style.css

/**
 * @license
 * Copyright 2019 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */
/* [START maps_directions_panel] */
/* Optional: Makes the sample page fill the window. */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#container {
  height: 100%;
  display: flex;
}

#sidebar {
  flex-basis: 15rem;
  flex-grow: 1;
  padding: 1rem;
  max-width: 30rem;
  height: 100%;
  box-sizing: border-box;
  overflow: auto;
}

#map {
  flex-basis: 0;
  flex-grow: 4;
  height: 100%;
}

#floating-panel {
  position: absolute;
  top: 10px;
  left: 25%;
  z-index: 5;
  background-color: #fff;
  padding: 5px;
  border: 1px solid #999;
  text-align: center;
  font-family: "Roboto", "sans-serif";
  line-height: 30px;
  padding-left: 10px;
}

#floating-panel {
  background-color: #fff;
  border: 0;
  border-radius: 2px;
  box-shadow: 0 1px 4px -1px rgba(0, 0, 0, 0.3);
  margin: 10px;
  padding: 0 0.5em;
  font: 400 18px Roboto, Arial, sans-serif;
  overflow: hidden;
  padding: 5px;
  font-size: 14px;
  text-align: center;
  line-height: 30px;
  height: auto;
}

#map {
  flex: auto;
}

#sidebar {
  flex: 0 1 auto;
  padding: 0;
}
#sidebar > div {
  padding: 0.5rem;
}

/* [END maps_directions_panel] */