diff --git a/public/404.html b/public/404.html
index 1661bdb379..fb80975aef 100644
--- a/public/404.html
+++ b/public/404.html
@@ -17,34 +17,24 @@
 
   <body>
 
-    <nav id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
+    <header id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
       <div class="container">
         <div class="navbar-header">
           <a class="navbar-brand ml-lg-5" id="brand" href="/">Public Lab</a>
         </div>
       </div>
-    </nav>
+    </header>
 
+    <main>
     <div class="container">
-
       <div class="row">
-
 <!-- ################################################ -->
-
-        <div class="col-md-3">
-
-        </div>
-
+        <div class="col-md-3"> </div>
         <div class="col-md-9">
-
           <h1>That page does not exist.</h1>
-
           <p>Are you sure you've typed the right address?</p>
-
           <hr>
-
           <p>Please help us figure out what happened so we can fix it!</p>
-
           <p>If possible, please describe:</p>
 
           <ul>
@@ -56,27 +46,21 @@ <h1>That page does not exist.</h1>
           </ul>
 
           <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new">Report a bug on Github</a> or send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
-
           <p>Thank you for helping to improve open source software!.</p>
 
           <hr>
 
           <h2>Ask for help in the Public Lab chatroom</h2>
-
           <p>Community members and staff may be able to help you in real time.</p>
-
           <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
 
         </div>
-
 <!-- ################################################ -->
-
       </div><!--/row-->
-
     </div><!--/.fluid-container-->
+    </main>
 
     <footer class="footer">
-
       <div class="col-md-3 hidden-print">
         <h4>Getting help</h4>
         <ul>
@@ -121,6 +105,7 @@ <h4>Links</h4>
         }
       })()
     </script>
+    
     <script type="text/javascript">
 
       var _gaq = _gaq || [];
@@ -138,5 +123,6 @@ <h4>Links</h4>
       })();
 
     </script>
+
   </body>
 </html>
diff --git a/public/422.html b/public/422.html
index edac31af85..b07c0fd387 100644
--- a/public/422.html
+++ b/public/422.html
@@ -17,35 +17,28 @@
 
   <body>
 
-
-      <nav id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
+    <header id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
         <div class="container">
           <div class="navbar-header">
             <a class="navbar-brand ml-lg-5" id="brand" href="/">Public Lab</a>
           </div>
         </div>
-      </nav>
+    </header>
 
+    <main>
     <div class="container">
-
       <div class="row">
-
 <!-- ################################################ -->
-
         <div class="col-md-3">
-
         </div>
 
         <div class="col-md-9">
-
           <h2>There was a problem with your request. <small>Are you sure you have permissions to do that?</small></h2>
-
           <p>Or it may be our servers!</p>
 
           <hr>
 
           <p>Please help us figure out what happened so we can fix it!</p>
-
           <p>If possible, please describe:</p>
 
           <ul>
@@ -57,27 +50,22 @@ <h2>There was a problem with your request. <small>Are you sure you have permissi
           </ul>
 
           <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new">Report a bug on Github</a> or send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
-
           <p>Thank you for helping to improve open source software!.</p>
 
           <hr>
 
           <h2>Ask for help in the Public Lab chatroom</h2>
-
           <p>Community members and staff may be able to help you in real time.</p>
-
           <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
 
         </div>
-
 <!-- ################################################ -->
-
       </div><!--/row-->
 
     </div><!--/.fluid-container-->
+    </main>
 
     <footer class="footer">
-
       <div class="col-md-3 hidden-print">
         <h4>Getting help</h4>
         <ul>
@@ -122,6 +110,7 @@ <h4>Links</h4>
         }
       })()
     </script>
+    
     <script type="text/javascript">
 
       var _gaq = _gaq || [];
@@ -139,5 +128,6 @@ <h4>Links</h4>
       })();
 
     </script>
+
   </body>
 </html>
diff --git a/public/500.html b/public/500.html
index fae1737c71..7b493bdfd9 100644
--- a/public/500.html
+++ b/public/500.html
@@ -17,69 +17,55 @@
 
