diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9c86afb..ef37d38 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -103,6 +103,11 @@ mypy:
   script:
     - mypy .
 
+curlylint:
+  <<: *python_test_template
+  script:
+    - curlylint .
+
 prettier:
   <<: *node_test_template
   script:
diff --git a/justfile b/justfile
index 545e0a2..15f46ac 100644
--- a/justfile
+++ b/justfile
@@ -37,6 +37,7 @@ lint_python:
   isort --check .
   flake8
   mypy . --show-error-codes
+  curlylint .
 
 @lint_node:
   npm run lint
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..184721f
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,15 @@
+[tool.curlylint]
+include = '/(website|templates)/.*\.html'
+exclude = '''
+(
+    navbar\.html
+  | referrallink_snippet_link\.html
+  | onlineaccount_snippet_link\.html
+  | base\.html
+  | 500\.html
+)
+'''
+
+[tool.curlylint.rules]
+indent = 2
+html_has_lang = 'en-GB'
diff --git a/requirements/dev.in b/requirements/dev.in
index a23d30e..3fad42e 100644
--- a/requirements/dev.in
+++ b/requirements/dev.in
@@ -10,3 +10,4 @@ django-browser-reload
 django-debug-toolbar
 types-requests
 mypy
+curlylint
diff --git a/requirements/dev.txt b/requirements/dev.txt
index e54f2b0..d8a83b5 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -7,13 +7,15 @@
 anyascii==0.3.1           # via -r requirements/base.txt, wagtail
 asgiref==3.5.2            # via -r requirements/base.txt, django
 async-timeout==4.0.2      # via -r requirements/base.txt, redis
+attrs==22.1.0             # via curlylint
 beautifulsoup4==4.9.3     # via -r requirements/base.txt, wagtail
 black==22.6.0             # via -r requirements/dev.in
 brotli==1.0.9             # via -r requirements/base.txt, whitenoise
 build==0.8.0              # via pip-tools
 certifi==2022.6.15        # via -r requirements/base.txt, requests
 charset-normalizer==2.1.0  # via -r requirements/base.txt, requests
-click==8.1.3              # via -r requirements/base.txt, black, pip-tools, rq
+click==8.1.3              # via -r requirements/base.txt, black, curlylint, pip-tools, rq
+curlylint==0.13.1         # via -r requirements/dev.in
 deprecated==1.2.13        # via -r requirements/base.txt, redis
 django==4.0.6             # via -r requirements/base.txt, django-browser-reload, django-debug-toolbar, django-filter, django-htmx, django-modelcluster, django-permissionedforms, django-redis, django-rq, django-taggit, django-treebeard, djangorestframework, wagtail
 django-browser-reload==1.6.0  # via -r requirements/dev.in
@@ -44,7 +46,8 @@ mypy==0.971               # via -r requirements/dev.in
 mypy-extensions==0.4.3    # via black, mypy
 openpyxl==3.0.10          # via -r requirements/base.txt, tablib
 packaging==21.3           # via -r requirements/base.txt, build, redis
-pathspec==0.9.0           # via black
+parsy==1.1.0              # via curlylint
+pathspec==0.9.0           # via black, curlylint
 pep517==0.12.0            # via build
 pillow==9.2.0             # via -r requirements/base.txt, wagtail
 pip-tools==6.8.0          # via -r requirements/dev.in
@@ -63,6 +66,7 @@ soupsieve==2.3.2.post1    # via -r requirements/base.txt, beautifulsoup4
 sqlparse==0.4.2           # via -r requirements/base.txt, django, django-debug-toolbar
 tablib[xls,xlsx]==3.2.1   # via -r requirements/base.txt, wagtail
 telepath==0.2             # via -r requirements/base.txt, wagtail
+toml==0.10.2              # via curlylint
 tomli==2.0.1              # via black, build, mypy, pep517
 types-requests==2.28.5    # via -r requirements/dev.in
 types-urllib3==1.26.17    # via types-requests
diff --git a/templates/404.html b/templates/404.html
index f19ab95..d31e54c 100644
--- a/templates/404.html
+++ b/templates/404.html
@@ -5,7 +5,7 @@
 {% block body_class %}template-404{% endblock %}
 
