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 {
  padding: 0;
  margin: 0;
  background-color: #FAFAFA;
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: 'Roboto', Arial, sans-serif;
}

body {
  display: flex;
  flex-direction: column;
}

.header {
  width: 100%;
  height: 56px;
  color: #FFF;
  background: #607D8B;
  font-size: 20px;
  box-shadow: 0 4px 5px 0 rgba(0,0,0,.14),
      0 2px 9px 1px rgba(0,0,0,.12),
      0 4px 2px -2px rgba(0,0,0,.2);
  padding: 16px 16px 0;
  position: relative;
  z-index: 1;
}

.header__title {
  font-weight: 400;
  font-size: 20px;
  margin: 0;
}

.main {
  flex: 1;
  padding: 16px;
  overflow-x: hidden;
  overflow-y: scroll;
  position: relative;
  width: 100%;
  display: flex;
  justify-content: space-around;
}

.main img {
  width: 100%;
  max-width: 650px;
  cursor: zoom-in;
}

.zoomer {
  width: 1px;
  height: 1px;
  position: fixed;
  left: 0;
  top: 0;
  pointer-events: none;
}

.zoomer__canvas {
  position: absolute;
  left: -64px;
  top: -134px;
}