   <body>
 
-
-    <nav id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
+    <header id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
       <div class="container">
         <div class="navbar-header">
           <a class="navbar-brand ml-lg-5" id="brand" href="/">Public Lab</a>
         </div>
       </div>
-    </nav>
-
-    <div class="container">
-
-      <div class="row">
-
-<!-- ################################################ -->
-
-        <div class="col-md-3">
-
-        </div>
-
-        <div class="col-md-9">
-
-          <h2>There was an error. <small>Are you sure you have the right address?</small></h2>
-
-          <hr>
-
-          <p>If your browser is set to a language besides English, please <a href="/change_locale/en">click here to switch to English</a> while we resolve a bug -- apologies!</p>
-
-          <hr>
-
-          <p>Please help us figure out what happened so we can fix it!</p>
-
-          <p>If possible, please describe:</p>
+    </header>
 
-          <ul>
-            <li>what you did just before the problem occurred</li>
-            <li>your browser and browser version</li>
-            <li>your operating system</li>
-            <li>any web addresses needed to see the problem (such as the URL of this page)</li>
-            <li>your PublicLab.org username (if you have one)</li>
-          </ul>
-
-          <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new" target="_blank">Report a bug on Github</a> <a class="btn btn-primary" href="https://oss.skylight.io/app/applications/GZDPChmcfm1Q/recent/6h/endpoints" target="_blank">Check if the site is running slow</a> or, send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
-
-          <p>Thank you for helping to improve open source software!.</p>
-
-          <hr>
-
-          <h2>Ask for help in the Public Lab chatroom</h2>
-
-          <p>Community members and staff may be able to help you in real time.</p>
-
-          <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
-
-        </div>
-
-<!-- ################################################ -->
-
-      </div><!--/row-->
-
-    </div><!--/.fluid-container-->
+    <main>
+      <div class="container">
+        <div class="row">
+  <!-- ################################################ -->
+          <div class="col-md-3">
+          </div>
+  
+          <div class="col-md-9">
+            <h2>There was an error. <small>Are you sure you have the right address?</small></h2>
+  
+            <hr>
+  
+            <p>If your browser is set to a language besides English, please <a href="/change_locale/en">click here to switch to English</a> while we resolve a bug -- apologies!</p>
+            <hr>
+  
+            <p>Please help us figure out what happened so we can fix it!</p>
+            <p>If possible, please describe:</p>
+  
+            <ul>
+              <li>what you did just before the problem occurred</li>
+              <li>your browser and browser version</li>
+              <li>your operating system</li>
+              <li>any web addresses needed to see the problem (such as the URL of this page)</li>
+              <li>your PublicLab.org username (if you have one)</li>
+            </ul>
+  
+            <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new" target="_blank">Report a bug on Github</a> <a class="btn btn-primary" href="https://oss.skylight.io/app/applications/GZDPChmcfm1Q/recent/6h/endpoints" target="_blank">Check if the site is running slow</a> or, send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
+            <p>Thank you for helping to improve open source software!.</p>
+  
+            <hr>
+  
+            <h2>Ask for help in the Public Lab chatroom</h2>
+            <p>Community members and staff may be able to help you in real time.</p>
+            <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
+          </div>
+  <!-- ################################################ -->
+        </div><!--/row-->
+      </div><!--/.fluid-container-->
+    </main>
 
     <footer class="footer">
-
       <div class="col-md-3 hidden-print">
         <h4>Getting help</h4>
         <ul>
@@ -124,6 +110,7 @@ <h4>Links</h4>
         }
       })()
     </script>
+    
     <script type="text/javascript">
 
       var _gaq = _gaq || [];
@@ -141,5 +128,6 @@ <h4>Links</h4>
       })();
 
     </script>
+
   </body>
 </html>
diff --git a/public/502.html b/public/502.html
index ff09f38cd1..42ffa6ed85 100644
--- a/public/502.html
+++ b/public/502.html
@@ -19,34 +19,27 @@
   <body>
 
 
-    <nav id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
+    <header id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
       <div class="container">
         <div class="navbar-header">
           <a class="navbar-brand ml-lg-5" id="brand" href="/">Public Lab</a>
         </div>
       </div>
-    </nav>
+    </header>
 
+    <main>
     <div class="container">
-
       <div class="row">
-
 <!-- ################################################ -->
-
         <div class="col-md-3">
-
         </div>
-
         <div class="col-md-9">
-
           <h2>This page is taking too long to load.</h2>
-
           <p>We're sorry! Please try refreshing the page.</p>
 
           <hr>
 
           <p>If the problem continues, please help us figure out what happened so we can fix it!</p>
-
           <p>If possible, please describe:</p>
 
           <ul>
@@ -56,27 +49,20 @@ <h2>This page is taking too long to load.</h2>
           </ul>
 
