chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css

/**
 * Copyright (c) 2012 The Chromium Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

body {
  margin: 5px 10px 10px;
}

h1 {
  color: #53637D;
  font: 26px/1.2 Helvetica, sans-serif;
  font-size: 200%;
  margin: 0;
  padding-bottom: 4px;
  text-shadow: white 0 1px 2px;
}

label {
  color: #222;
  font: 18px/1.4 Helvetica, sans-serif;
  margin: 0.5em 0;
  display: inline-block;
}

form {
  width: 563px;
  -webkit-transition: -webkit-transform 0.25s ease;
}

button {
  display: block;
  border-radius: 2px;
  box-shadow: 0px 1px 3px rgba(0, 0, 0, 0.1);
  -webkit-user-select: none;
  background: -webkit-linear-gradient(#FAFAFA, #F4F4F4 40%, #E5E5E5);
  border: 1px solid #AAA;
  color: #444;
  margin-bottom: 0;
  min-width: 4em;
  padding: 3px 12px;
  margin-top: 0;
  font-size: 1.1em;
}

.overlay {
  display: block;
  text-align: center;
  position: absolute;
  left: 50%;
  top: 50%;
  width: 500px;
  padding: 20px;
  margin: -40px 0 0 -270px;
  opacity: 0;
  background: rgba(0, 0, 0, 0.75);
  border-radius: 5px;
  color: #FFF;
  font: 1.5em/1.2 Helvetica Neue, sans-serif;
  -webkit-transition: all 1.0s ease;
  -webkit-transform: scale(0);
}

.overlay a {
  color:  #FFF;
}

.overlay.visible {
  opacity: 1;
  -webkit-transform: scale(1);
}