Known issues

• One small condition is hard-coded to avoid white color for pen. This can be removed with an isolated state
• Persisting the last chosen Pen color is also a good UX feature that can be added
• The Highlighter does not have color support as of yet but can be added very easily combined with isolated state
• The canvas does not resize when the viewport resizes. This can be achieved by attaching resize events on the component

Demo: https://reverent-hopper-b8b33f.netlify.app/