diff --git a/browser/extensions/pdfjs/README.mozilla b/browser/extensions/pdfjs/README.mozilla
index 5aed5e6bbd43..460eb90cb677 100644
--- a/browser/extensions/pdfjs/README.mozilla
+++ b/browser/extensions/pdfjs/README.mozilla
@@ -1,3 +1,3 @@
 This is the pdf.js project output, https://github.com/mozilla/pdf.js
 
-Current extension version is: 1.7.348
+Current extension version is: 1.7.359
diff --git a/browser/extensions/pdfjs/content/build/pdf.js b/browser/extensions/pdfjs/content/build/pdf.js
index 008b6769e6e3..8ceba30465c0 100644
--- a/browser/extensions/pdfjs/content/build/pdf.js
+++ b/browser/extensions/pdfjs/content/build/pdf.js
@@ -3667,8 +3667,8 @@ var _UnsupportedManager = function UnsupportedManagerClosure() {
   }
  };
 }();
-exports.version = '1.7.348';
-exports.build = '754c4bd0';
+exports.version = '1.7.359';
+exports.build = 'd471e356';
 exports.getDocument = getDocument;
 exports.PDFDataRangeTransport = PDFDataRangeTransport;
 exports.PDFWorker = PDFWorker;
@@ -4685,8 +4685,8 @@ if (!globalScope.PDFJS) {
  globalScope.PDFJS = {};
 }
 var PDFJS = globalScope.PDFJS;
-PDFJS.version = '1.7.348';
-PDFJS.build = '754c4bd0';
+PDFJS.version = '1.7.359';
+PDFJS.build = 'd471e356';
 PDFJS.pdfBug = false;
 if (PDFJS.verbosity !== undefined) {
  sharedUtil.setVerbosityLevel(PDFJS.verbosity);
@@ -7186,8 +7186,8 @@ exports.TilingPattern = TilingPattern;
 
 "use strict";
 
-var pdfjsVersion = '1.7.348';
-var pdfjsBuild = '754c4bd0';
+var pdfjsVersion = '1.7.359';
+var pdfjsBuild = 'd471e356';
 var pdfjsSharedUtil = __w_pdfjs_require__(0);
 var pdfjsDisplayGlobal = __w_pdfjs_require__(8);
 var pdfjsDisplayAPI = __w_pdfjs_require__(3);
diff --git a/browser/extensions/pdfjs/content/build/pdf.worker.js b/browser/extensions/pdfjs/content/build/pdf.worker.js
index 3493e908f812..251ff312ff1a 100644
--- a/browser/extensions/pdfjs/content/build/pdf.worker.js
+++ b/browser/extensions/pdfjs/content/build/pdf.worker.js
@@ -35026,6 +35026,9 @@ var WidgetAnnotation = function WidgetAnnotationClosure() {
    var loopDict = dict;
    while (loopDict.has('Parent')) {
     loopDict = loopDict.get('Parent');
+    if (!isDict(loopDict)) {
+     break;
+    }
     if (loopDict.has('T')) {
      fieldName.unshift(stringToPDFString(loopDict.get('T')));
     }
@@ -49129,8 +49132,8 @@ exports.Type1Parser = Type1Parser;
 
 "use strict";
 
-var pdfjsVersion = '1.7.348';
-var pdfjsBuild = '754c4bd0';
+var pdfjsVersion = '1.7.359';
+var pdfjsBuild = 'd471e356';
 var pdfjsCoreWorker = __w_pdfjs_require__(17);
 ;
 exports.WorkerMessageHandler = pdfjsCoreWorker.WorkerMessageHandler;
diff --git a/browser/extensions/pdfjs/content/web/viewer.css b/browser/extensions/pdfjs/content/web/viewer.css
index 3f5c28b6232a..0c015f00c097 100644
--- a/browser/extensions/pdfjs/content/web/viewer.css
+++ b/browser/extensions/pdfjs/content/web/viewer.css
@@ -532,8 +532,7 @@ html[dir='rtl'] #toolbarContainer, .findbar, .secondaryToolbar {
   top: 32px;
   position: absolute;
   z-index: 10000;
-  height: 32px;
-
+  height: auto;
   min-width: 16px;
   padding: 0px 6px 0px 6px;
   margin: 4px 2px 4px 2px;
@@ -544,10 +543,21 @@ html[dir='rtl'] #toolbarContainer, .findbar, .secondaryToolbar {
   cursor: default;
 }
 