           <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new">Report a bug on Github</a> or send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
-
           <p>Thank you for helping to improve open source software!.</p>
 
           <hr>
 
           <h2>Ask for help in the Public Lab chatroom</h2>
-
           <p>Community members and staff may be able to help you in real time.</p>
-
           <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
-
         </div>
-
 <!-- ################################################ -->
-
       </div><!--/row-->
-
     </div><!--/.fluid-container-->
+    </main>
 
     <footer class="footer">
-
       <div class="col-md-3 hidden-print">
         <h4>Getting help</h4>
         <ul>
@@ -121,6 +107,7 @@ <h4>Links</h4>
         }
       })()
     </script>
+    
     <script type="text/javascript">
 
       var _gaq = _gaq || [];
@@ -138,5 +125,6 @@ <h4>Links</h4>
       })();
 
     </script>
+
   </body>
 </html>
diff --git a/public/503.html b/public/503.html
index 3c6acd57b5..46df54cddc 100644
--- a/public/503.html
+++ b/public/503.html
@@ -19,64 +19,51 @@
   <body>
 
 
-    <nav id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
+    <header id="header" class="navbar navbar-dark bg-dark fixed-top mb-5 py-3">
       <div class="container">
         <div class="navbar-header">
           <a class="navbar-brand ml-lg-5" id="brand" href="/">Public Lab</a>
         </div>
       </div>
-    </nav>
+    </header>
 
-    <div class="container">
-
-      <div class="row">
-
-<!-- ################################################ -->
-
-        <div class="col-md-3">
-
-        </div>
-
-        <div class="col-md-9">
-
-          <h2>Our website is having some trouble.</h2>
-
-          <p>See <a href="https://oss.skylight.io/app/applications/GZDPChmcfm1Q/1536553680/12h/endpoints">our monitoring graphs</a> to see what's going on.</p>
-
-          <hr>
-
-          <p>Please help us figure out what happened so we can fix it!</p>
-
-          <p>If possible, please describe:</p>
-
-          <ul>
-            <li>what you did just before the problem occurred</li>
-            <li>any web addresses needed to see the problem (such as the URL of this page)</li>
-            <li>your PublicLab.org username (if you have one)</li>
-          </ul>
-
-          <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new">Report a bug on Github</a> or send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
-
-          <p>Thank you for helping to improve open source software!.</p>
-
-          <hr>
-
-          <h2>Ask for help in the Public Lab chatroom</h2>
-
-          <p>Community members and staff may be able to help you in real time.</p>
-
-          <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
-
-        </div>
-
-<!-- ################################################ -->
-
-      </div><!--/row-->
-
-    </div><!--/.fluid-container-->
+    <main>
+      <div class="container">
+        <div class="row">
+  <!-- ################################################ -->
+          <div class="col-md-3">
+          </div>
+          <div class="col-md-9">
+            <h2>Our website is having some trouble.</h2>
+            <p>See <a href="https://oss.skylight.io/app/applications/GZDPChmcfm1Q/1536553680/12h/endpoints">our monitoring graphs</a> to see what's going on.</p>
+  
+            <hr>
+  
+            <p>Please help us figure out what happened so we can fix it!</p>
+            <p>If possible, please describe:</p>
+  
+            <ul>
+              <li>what you did just before the problem occurred</li>
+              <li>any web addresses needed to see the problem (such as the URL of this page)</li>
+              <li>your PublicLab.org username (if you have one)</li>
+            </ul>
+  
+            <p><a class="btn btn-primary" href="https://github.com/publiclab/plots2/issues/new">Report a bug on Github</a> or send an email to <a href="mailto:web@publiclab.org">web@publiclab.org</a> with the above information.</p>
+            <p>Thank you for helping to improve open source software!.</p>
+  
+            <hr>
+  
+            <h2>Ask for help in the Public Lab chatroom</h2>
+            <p>Community members and staff may be able to help you in real time.</p>
+            <p><a href="https://publiclab.org/chat" target="_blank" class="btn btn-primary">Open chatroom</a></p>
+  
+          </div>
+  <!-- ################################################ -->
+        </div><!--/row-->
+      </div><!--/.fluid-container-->
+    </main>
 
     <footer class="footer">
-
       <div class="col-md-3 hidden-print">
         <h4>Getting help</h4>
         <ul>
@@ -121,6 +108,7 @@ <h4>Links</h4>
         }
       })()
     </script>
+    
     <script type="text/javascript">
 
       var _gaq = _gaq || [];
