Material PDF: Style audit and cleanup

chrome/browser/resources/pdf/elements/viewer-pdf-toolbar/viewer-pdf-toolbar.css

 /* Copyright 2015 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. */
 
 /* We introduce a wrapper aligner element as setting the relevant attributes
  * (horizontal justified layout center) have no effect on the core-toolbar. */
 #aligner {
   width: 100%;
 }
 
 #title {
+  font-size: 77.8%;
+  font-weight: 500;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
 }
 
 #pageselector-container {
   text-align: center;
   /* The container resizes according to the width of the toolbar. On small
    * screens with large numbers of pages, overflow page numbers without
    * wrapping. */
   white-space: nowrap;
 }
 
 #buttons {
+  -webkit-user-select: none;
   text-align: right;
 }
 
-#buttons > paper-icon-button {
-  margin-right: 8px;
+paper-icon-button {
+  margin-right: 12px;
 }
 
 viewer-toolbar-dropdown {
   margin-right: 4px;
 }
 
 paper-progress {
-  height: 56px;
-  position: absolute;
-  width: 100%;
-  z-index: 3;
-}
-
-paper-progress {
   --paper-progress-active-color: rgb(50, 54, 57);
   --paper-progress-container-color: rgb(34, 36, 38);
+  height: 48px;
+  position: absolute;
+  width: 100%;
 }
 
 paper-toolbar {
+  @apply(--shadow-elevation-2dp);
   background-color: transparent;
   color: rgb(241, 241, 241);
   font-size: 1.5em;
-  height: 56px;
-  padding-left: 1em;
-  padding-right: 1em;
-  z-index: 3;
+  height: 48px;
+  padding: 0 16px;
 }
 
 paper-toolbar /deep/ ::selection {
   background: rgba(255, 255, 255, 0.3);
 }
 
 paper-toolbar /deep/ .toolbar-tools {
-  height: 56px;
+  height: 48px;
 }
 
 .invisible {
   visibility: hidden;
 }