body {
  font: 400 14px Arial;
}

.content {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  height: 100%;
}

.header {
  width: 500px;
  height: 20px;
  margin: auto auto 0;
  padding-bottom: .5rem;
}

.right {
  float: right;
}

.zoom-button:after {
  padding-left: .25rem;
  content: attr(data-scale);
}

.container {
  display: flex;
  justify-content: center;
  width: 500px;
  height: 500px;
  overflow: hidden;
  border: 1px solid gray;
  margin: 0 auto auto;
}

img {
  position: relative;
  max-height: 100%;
  will-change: transform;
}