Age Calculator (HTML / CSS / Javascript)

What did you find difficult while building the project?

• figuring out the validators and manipulating the DOM to render error elements

Which areas of your code are you unsure of?

• my calculator does simple age calculations which doesnt factor in leap year etc.

Do you have any questions about best practices?

• Would love some feedback on how to make the input focus etc.
• also how to animate output number when calculated. That would be cool to learn.

Any constructive feedback would be appreciated!