 {% block content %}
-<h1>Page not found</h1>
+  <h1>Page not found</h1>
 
-<h2>Sorry, this page could not be found.</h2>
+  <h2>Sorry, this page could not be found.</h2>
 {% endblock %}
diff --git a/templates/500.html b/templates/500.html
index 77379e5..65b5416 100644
--- a/templates/500.html
+++ b/templates/500.html
@@ -1,13 +1,12 @@
 <!DOCTYPE html>
-<html lang="en" dir="ltr">
-    <head>
-        <meta charset="utf-8" />
-        <title>Internal server error</title>
-        <meta name="viewport" content="width=device-width, initial-scale=1" />
-    </head>
-    <body>
-        <h1>Internal server error</h1>
-
-        <h2>Sorry, there seems to be an error. Please try again soon.</h2>
-    </body>
+<html lang="en-GB">
+<head>
+<meta charset="utf-8" />
+<title>Internal server error</title>
+<meta name="viewport" content="width=device-width, initial-scale=1" />
+</head>
+<body>
+<h1>Internal server error</h1>
+<h2>Sorry, there seems to be an error. Please try again soon.</h2>
+</body>
 </html>
diff --git a/templates/base.html b/templates/base.html
index 02ecbc4..c8aae3a 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -1,14 +1,14 @@
 {% load static wagtailcore_tags wagtailuserbar navbar_tags footer_tags cache %}
 
 <!DOCTYPE html>
-<html lang="en">
+<html lang="en-GB">
   <head>
     <meta charset="utf-8" />
     <title>
       {% block title %}{% endblock %}
       {% block title_suffix %}
-      {% wagtail_site as current_site %}
-      {% if current_site and current_site.site_name %}:: {{ current_site.site_name }}{% endif %}
+        {% wagtail_site as current_site %}
+        {% if current_site and current_site.site_name %}:: {{ current_site.site_name }}{% endif %}
       {% endblock %}
     </title>
     <meta name="description" content="" />
@@ -25,7 +25,7 @@
     {% wagtailuserbar %}
 
     {% cache 3600 "navbar" %}
-      {% navbar %}
+    {% navbar %}
     {% endcache %}
 
     {% block main %}
@@ -35,10 +35,9 @@
     {% endblock %}
 
     {% cache 3600 "footer" %}
-      {% footer %}
+    {% footer %}
     {% endcache %}
 
-
     <script async defer type="text/javascript" src="{% static 'js/base.js' %}"></script>
     <script async defer type="text/javascript" src="{% static 'contrib/htmx/htmx.min.js' %}"></script>
 
diff --git a/website/blog/templates/blog/blog_collection_list_page.html b/website/blog/templates/blog/blog_collection_list_page.html
index cb82a20..841a414 100644
--- a/website/blog/templates/blog/blog_collection_list_page.html
+++ b/website/blog/templates/blog/blog_collection_list_page.html
@@ -2,18 +2,18 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container">
+    {% for collection in collections %}
+      {% include "common/listing-item.html" with page=collection %}
+    {% endfor %}
   </section>
-{% endif %}
-
-<section class="container">
-  {% for collection in collections %}
-    {% include "common/listing-item.html" with page=collection %}
-  {% endfor %}
-</section>
 
 {% endblock content %}
diff --git a/website/blog/templates/blog/blog_collection_page.html b/website/blog/templates/blog/blog_collection_page.html
index cdf2916..9f439cd 100644
--- a/website/blog/templates/blog/blog_collection_page.html
+++ b/website/blog/templates/blog/blog_collection_page.html
@@ -2,18 +2,18 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container">
+    {% for page in pages %}
+      {% include "common/listing-item.html" %}
+    {% endfor %}
   </section>
-{% endif %}
-
-<section class="container">
-  {% for page in pages %}
-    {% include "common/listing-item.html" %}
-  {% endfor %}
-</section>
 
