[css-egg-1] Added random units

Author: SebastianZ

css-egg-1/Overview.bs

@@ -430,6 +430,37 @@ This feature is useful for designing robust content that adapts to different dev
 
 This API may be used for gleaning information about the user's environment, which may be used to fingerprint them. This is recognized to be an acceptable loss for the momentous benefits this API is expected to provide the web platform.
 
+<h3 id="random">Random values</h3>
+
+[[CSS-VALUES-5]] introduces ''random()'' to generate random values.
+
+As that function has very limited use cases,
+this specification introduces three <dfn>random value units</dfn> covering a broader range of randomness.
+
+<table class="data" export>
+	<thead>
+		<tr><th>unit
+		    <th>name
+		    <th>definition
+	<tbody>
+		<tr><th><dfn style="white-space: nowrap">🎲</dfn>
+		    <td>Random number
+		    <td>Returns a random <<number>> value between ''0'' and the given <<number>> value.
+		<tr><th><dfn style="white-space: nowrap">🎲🎲</dfn>
+		    <td>Random number and unit
+		    <td>Returns a random <<dimension>> or <<percentage>> between ''0'' and the given value.
+		<tr><th><dfn style="white-space: nowrap">❓</dfn>
+		    <td>Random value
+		    <td>Returns a <<number>>, <<dimension>>, or <<percentage>> between ''0'' and the given value,
+		        a <<color>>, <<string>>, or any kind of <a href="https://drafts.csswg.org/css-values-4/#keywords">pre-defined keyword</a>.
+		<tr><th><dfn style="white-space: nowrap">🎁</dfn>
+		    <td>Complete randomness
+		    <td>May return any kind of value defined in [[CSS-VALUES-5]],
+		        including but not limited to <<number>>, <<dimension>>, or <<percentage>> values of any size,
+		        a <<color>>, <<string>>, any kind of <<ident>>, or nothing at all.
+		        It might even come up with new values not yet defined. Who knows?
+</table>
+
 
 <h2 id="rainbow">
 Double Rainbow</h2>