Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components/paper-styles/layout.html

+<!--
+@license
+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
+-->
+
+<link rel="import" href="../polymer/polymer.html">
+
+<link rel="import" href="classes/layout.html">
+
+<style is="x-style">
+
+  * {
+
+    --layout: {
+      display: -ms-flexbox;
+      display: -webkit-flex;
+      display: flex;
+    }
+
+    --layout-horizontal: {
+      display: -ms-flexbox;
+      display: -webkit-flex;
+      display: flex;
+
+      -ms-flex-direction: row;
+      -webkit-flex-direction: row;
+      flex-direction: row;
+    }
+
+    --layout-vertical: {
+      display: -ms-flexbox;
+      display: -webkit-flex;
+      display: flex;
+
+      -ms-flex-direction: column;
+      -webkit-flex-direction: column;
+      flex-direction: column;
+    }
+
+    --layout-flex: {
+      -ms-flex: 1;
+      -webkit-flex: 1;
+      flex: 1;
+    }
+
+    --layout-center: {
+      -ms-flex-align: center;
+      -webkit-align-items: center;
+      align-items: center;
+    }
+
+    --layout-center-justified: {
+      -ms-flex-pack: center;
+      -webkit-justify-content: center;
+      justify-content: center;
+    }
+
+    /*******************************
+              Other Layout
+    *******************************/
+
+    --fit: {
+      position: absolute;
+      top: 0;
+      right: 0;
+      bottom: 0;
+      left: 0;
+    }
+
+  }
+
+</style>