diff --git a/amanuensis/resources/editor.css b/amanuensis/resources/editor.css
index fb0e52b..2ccbbaa 100644
--- a/amanuensis/resources/editor.css
+++ b/amanuensis/resources/editor.css
@@ -17,7 +17,7 @@ div#editor-left {
 	display: flex;
 	align-items: stretch;
 }
-div#editor-left div.contentblock {
+div#editor-left section {
 	display: flex;
 	flex-direction: column;
 	margin: 10px 5px 10px 10px;
@@ -48,7 +48,7 @@ textarea#editor-content {
 div#editor-right {
 	overflow-y: scroll;
 }
-div#editor-right div.contentblock {
+div#editor-right section {
 	margin: 10px 5px 10px 10px;
 }
 span.message-warning {
diff --git a/amanuensis/resources/page.css b/amanuensis/resources/page.css
index bffd77b..8e68a98 100644
--- a/amanuensis/resources/page.css
+++ b/amanuensis/resources/page.css
@@ -8,14 +8,14 @@ body {
 	line-height: 1.4;
 	font-size: 16px;
 }
-div#wrapper {
+main {
 	max-width: 800px;
 	position: absolute;
 	left: 0;
 	right: 0;
 	margin: 0 auto;
 }
-div#header {
+header {
 	padding: 5px;
 	margin: 5px;
 	background-color: #ffffff;
@@ -24,7 +24,7 @@ div#header {
 	overflow: auto;
 	position: relative;
 }
-div#header p, div#header h2 {
+header p, header h2 {
 	margin: 5px;
 }
 div#login-status {
@@ -33,7 +33,7 @@ div#login-status {
 	top: 10px;
 	right: 10px;
 }
-div#sidebar {
+nav {
 	width: 200px;
 	float:left;
 	margin:5px;
@@ -46,7 +46,7 @@ div#sidebar {
 img#logo {
 	max-width: 200px;
 }
-div#sidebar table {
+nav table {
 	width: 100%;
 	border-collapse: collapse;
 }
@@ -63,32 +63,32 @@ table a {
 	border-radius: 5px;
 	text-decoration: none;
 }
-div#sidebar table a {
+nav table a {
 	justify-content: center;
 }
 table a:hover {
 	background-color: var(--button-hover);
 }
-div#sidebar table a.current-page {
+nav table a.current-page {
 	background-color: var(--button-current);
 }
-div#sidebar table a.current-page:hover {
+nav table a.current-page:hover {
 	background-color: var(--button-current);
 }
-div#sidebar table td {
+nav table td {
 	padding: 0px; margin: 3px 0;
 	border-bottom: 8px solid transparent;
 }
-div#content {
+article {
 	margin: 5px;
 }
-div.content-2col {
+article.content-2col {
 	position: absolute;
 	right: 0px;
 	left: 226px;
 	max-width: 564px;
 }
-div.contentblock {
+section {
 	background-color: #ffffff;
 	box-shadow: 2px 2px 10px #888888;
 	margin-bottom: 5px;
@@ -216,26 +216,26 @@ details.setting-help {
 	width: 4em;
 }
 @media only screen and (max-width: 816px) {
-	div#wrapper {
+	main {
 		padding: 5px;
 	}
-	div#header {
+	header {
 		max-width: 554px;
 		margin: 0 auto;
 	}
-	div#sidebar {
+	nav {
 		max-width: 548px;
 		width: inherit;
 		float: inherit;
 		margin: 10px auto;
 	}
-	div#content{
+	article{
 		margin: 10px auto;
 	}
-	div.content-1col {
+	article.content-1col {
 		max-width: 564px;
 	}
-	div.content-2col {
+	article.content-2col {
 		max-width: 564px;
 		position: static;
 		right: inherit;
diff --git a/amanuensis/server/page.jinja b/amanuensis/server/page.jinja
index 5b45466..df4832e 100644
--- a/amanuensis/server/page.jinja
+++ b/amanuensis/server/page.jinja
@@ -8,8 +8,8 @@
     <link rel="stylesheet" href="{{ url_for('static', filename='page.css') }}">
 </head>
 <body>
-    <div id="wrapper">
-        <div id="header">
+    <main>
+        <header>
             <div id="login-status" {% block login_status_attr %}{% endblock %}>
                 {% if current_user.is_authenticated %}
                 <b>{{ current_user.username -}}</b>
@@ -24,15 +24,15 @@
                 {% endif %}
             </div>
             {% block header %}{% endblock %}
-        </div>
+        </header>
         {% block sidebar %}{% endblock %}
-        <div id="content" class="{% block content_class %}{% endblock %}">
+        <article class="{% block content_class %}{% endblock %}">
             {% if not template_content_blocks %}{% set template_content_blocks = [] %}{% endif %}
             {% if not content_blocks %}{% set content_blocks = [] %}{% endif %}
-            {% for content_block in template_content_blocks + content_blocks %}<div class="contentblock">
-                {{ content_block|safe }}</div>
+            {% for content_block in template_content_blocks + content_blocks -%}
+            <section>{{ content_block|safe }}</div>
             {% endfor %}
-        </div>
-    </div>
+        </article>
+    </main>
 </body>
 </html>
diff --git a/amanuensis/server/page_2col.jinja b/amanuensis/server/page_2col.jinja
index dac4d32..6bce71e 100644
--- a/amanuensis/server/page_2col.jinja
+++ b/amanuensis/server/page_2col.jinja
@@ -1,12 +1,12 @@
 {% extends "page.jinja" %}
 {% block sidebar %}
-<div id="sidebar">
+<nav>
     {% if not template_sidebar_rows %}{% set template_sidebar_rows = [] %}{% endif %}
     {% if not sidebar_rows %}{% set sidebar_rows = [] %}{% endif %}
     <table>
         {% for row in template_sidebar_rows + sidebar_rows %}
         <tr><td>{{ row|safe }}</td></tr>{% endfor %}
     </table>
-</div>
+</nav>
 {% endblock %}
 {% block content_class %}content-2col{% endblock %}
\ No newline at end of file
diff --git a/amanuensis/server/session/session.editor.jinja b/amanuensis/server/session/session.editor.jinja
index 0e10d5a..031deb9 100644
--- a/amanuensis/server/session/session.editor.jinja
+++ b/amanuensis/server/session/session.editor.jinja
@@ -34,7 +34,7 @@
 <body>
 	<div id="wrapper">
 		<div id="editor-left" class="column">
-			<div class="contentblock">
+			<section>
 				{# Thin header bar #}
 				<div id="editor-header">
 					{# Header always includes backlink to lexicon #}
@@ -103,16 +103,16 @@
 {#					#}{{ article.contents }}{#
 				#}</textarea>
 				{% endif %}
-			</div>
+			</section>
 		</div>
 		<div id="editor-right" class="column">
-			<div id="preview" class="contentblock">
+			<section id="preview">
 				<p>This editor requires Javascript to function.</p>
 			</div>
-			<div id="preview-citations" class="contentblock">
+			<section id="preview-citations">
 				<p>&nbsp;</p>
 			</div>
-			<div id="preview-control" class="contentblock">
+			<section id="preview-control">
 				<p>&nbsp;</p>
 			</div>
 		</div>
