* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  overscroll-behavior: none;
}

html,
body,
iframe {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

iframe {
  flex-shrink: 1;
  max-height: 100%;
  max-width: 100%;
  min-height: 0;
  min-width: 0;
}