >
+    <rect width="18" height="11" x="3" y="11" rx="2" ry="2" />
+    <path d="M7 11V7a5 5 0 0 1 10 0v4" />
+  </svg>
+)
+
+export const WithLeftIcon: Story = {
+  args: { children: 'Button', leftIcon: <LockIcon /> },
+}
+
+export const WithRightIcon: Story = {
+  args: { children: 'Button', rightIcon: <ArrowIcon /> },
+}
+
+export const WithBothIcons: Story = {
+  args: {
+    children: 'Button',
+    leftIcon: <LockIcon />,
+    rightIcon: <ArrowIcon />,
+  },
+}
+
+export const Comfortable: Story = {
+  args: { children: 'Button', size: 'comfortable' },
+}
+
+export const Compact: Story = {
+  args: { children: 'Button', size: 'compact' },
+}
+
+export const AllSizes: Story = {
+  render: () => (
+    <div className="flex items-center gap-4">
+      <Button size="default">Default</Button>
+      <Button size="comfortable">Comfortable</Button>
+      <Button size="compact">Compact</Button>
+    </div>
+  ),
+}
+
+export const AllVariants: Story = {
+  render: () => (
+    <div className="flex items-center gap-4">
+      <Button variant="primary">Primary</Button>
+      <Button variant="secondary">Secondary</Button>
+      <Button variant="tertiary">Tertiary</Button>
+    </div>
+  ),
+}
+
+export const AllColours: Story = {
+  render: () => (
+    <div className="flex flex-col gap-4">
+      <div className="flex items-center gap-4">
+        <Button color="navy">Navy</Button>
+        <Button color="red">Red</Button>
+        <Button color="light">Light</Button>
+        <Button color="surface">Surface</Button>
+      </div>
+      <div className="flex items-center gap-4">
+        <Button variant="secondary" color="navy">Navy</Button>
+        <Button variant="secondary" color="red">Red</Button>
+        <Button variant="secondary" color="light">Light</Button>
+        <Button variant="secondary" color="surface">Surface</Button>
+      </div>
+      <div className="flex items-center gap-4">
+        <Button variant="tertiary" color="navy">Navy</Button>
+        <Button variant="tertiary" color="red">Red</Button>
+        <Button variant="tertiary" color="light">Light</Button>
+        <Button variant="tertiary" color="surface">Surface</Button>
+      </div>
+    </div>
+  ),
 }
 
 export const Disabled: Story = {
-  args: { children: 'Disabled', disabled: true },
+  render: () => (
+    <div className="flex items-center gap-4">
+      <Button disabled>Primary</Button>
+      <Button variant="secondary" disabled>Secondary</Button>
+      <Button variant="tertiary" disabled>Tertiary</Button>
+    </div>
+  ),
 }
diff --git a/src/components/ui/Button/Button.tsx b/src/components/ui/Button/Button.tsx
index 84244ad..c5b0a26 100644
--- a/src/components/ui/Button/Button.tsx
+++ b/src/components/ui/Button/Button.tsx
@@ -2,30 +2,82 @@ import { forwardRef, type ButtonHTMLAttributes } from 'react'
 import { cn } from '@/lib/utils'
 
 export interface ButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
-  variant?: 'primary' | 'secondary' | 'danger'
-  size?: 'sm' | 'md' | 'lg'
+  variant?: 'primary' | 'secondary' | 'tertiary'
+  color?: 'navy' | 'red' | 'light' | 'surface'
+  size?: 'default' | 'comfortable' | 'compact'
+  leftIcon?: React.ReactNode
+  rightIcon?: React.ReactNode
+}
+
+const variantColorStyles: Record<string, Record<string, string>> = {
+  primary: {
+    navy: 'bg-blue-01 text-white hover:bg-blue-01/90 active:bg-blue-01/80',
+    red: 'bg-red-02 text-white hover:bg-red-02/90 active:bg-red-02/80',
+    light: 'bg-blue-04 text-blue-01 hover:bg-blue-04/80 active:bg-blue-04/60',
+    surface: 'bg-grey-01 text-white hover:bg-grey-01/90 active:bg-grey-01/80',
+  },
+  secondary: {
+    navy: 'border-2 border-blue-01 text-blue-01 hover:bg-blue-01/5 active:bg-blue-01/10',
+    red: 'border-2 border-red-02 text-red-02 hover:bg-red-02/5 active:bg-red-02/10',
+    light: 'border-2 border-blue-01 text-blue-01 hover:bg-blue-01/5 active:bg-blue-01/10',
+    surface: 'border-2 border-grey-01 text-grey-01 hover:bg-grey-01/5 active:bg-grey-01/10',
+  },
+  tertiary: {
+    navy: 'text-blue-01 hover:bg-blue-01/5 active:bg-blue-01/10',
+    red: 'text-red-02 hover:bg-red-02/5 active:bg-red-02/10',
+    light: 'text-blue-01 hover:bg-blue-01/5 active:bg-blue-01/10',
+    surface: 'text-grey-01 hover:bg-grey-01/5 active:bg-grey-01/10',
+  },
+}
+
+const sizeStyles: Record<string, string> = {
+  default: 'h-12 px-6 text-body gap-2',
+  comfortable: 'h-10 px-5 text-body gap-2',
+  compact: 'h-9 px-4 text-small gap-1.5',
+}
+
+const iconSizeStyles: Record<string, string> = {
+  default: 'size-6',
+  comfortable: 'size-5',
+  compact: 'size-5',
 }
 
 export const Button = forwardRef<HTMLButtonElement, ButtonProps>(
-  ({ className, variant = 'primary', size = 'md', children, ...props }, ref) => {
+  (
+    {
+      variant = 'primary',
+      color = 'navy',
+      size = 'default',
+      leftIcon,
+      rightIcon,
+      disabled,
+      className,
+      children,
+      ...props
+    },
+    ref,
+  ) => {
     return (
       <button
         ref={ref}
+        disabled={disabled}
         className={cn(
-          'inline-flex items-center justify-center font-medium rounded-default transition-colors',
-          'focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-primary',
-          'disabled:opacity-50 disabled:cursor-not-allowed',
-          variant === 'primary' && 'bg-primary text-white hover:bg-primary-hover',
-          variant === 'secondary' && 'bg-surface text-text border border-border hover:bg-bg',
-          variant === 'danger' && 'bg-error text-white hover:bg-red-700',
-          size === 'sm' && 'px-3 py-1.5 text-sm',
-          size === 'md' && 'px-4 py-2 text-base',
-          size === 'lg' && 'px-6 py-3 text-lg',
+          'inline-flex items-center justify-center rounded-full font-bold transition-colors',
+          'focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-blue-01',
+          sizeStyles[size],
+          variantColorStyles[variant][color],
+          disabled && 'pointer-events-none opacity-50',
           className,
         )}
         {...props}
       >
+        {leftIcon && (
+          <span className={cn('shrink-0', iconSizeStyles[size])}>{leftIcon}</span>
+        )}
         {children}
+        {rightIcon && (
+          <span className={cn('shrink-0', iconSizeStyles[size])}>{rightIcon}</span>
+        )}
       </button>
     )
   },