 {% endblock content %}
diff --git a/website/blog/templates/blog/blog_list_page.html b/website/blog/templates/blog/blog_list_page.html
index 5d34ee5..e30a68b 100644
--- a/website/blog/templates/blog/blog_list_page.html
+++ b/website/blog/templates/blog/blog_list_page.html
@@ -2,26 +2,26 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container">
+    {% for page in child_pages %}
+      {% if not filtering_by_tag %}
+        {% ifchanged %}
+          <time datetime="{{ page.date|date:'c' }}" title='{{ page.date|date:"F Y" }}'>
+            <h3 id="{{ page.date|date:'Y-m' }}" class="date-header">{{ page.date|date:"Y-m" }}</h3>
+          </time>
+        {% endifchanged %}
+      {% endif %}
+
+      {% include "common/listing-item.html" %}
+    {% endfor %}
   </section>
-{% endif %}
-
-<section class="container">
-  {% for page in child_pages %}
-    {% if not filtering_by_tag %}
-      {% ifchanged %}
-        <time datetime="{{ page.date|date:'c' }}" title='{{ page.date|date:"F Y" }}'>
-          <h3 id="{{ page.date|date:'Y-m' }}" class="date-header">{{ page.date|date:"Y-m" }}</h3>
-        </time>
-      {% endifchanged %}
-    {% endif %}
-
-    {% include "common/listing-item.html" %}
-  {% endfor %}
-</section>
 
 {% endblock content %}
diff --git a/website/blog/templates/blog/blog_post_tag_list_page.html b/website/blog/templates/blog/blog_post_tag_list_page.html
index 5a21c0b..0a102be 100644
--- a/website/blog/templates/blog/blog_post_tag_list_page.html
+++ b/website/blog/templates/blog/blog_post_tag_list_page.html
@@ -2,18 +2,18 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container">
+    {% for tag in tags %}
+      {% include "common/listing-item.html" with page=tag %}
+    {% endfor %}
   </section>
-{% endif %}
-
-<section class="container">
-  {% for tag in tags %}
-    {% include "common/listing-item.html" with page=tag %}
-  {% endfor %}
-</section>
 
 {% endblock content %}
diff --git a/website/blog/templates/blog/blog_post_tag_page.html b/website/blog/templates/blog/blog_post_tag_page.html
index cdf2916..9f439cd 100644
--- a/website/blog/templates/blog/blog_post_tag_page.html
+++ b/website/blog/templates/blog/blog_post_tag_page.html
@@ -2,18 +2,18 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container">
+    {% for page in pages %}
+      {% include "common/listing-item.html" %}
+    {% endfor %}
   </section>
-{% endif %}
-
-<section class="container">
-  {% for page in pages %}
-    {% include "common/listing-item.html" %}
-  {% endfor %}
-</section>
 
 {% endblock content %}
diff --git a/website/common/templates/common/content_page.html b/website/common/templates/common/content_page.html
index fa398b9..7d953b4 100644
--- a/website/common/templates/common/content_page.html
+++ b/website/common/templates/common/content_page.html
@@ -4,13 +4,13 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-<section class="container content">
-  {{ page.body_html|safe }}
-</section>
+  <section class="container content">
+    {{ page.body_html|safe }}
+  </section>
 
-{% include "common/shareon.html" %}
+  {% include "common/shareon.html" %}
 
 {% endblock %}
 
diff --git a/website/common/templates/common/listing_page.html b/website/common/templates/common/listing_page.html
index 6ce8a08..032ade4 100644
--- a/website/common/templates/common/listing_page.html
+++ b/website/common/templates/common/listing_page.html
@@ -2,18 +2,18 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container">
+    {% for page in child_pages %}
+      {% include "common/listing-item.html" %}
+    {% endfor %}
   </section>
-{% endif %}
-
-<section class="container">
-  {% for page in child_pages %}
-    {% include "common/listing-item.html" %}
-  {% endfor %}
-</section>
 
