Merge remote-tracking branch 'origin/master' into refactor/checkbox_test

Author: joyzhong

packages/mdc-card/README.md

@@ -150,7 +150,7 @@ and the [optional modifier classes](#css-classes).
 
 #### Actions
 
-This area is used for showing different actions the user can take, typically at the bottom of a card.
+This area is used to show different actions the user can take, typically at the bottom of a card.
 It's often used with [buttons](../mdc-button):
 
 ```html

packages/mdc-card/_mixins.scss

@@ -46,9 +46,13 @@
   $feat-color: mdc-feature-create-target($query, color);
   $feat-structure: mdc-feature-create-target($query, structure);
 
+  @include mdc-elevation-overlay-common($query);
+
   .mdc-card {
     @include mdc-card-shape-radius(medium, $query: $query);
     @include mdc-card-fill-color(surface, $query);
+    @include mdc-elevation-overlay-surface-position($query: $query);
+    @include mdc-elevation-overlay-dimensions(100%, $query: $query);
     @include mdc-elevation(1, $query: $query);
 
     @include mdc-feature-targets($feat-structure) {