penpot/frontend/resources/styles/main/partials/viewer.scss

.viewer-content {
  background-color: black;

  display: grid;
  grid-template-rows: 232px auto;
  grid-template-columns: 1fr;
}

.viewer-preview {
  height: 100vh;

  grid-row: 1 / span 2;
  grid-column: 1 / span 1;

  overflow: scroll;

  display: flex;
  justify-content: center;
  align-items: center;
  flex-flow: wrap;

  svg {
    transform-origin: center;
  }
}