[css-ui-4] Fix links

Author: frivoal

css-ui-4/Overview.bs

@@ -406,7 +406,7 @@ Applies to: all elements
 Inherited: no
 Percentages: N/A
 Media: visual
-Computed value: The computed value for ''invert'' is ''invert''.
+Computed value: The computed value for ''outline-color/invert'' is ''outline-color/invert''.
  For <<color>> values, see <a>resolving color values</a> in [[!CSS-COLOR-4]].
 Animation Type: <a href="https://drafts.csswg.org/css3-transitions/#animtype-color">color</a>
 </pre>
@@ -466,15 +466,15 @@ User agents may treat ''outline-style/auto'' as
 ''outline-style/solid''.
 
 The 'outline-color' property
-accepts all colors, as well as the keyword <dfn>invert</dfn>.
-''Invert'' is expected to perform a color inversion on the pixels on the screen.
+accepts all colors, as well as the keyword <dfn dfn-type=value dfn-for=outline-color>invert</dfn>.
+''outline-color/invert'' is expected to perform a color inversion on the pixels on the screen.
 This is a common trick to ensure the focus border is visible,
 regardless of color background.
 
-Conformant UAs may ignore the ''invert'' value
+Conformant UAs may ignore the ''outline-color/invert'' value
 on platforms that do not support color inversion of the pixels on the screen.
 
-If the UA does not support the ''invert'' value
+If the UA does not support the ''outline-color/invert'' value
 then it must reject that value at parse-time, and
 the initial value of the 'outline-color' property
 is the ''color/currentColor'' keyword.