[css-values-4] Specify that <angle>s must clamp to a multiple of 360deg. #6105

Author: tabatkins

css-values-4/Overview.bs

@@ -962,6 +962,10 @@ Numeric Data Types</h2>
 	it must be converted to the closest value supported by the implementation,
 	but how the implementation defines "closest" is explicitly undefined as well.
 
+	If an <<angle>> must be converted
+	due to exceeding the implementation-defined range of supported values,
+	it must be clamped to the nearest supported multiple of ''360deg''.
+
 <h3 id="numeric-ranges">
 Range Restrictions and Range Definition Notation</h3>