All input fields follow the same basic rules:
Label and body text: Arial
Mandatory fields are marked by an asterisk at the end of the field label and an indicator bar at the right end of the input field.
For incorrect inputs:
The error status shown under the element. This should be concise but explanatory.
When focussed, an element has an outline of #F7A70B
Buttons are used to change state of data e.g. to submit responses to a form. They should be solid filled with no icons (only CTAs have the chevron on the right)