```
**Colour contrast (minimum 4.5:1 for normal text):**
```css
/* Incorrect: insufficient contrast */
.text { color: #999; background: #fff; } /* Ratio: 2.85:1 */
/* Correct: sufficient contrast */
.text { color: #595959; background: #fff; } /* Ratio: 7.0:1 */
```
### 2. Operable
Interface components must be operable.
**Keyboard navigation:**
```html
```
**Minimum touch target size (WCAG 2.2):**
```css
/* Buttons must be at least 44x44px for touch */
.button {
min-height: 44px;
min-width: 44px;
padding: 12px 24px;
}
```
### 3. Understandable
Information and the operation of the interface must be understandable.
**Page language:**
```html
```
**Form labels:**
```html
```
### 4. Robust
Content must be robust enough to be interpreted by assistive technologies.
**Correct use of ARIA roles:**
```html
Page title
| Feature | Starter | Professional | Enterprise |
|---|---|---|---|
| Included contacts | 1,000 | 2,000 | 10,000 |
| Automations | ✗ | ✓ | ✓ |
