Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components/paper-card/paper-card.html

+<!--
+Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+
+<!--
+
+`paper-card` is a container that renders two shadows on top of each other to
+create the effect of a lifted piece of paper.
+
+Example:
+
+    <paper-card elevation="1">
+      ... card content ...
+    </paper-card>
+
+@group Paper Elements
+@class paper-card
+-->
+
+<link href="../polymer/polymer.html" rel="import">
+<link href="../paper-styles/shadow.html" rel="import">
+<dom-module id="paper-card">
+  <style>
+    :host {
+      display: block;
+      position: relative;
+      mixin(--shadow-transition);
+    }
+
+    :host([elevation="1"]) {
+      mixin(--shadow-elevation-1);
+    }
+
+    :host([elevation="2"]) {
+      mixin(--shadow-elevation-2);
+    }
+
+    :host([elevation="3"]) {
+      mixin(--shadow-elevation-3);
+    }
+
+    :host([elevation="4"]) {
+      mixin(--shadow-elevation-4);
+    }
+
+    :host([elevation="5"]) {
+      mixin(--shadow-elevation-5);
+    }
+  </style>
+  <template>
+    <content></content>
+  </template>
+</dom-module>
+<script>
+  Polymer({
+    is: 'paper-card',
+
+    enableCustomStyleProperties: true,
+
+    properties: {
+
+      /**
+       * The z-depth of this card, from 0-5. Setting to 0 will remove the
+       * shadow, and each increasing number greater than 0 will be "deeper"
+       * than the last.
+       *
+       * @attribute elevation
+       * @type number
+       * @default 1
+       */
+      elevation: {
+        type: Number,
+        reflectToAttribute: true,
+        value: 1
+      },
+
+      /**
+       * Set this to true to animate the shadow when setting a new
+       * `elevation` value.
+       *
+       * @attribute animated
+       * @type boolean
+       * @default false
+       */
+      animated: {
+        type: Boolean,
+        reflectToAttribute: true,
+        value: false
+      }
+    }
+  });
+</script>