html, body { min-height: 100%; }

.site {
  display: grid;
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
}

.nhsuk-main-wrapper.main--flush {
  padding: 0;
  min-height: 0;
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.viewer-shell {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
}

.viewer-actions {
  padding: 16px 24px;
  flex: 0 0 auto;
}

.viewer-frame {
  flex: 1 1 auto;
  width: 100%;
  height: 100%;
  min-height: 0;
  border: 0;
  display: block;
}