[css-env-1] fix bikeshed errors

Author: tabatkins

css-env-1/Overview.bs

@@ -3,13 +3,19 @@ Title: CSS Environment Variables Module Level 1
 Shortname: css-env
 Level: 1
 Status: UD
+Work Status: exploring
 Group: CSSWG
 URL: https://drafts.csswg.org/css-env-1/
 Editor: Tab Atkins-Bittner, Google
 Editor: Dean Jackson, Apple
 Abstract: This specification defines the concept of [=environment variables=] and the ''env()'' function, which work similarly to custom properties and the ''var()'' function, but are defined globally for a document. These can be defined either by the User Agent, providing values that can be used on the page based on information the UA has special access to, or provided by the author for "global" variables that are guaranteed to be the same no matter where in the document they're used.
 </pre>
 
+<pre class=link-defaults>
+spec:dom; type:interface; text:Document
+spec:css-variables-1; type:dfn; text:invalid at computed-value time
+</pre>
+
 Introduction {#intro}
 =====================
 
@@ -98,7 +104,7 @@ and in several other places where CSS values are allowed.
 The first argument to ''env()'' provides the name of an [=environment variable=] to be substituted.
 The second argument, if provided, is a fallback value,
 which is used as the substitution value
-when the referenced [=environment value=] does not exist.
+when the referenced [=environment variable=] does not exist.
 
 Note: The syntax of the fallback, like that of custom properties, allows commas.
 For example, ''env(foo, red, blue)'' defines a fallback of ''red, blue'';