scrollbar-width dl dfn-for, length in dl

fix dl dfn-for, and explicitly list all values for scrollbar-width in dl

Author: tantek

css-scrollbars-1/Overview.bs

@@ -33,8 +33,6 @@ and as has been increasingly adopted
 on the web since Windows IE 5.5 introduced it in 2000.
 [Note: Add citations of examples from Bugzilla 77790 and webcompat].
 
-Should we add scrollbar width? (<a href="https://github.com/w3c/csswg-drafts/issues/1958">Issue 1958</a>)
-
 Out of scope: 
 <a href="https://www.w3.org/wiki/Css-scrollbars#Why_not_pseudos">pseudo-elements for selecting specific parts of a scrollbar are unnecesssary</a>
 for the documented use-cases and are thus out of scope for this specification.
@@ -76,11 +74,14 @@ Note: Unlike 'overflow' (and overflow-*) properties,
 scrollbar-* values set on the HTML body element are not propagated to the viewport.
 
 <dl dfn-type="value" dfn-for="scrollbar-face-color">
-<dt><dfn>auto</dfn>
+<dt><dfn>auto</dfn></dt>
 <dd>default platform rendering for that portion of the scrollbar, in the absence of any other 
-related scrollbar color properties. See details below for which scrollbar color are related to which.
-<dt><dfn><<color>></dfn>
+related scrollbar color properties.
+See details below for which scrollbar color are related to which.
+</dd>
+<dt><dfn><<color>></dfn></dt>
 <dd>apply the color to that portion of the scrollbar, and potentially other portions of the scrollbar.
+</dd>
 </dl>
 
 Details:
@@ -138,27 +139,26 @@ Media: visual
 </pre>
 
 This property allows the author to set the maximum thickness of an element’s scrollbars when they are shown.
-Negative <<length>> values are not allowed.
-
-When a user agent displays one or more scrollbars for an element, 
-the thickness of those scrollbars must be no more than the computed 'scrollbar-width' value.
-
-<dl for=scrollbar-width>
 
+<dl dfn-type="value" dfn-for=scrollbar-width>
 <dt><dfn >''auto''</dfn></dt>
-<dd>implementations must use the default platform scrollbar width.</dd>
-
+<dd>implementations must use the default platform scrollbar width.
+</dd>
 <dt><dfn for=scrollbar-width>''thin''</dfn></dt>
 <dd>implementations must use either a thin scrollbar width variant on platforms that provide that option, 
-or display a scrollbar thinner than the default platform scrollbar width.</dd>
-
-</dl>
-
-Note: If scrollbar-width computes to 0, the element’s scrollbars are hidden, 
+or display a scrollbar thinner than the default platform scrollbar width.
+</dd>
+<dt><dfn><<length>></dfn></dt>
+<dd>When a user agent displays one or more scrollbars for an element, 
+the thickness of those scrollbars must be no more than the computed 'scrollbar-width' length value.
+Negative <<length>> values are not allowed. If scrollbar-width computes to 0, the element’s scrollbars are hidden, 
 however its scrollability is not affected.
+</dd>
+</dl>
 
 Note: There is working group disagreement about whether to allow length values, 
 or only have keywords (auto, thin, none), or drop the scrollbar-width property altogether.
+(<a href="https://github.com/w3c/csswg-drafts/issues/1958">Issue 1958</a>)
 
 UAs must apply the scrollbar-width value set on the root element to the viewport.