+.findbar {
+  min-width: 300px;
+}
+.findbar > div {
+  height: 32px;
+}
+.findbar.wrapContainers > div {
+  clear: both;
+}
+.findbar.wrapContainers > div#findbarMessageContainer {
+  height: auto;
+}
 html[dir='ltr'] .findbar {
   left: 68px;
 }
-
 html[dir='rtl'] .findbar {
   right: 68px;
 }
@@ -556,6 +566,15 @@ html[dir='rtl'] .findbar {
   -moz-user-select: none;
 }
 
+#findInput {
+  width: 200px;
+}
+#findInput::-moz-placeholder {
+  font-style: italic;
+}
+#findInput::placeholder {
+  font-style: italic;
+}
 #findInput[data-status="pending"] {
   background-image: url(images/loading-small.png);
   background-repeat: no-repeat;
@@ -646,6 +665,9 @@ html[dir='ltr'] .doorHangerRight:before {
   font-style: italic;
   color: #A6B7D0;
 }
+#findMsg:empty {
+  display: none;
+}
 
 #findInput.notFound {
   background-color: rgb(255, 102, 102);
@@ -668,14 +690,14 @@ html[dir='rtl'] #toolbarViewerLeft {
 html[dir='ltr'] #toolbarViewerLeft > *,
 html[dir='ltr'] #toolbarViewerMiddle > *,
 html[dir='ltr'] #toolbarViewerRight > *,
-html[dir='ltr'] .findbar > * {
+html[dir='ltr'] .findbar * {
   position: relative;
   float: left;
 }
 html[dir='rtl'] #toolbarViewerLeft > *,
 html[dir='rtl'] #toolbarViewerMiddle > *,
 html[dir='rtl'] #toolbarViewerRight > *,
-html[dir='rtl'] .findbar > * {
+html[dir='rtl'] .findbar * {
   position: relative;
   float: right;
 }
@@ -719,10 +741,6 @@ html[dir='rtl'] .splitToolbarButton > .toolbarButton {
   opacity: .5;
 }
 
-.toolbarButton.group {
-  margin-right: 0;
-}
-
 .splitToolbarButton.toggled .toolbarButton {
   margin: 0;
 }
@@ -2041,7 +2059,7 @@ html[dir='rtl'] #documentPropertiesOverlay .row > * {
 }
 
 @media all and (max-width: 640px) {
-  .hiddenSmallView {
+  .hiddenSmallView, .hiddenSmallView * {
     display: none;
   }
   .visibleSmallView {
@@ -2050,6 +2068,12 @@ html[dir='rtl'] #documentPropertiesOverlay .row > * {
   .toolbarButtonSpacer {
     width: 0;
   }
+  html[dir='ltr'] .findbar {
+    left: 38px;
+  }
+  html[dir='rtl'] .findbar {
+    right: 38px;
+  }
 }
 
 @media all and (max-width: 535px) {
diff --git a/browser/extensions/pdfjs/content/web/viewer.html b/browser/extensions/pdfjs/content/web/viewer.html
index 17ac030aa9eb..29e4afddb0b9 100644
--- a/browser/extensions/pdfjs/content/web/viewer.html
+++ b/browser/extensions/pdfjs/content/web/viewer.html
@@ -48,13 +48,13 @@ See https://github.com/adobe-type-tools/cmap-resources
       <div id="sidebarContainer">
         <div id="toolbarSidebar">
           <div class="splitToolbarButton toggled">
-            <button id="viewThumbnail" class="toolbarButton group toggled" title="Show Thumbnails" tabindex="2" data-l10n-id="thumbs">
+            <button id="viewThumbnail" class="toolbarButton toggled" title="Show Thumbnails" tabindex="2" data-l10n-id="thumbs">
                <span data-l10n-id="thumbs_label">Thumbnails</span>
             </button>
-            <button id="viewOutline" class="toolbarButton group" title="Show Document Outline (double-click to expand/collapse all items)" tabindex="3" data-l10n-id="document_outline">
+            <button id="viewOutline" class="toolbarButton" title="Show Document Outline (double-click to expand/collapse all items)" tabindex="3" data-l10n-id="document_outline">
                <span data-l10n-id="document_outline_label">Document Outline</span>
             </button>
-            <button id="viewAttachments" class="toolbarButton group" title="Show Attachments" tabindex="4" data-l10n-id="attachments">
+            <button id="viewAttachments" class="toolbarButton" title="Show Attachments" tabindex="4" data-l10n-id="attachments">
                <span data-l10n-id="attachments_label">Attachments</span>
             </button>
           </div>
@@ -70,24 +70,31 @@ See https://github.com/adobe-type-tools/cmap-resources
       </div>  <!-- sidebarContainer -->
 
