styles.css

/**
 *
 * Copyright 2016 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  background: #E2E2E2;
  overflow-x: hidden;
  overflow-y: scroll;
}

sc-card {
  width: 260px;
  height: 380px;
  position: relative;
  perspective: 500px;
  will-change: transform;
}

sc-card .front,
sc-card .back {
  backface-visibility: hidden;
  position: absolute;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 3px;
  overflow: hidden;
}

sc-card button {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: none;
  border: none;
  text-indent: -10000px;
  /*display: none;*/
}

sc-card .front {
  background: #444;
  color: #FFF;
}

sc-card .front h1 {
  font-size: 24px;
}

sc-card .back {
  background: url(images/supercharged.jpg) center center no-repeat;
  color: #FFF;
  transform: rotateY(180deg);
}

sc-card .umbra,
sc-card .penumbra {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  backface-visibility: visible;
}

sc-card .umbra {
  width: 270px;
  height: 390px;
  top: -5px;
  left: -5px;
  background: url(images/umbra.svg) center center no-repeat;
  transform: translateY(2px);
  opacity: 0.3;
}

sc-card .penumbra {
  width: 330px;
  height: 450px;
  top: -35px;
  left: -35px;
  background: url(images/penumbra.svg) center center no-repeat;
  transform: translateY(2px);
  opacity: 0;
}