- Use `Element.layout` as the top-level function to render the `elm-ui` element tree — it replaces `Html.div` at the root.
- Use `Element.row` and `Element.column` for layout — never use raw CSS flexbox or grid classes alongside `elm-ui`.
- Apply spacing with `Element.spacing` and `Element.padding` attributes — never use margin hacks or CSS `px` strings.
- Use `Element.Input.text`, `Element.Input.button`, and `Element.Input.checkbox` for accessible interactive elements with built-in label support.