<!DOCTYPE html>
<meta name="viewport" content="width=device-width, minimum-scale=0.25">
<style>
html {
  overflow: hidden;
}
html, body {
  margin: 0;
  width: 100%;
  height: 100%;
}
div {
  position: absolute;
}
</style>
<!--
  Even if minimum-scale=0.25 is specified, the widest element in this content is
  below div element whose *real* width is 200% because of `margin-left: -500%`,
  so this content should be scaled to 0.5x.
  -->
<div style="background: green; width: 700%; height: 500%; margin-left: -500%;"></div>
<div style="background: blue; width: 100%; height: 100%;"></div>