       <div id="mainContainer">
-        <div class="findbar hidden doorHanger hiddenSmallView" id="findbar">
-          <label for="findInput" class="toolbarLabel" data-l10n-id="find_label">Find:</label>
-          <input id="findInput" class="toolbarField" tabindex="91">
-          <div class="splitToolbarButton">
-            <button class="toolbarButton findPrevious" title="" id="findPrevious" tabindex="92" data-l10n-id="find_previous">
-              <span data-l10n-id="find_previous_label">Previous</span>
-            </button>
-            <div class="splitToolbarButtonSeparator"></div>
-            <button class="toolbarButton findNext" title="" id="findNext" tabindex="93" data-l10n-id="find_next">
-              <span data-l10n-id="find_next_label">Next</span>
-            </button>
+        <div class="findbar hidden doorHanger" id="findbar">
+          <div id="findbarInputContainer">
+            <input id="findInput" class="toolbarField" title="Find" placeholder="Find in document" tabindex="91" data-l10n-id="find_input">
+            <div class="splitToolbarButton">
+              <button class="toolbarButton findPrevious" title="" id="findPrevious" tabindex="92" data-l10n-id="find_previous">
+                <span data-l10n-id="find_previous_label">Previous</span>
+              </button>
+              <div class="splitToolbarButtonSeparator"></div>
+              <button class="toolbarButton findNext" title="" id="findNext" tabindex="93" data-l10n-id="find_next">
+                <span data-l10n-id="find_next_label">Next</span>
+              </button>
+            </div>
+          </div>
+
+          <div id="findbarOptionsContainer">
+            <input type="checkbox" id="findHighlightAll" class="toolbarField" tabindex="94">
+            <label for="findHighlightAll" class="toolbarLabel" data-l10n-id="find_highlight">Highlight all</label>
+            <input type="checkbox" id="findMatchCase" class="toolbarField" tabindex="95">
+            <label for="findMatchCase" class="toolbarLabel" data-l10n-id="find_match_case_label">Match case</label>
+            <span id="findResultsCount" class="toolbarLabel hidden"></span>
+          </div>
+
+          <div id="findbarMessageContainer">
+            <span id="findMsg" class="toolbarLabel"></span>
           </div>
-          <input type="checkbox" id="findHighlightAll" class="toolbarField" tabindex="94">
-          <label for="findHighlightAll" class="toolbarLabel" data-l10n-id="find_highlight">Highlight all</label>
-          <input type="checkbox" id="findMatchCase" class="toolbarField" tabindex="95">
-          <label for="findMatchCase" class="toolbarLabel" data-l10n-id="find_match_case_label">Match case</label>
-          <span id="findResultsCount" class="toolbarLabel hidden"></span>
-          <span id="findMsg" class="toolbarLabel"></span>
         </div>  <!-- findbar -->
 
