chrome/browser/resources/pdf/pdf_embedder.css

/* Copyright 2025 The Chromium Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file. */

body {
  height: 100%;
  width: 100%;
  overflow: hidden;
  margin: 0;
  /* LINT.IfChange(PdfBackgroundColor) */
  background-color: rgb(40, 40, 40);
  /* LINT.ThenChange(//chrome/browser/resources/pdf/pdf_viewer.ts:PdfBackgroundColor, //components/pdf/common/pdf_util.cc:PdfBackgroundColor) */
}

iframe {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 100%;
  border-style: none;
}