diff --git a/web/web/viewer.html b/web/web/viewer.html
index 10b8cc0..0c85ba5 100644
--- a/web/web/viewer.html
+++ b/web/web/viewer.html
@@ -161,7 +161,7 @@ See https://github.com/adobe-type-tools/cmap-resources
 				  <span data-l10n-id="toggle_sidebar_label">Toggle Sidebar</span>
 				</button>
 				<div class="toolbarButtonSpacer"></div>
-				<button id="viewFind" class="toolbarButton" title="Find in Document" tabindex="12" data-l10n-id="findbar" style="display: none;">
+				<button id="viewFind" class="toolbarButton" title="Find in Document" tabindex="12" data-l10n-id="findbar" hidden="true">
 				  <span data-l10n-id="findbar_label">Find</span>
 				</button>
 				<div class="splitToolbarButton hiddenSmallView">
@@ -181,24 +181,24 @@ See https://github.com/adobe-type-tools/cmap-resources
 				  <span data-l10n-id="presentation_mode_label">Presentation Mode</span>
 				</button>
 
-				<button id="openFile" class="toolbarButton openFile hiddenLargeView" title="Open File" tabindex="32" data-l10n-id="open_file" style="display: none;">
+				<button id="openFile" class="toolbarButton openFile hiddenLargeView" title="Open File" tabindex="32" data-l10n-id="open_file" hidden="true">
 				  <span data-l10n-id="open_file_label">Open</span>
 				</button>
 
-				<button id="print" class="toolbarButton print hiddenMediumView" title="Print" tabindex="33" data-l10n-id="print" style="display: none;">
+				<button id="print" class="toolbarButton print hiddenMediumView" title="Print" tabindex="33" data-l10n-id="print" hidden="true">
 				  <span data-l10n-id="print_label">Print</span>
 				</button>
 
-				<button id="download" class="toolbarButton download hiddenMediumView" title="Download" tabindex="34" data-l10n-id="download" style="display: none;">
+				<button id="download" class="toolbarButton download hiddenMediumView" title="Download" tabindex="34" data-l10n-id="download" hidden="true">
 				  <span data-l10n-id="download_label">Download</span>
 				</button>
-				<a href="#" id="viewBookmark" class="toolbarButton bookmark hiddenSmallView" title="Current view (copy or open in new window)" tabindex="35" data-l10n-id="bookmark" style="display: none;">
+				<a href="#" id="viewBookmark" class="toolbarButton bookmark hiddenSmallView" title="Current view (copy or open in new window)" tabindex="35" data-l10n-id="bookmark" hidden="true">
 				  <span data-l10n-id="bookmark_label">Current View</span>
 				</a>
 
 				<div class="verticalToolbarSeparator hiddenSmallView"></div>
 
-				<button id="secondaryToolbarToggle" class="toolbarButton" title="Tools" tabindex="36" data-l10n-id="tools" style="display: none;">
+				<button id="secondaryToolbarToggle" class="toolbarButton" title="Tools" tabindex="36" data-l10n-id="tools" hidden="true">
 				  <span data-l10n-id="tools_label">Tools</span>
 				</button>
 			  </div>