         <div id="secondaryToolbar" class="secondaryToolbar hidden doorHangerRight">
@@ -152,10 +159,10 @@ 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 group hiddenSmallView" title="Find in Document" tabindex="12" data-l10n-id="findbar">
+                <button id="viewFind" class="toolbarButton" title="Find in Document" tabindex="12" data-l10n-id="findbar">
                    <span data-l10n-id="findbar_label">Find</span>
                 </button>
-                <div class="splitToolbarButton">
+                <div class="splitToolbarButton hiddenSmallView">
                   <button class="toolbarButton pageUp" title="Previous Page" id="previous" tabindex="13" data-l10n-id="previous">
                     <span data-l10n-id="previous_label">Previous</span>
                   </button>
diff --git a/browser/extensions/pdfjs/content/web/viewer.js b/browser/extensions/pdfjs/content/web/viewer.js
index 765f52e6d530..5e57a3be1a1c 100644
--- a/browser/extensions/pdfjs/content/web/viewer.js
+++ b/browser/extensions/pdfjs/content/web/viewer.js
@@ -3896,10 +3896,7 @@ var PDFAttachmentViewer = function PDFAttachmentViewerClosure() {
  PDFAttachmentViewer.prototype = {
   reset: function PDFAttachmentViewer_reset(keepRenderedCapability) {
    this.attachments = null;
-   var container = this.container;
-   while (container.firstChild) {
-    container.firstChild.remove();
-   }
+   this.container.textContent = '';
    if (!keepRenderedCapability) {
     this._renderedCapability = pdfjsLib.createPromiseCapability();
    }
@@ -4187,6 +4184,7 @@ var PDFFindBar = function PDFFindBarClosure() {
   this.caseSensitive.addEventListener('click', function () {
    self.dispatchEvent('casesensitivitychange');
   });
+  this.eventBus.on('resize', this._adjustWidth.bind(this));
  }
  PDFFindBar.prototype = {
   reset: function PDFFindBar_reset() {
@@ -4233,6 +4231,7 @@ var PDFFindBar = function PDFFindBarClosure() {
    this.findField.setAttribute('data-status', status);
    this.findMsg.textContent = findMsg;
    this.updateResultsCount(matchCount);
+   this._adjustWidth();
   },
   updateResultsCount: function (matchCount) {
    if (!this.findResultsCount) {
@@ -4253,6 +4252,7 @@ var PDFFindBar = function PDFFindBarClosure() {
    }
    this.findField.select();
    this.findField.focus();
+   this._adjustWidth();
   },
   close: function PDFFindBar_close() {
    if (!this.opened) {
@@ -4269,6 +4269,17 @@ var PDFFindBar = function PDFFindBarClosure() {
    } else {
     this.open();
    }
+  },
+  _adjustWidth: function PDFFindBar_adjustWidth() {
+   if (!this.opened) {
+    return;
+   }
+   this.bar.classList.remove('wrapContainers');
+   var findbarHeight = this.bar.clientHeight;
+   var inputContainerHeight = this.bar.firstElementChild.clientHeight;
+   if (findbarHeight > inputContainerHeight) {
+    this.bar.classList.add('wrapContainers');
+   }
   }
  };
  return PDFFindBar;
@@ -4596,10 +4607,8 @@ var PDFOutlineViewer = function PDFOutlineViewerClosure() {
   reset: function PDFOutlineViewer_reset() {
    this.outline = null;
    this.lastToggleIsShow = true;
-   var container = this.container;
-   while (container.firstChild) {
-    container.firstChild.remove();
-   }
+   this.container.textContent = '';
+   this.container.classList.remove('outlineWithDeepNesting');
   },
   _dispatchEvent: function PDFOutlineViewer_dispatchEvent(outlineCount) {
    this.eventBus.dispatch('outlineloaded', {
diff --git a/browser/locales/en-US/pdfviewer/viewer.properties b/browser/locales/en-US/pdfviewer/viewer.properties
index da5442c68bda..27939c13bb64 100644
--- a/browser/locales/en-US/pdfviewer/viewer.properties
+++ b/browser/locales/en-US/pdfviewer/viewer.properties
@@ -121,7 +121,8 @@ thumb_page_title=Page {{page}}
 thumb_page_canvas=Thumbnail of Page {{page}}
 
 # Find panel button title and messages
-find_label=Find:
+find_input.title=Find
+find_input.placeholder=Find in document…
 find_previous.title=Find the previous occurrence of the phrase
 find_previous_label=Previous
 find_next.title=Find the next occurrence of the phrase