Required field warning covers input field

This issue is partially due to my use of floats in the form, but the span containing the error message “Please fill the required field” was covering the entire enclosing div, preventing the user from clicking on the input field to fix the error.

Switching the span to inline or inline-block fixed the issue. Shouldn’t that be the default style? Or maybe a clear: both?

span.wpcf7-not-valid-tip {
  display: inline-block;
}