More styling improvements.

src/Squidex/app/theme/_mixins.scss

@@ -24,11 +24,16 @@
         color: $color;
     }
 
-    &:disabled {
+    &:disabled
+    &.disabled {
         @include opacity(.4);
-    }
-
+    }  
+    
     &:focus,
+    &.focus {
+        @include box-shadow-raw(0 0 0 $btn-focus-width rgba($color, .5));
+    }
+    
     &:active,
     &:hover {
         color: darken($color, 8%);

src/Squidex/wwwroot/theme.html

@@ -134,6 +134,7 @@
                         <button type="button" class="btn btn-info">Info</button>
                         <button type="button" class="btn btn-warning">Warning</button>
                         <button type="button" class="btn btn-danger">Danger</button>
+                        <a class="btn btn-link">Link</a>
                     </p>
 
                     <p class="bs-component">
@@ -1295,7 +1296,7 @@
 
                 <div class="row">
                     <div class="col-lg-6">
-                        <h2>Dark</h2>
+                        <h2>Light</h2>
                         <div class="bs-component">
                             <div class="panel panel-light">
                                 <div class="panel-header">