refactor: remove unused and duplicate CSS properties from styleguide examples (angular#28252)

PR Close angular#28252

Author: DanielRuf

aio/content/examples/styleguide/src/04-11/app/core/nav/nav.component.css

@@ -32,8 +32,6 @@
   height: 56px;
   padding: 0 16px 0 72px;
   padding-left: 8px;
-  background-color: #673AB7;
-  background: #0033FF;
   background-color: #222;
 }
 

aio/content/examples/styleguide/src/04-11/app/core/spinner/spinner.component.css

@@ -1,6 +1,5 @@
 /*#docregion*/
 .spinner {
-  position: absolute;
   left: 7em;
   top: 20em;
   position: absolute;

aio/content/examples/styleguide/src/04-12/app/core/nav/nav.component.css

@@ -32,8 +32,6 @@
   height: 56px;
   padding: 0 16px 0 72px;
   padding-left: 8px;
-  background-color: #673AB7;
-  background: #0033FF;
   background-color: #222;
 }
 

aio/src/styles/2-modules/_toc.scss

@@ -138,9 +138,7 @@ aio-toc.embedded {
       }
 
       a {
-        font-size: inherit;
         color: lighten($darkgray, 10);
-        display:table-cell;
         overflow: visible;
         font-size: 12px;
         display: table-cell;