[css-sizing-3]] Tweak wording to be a bit more specific to sizes of boxes.

Author: fantasai

css-sizing-3/Overview.bs

@@ -607,8 +607,10 @@ Inner vs Outer Sizes: the 'box-sizing' property</h3>
 	<a lt="min height">minimum (min) height</a>,
 	<a lt="max width">maximum (max) width</a>, and
 	<a lt="max height">maximum (max) height</a>
-	refer to the <a lt="inner size">inner</a> (<a>content box</a>) size
-	unless otherwise specified.
+	refer to the <a lt="inner size">inner</a> size
+	(<a lt="content box">content-box</a> size)
+	of a <a>box</a>
+	unless otherwise indicated.
 
 
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