 {% endblock content %}
diff --git a/website/common/templates/common/navbar.html b/website/common/templates/common/navbar.html
index 33b311e..576e6b3 100644
--- a/website/common/templates/common/navbar.html
+++ b/website/common/templates/common/navbar.html
@@ -35,5 +35,4 @@
       </a>
     </div>
   </div>
-  </div>
 </nav>
diff --git a/website/common/templates/common/toc-item.html b/website/common/templates/common/toc-item.html
index 0389dd8..1f1c35e 100644
--- a/website/common/templates/common/toc-item.html
+++ b/website/common/templates/common/toc-item.html
@@ -1,10 +1,10 @@
 <li>
   <a href="#{{ toc_item.slug }}">{{ toc_item.title }}</a>
   {% if toc_item.children %}
-  <ul>
-    {% for toc_item in toc_item.children %}
-      {% include "common/toc-item.html" %}
-    {% endfor %}
-  </ul>
+    <ul>
+      {% for toc_item in toc_item.children %}
+        {% include "common/toc-item.html" %}
+      {% endfor %}
+    </ul>
   {% endif %}
 </li>
diff --git a/website/contact/templates/contact/contact_page.html b/website/contact/templates/contact/contact_page.html
index 2e204c2..67202bd 100644
--- a/website/contact/templates/contact/contact_page.html
+++ b/website/contact/templates/contact/contact_page.html
@@ -2,25 +2,24 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-<section class="container content">
-  {{ page.body_html|safe }}
-</section>
+  <section class="container content">
+    {{ page.body_html|safe }}
+  </section>
 
-<section class="container">
-  {% for account in accounts %}
-    <div class="card mt-4" id="{{ account.slug }}">
-      <div class="card-content">
-        <div class="media">
-          <div class="media-content">
-            <p class="title is-4"><a href="{{ account.url }}">{{ account.name }}</a></p>
-            <p class="subtitle is-6">{{ account.username }}</p>
+  <section class="container">
+    {% for account in accounts %}
+      <div class="card mt-4" id="{{ account.slug }}">
+        <div class="card-content">
+          <div class="media">
+            <div class="media-content">
+              <p class="title is-4"><a href="{{ account.url }}">{{ account.name }}</a></p>
+              <p class="subtitle is-6">{{ account.username }}</p>
+            </div>
           </div>
         </div>
       </div>
-    </div>
-  {% endfor %}
-</section>
-
+    {% endfor %}
+  </section>
 {% endblock %}
diff --git a/website/home/templates/home/home_page.html b/website/home/templates/home/home_page.html
index cddaae2..34bb1be 100644
--- a/website/home/templates/home/home_page.html
+++ b/website/home/templates/home/home_page.html
@@ -3,16 +3,16 @@
 {% load wagtailcore_tags wagtailimages_tags %}
 
 {% block main %}
-<main {% if page.image %}style="background-image: url({% image_url page.image 'width-1200' %})"{% endif %}>
-  <div class="heading-wrapper">
-    <h1>{{ page.heading }}</h1>
-    <input id="search-input" class="input" type="text" placeholder="Search">
-  </div>
-
-  {% if latest_blog_post %}
-    <div class="box latest">
-      <strong>Latest Post</strong>: <a href="{% pageurl latest_blog_post %}">{{ latest_blog_post.title }}</a> &rarr;
+  <main {% if page.image %}style="background-image: url({% image_url page.image 'width-1200' %})"{% endif %}>
+    <div class="heading-wrapper">
+      <h1>{{ page.heading }}</h1>
+      <input id="search-input" class="input" type="text" placeholder="Search">
     </div>
-  {% endif %}
-</main>
+
+    {% if latest_blog_post %}
+      <div class="box latest">
+        <strong>Latest Post</strong>: <a href="{% pageurl latest_blog_post %}">{{ latest_blog_post.title }}</a> &rarr;
+      </div>
+    {% endif %}
+  </main>
 {% endblock %}
diff --git a/website/search/templates/search/search_page.html b/website/search/templates/search/search_page.html
index 965a645..c93072f 100644
--- a/website/search/templates/search/search_page.html
+++ b/website/search/templates/search/search_page.html
@@ -4,48 +4,48 @@
 
 {% block content %}
 
-{% include "common/hero.html" %}
+  {% include "common/hero.html" %}
 
-{% if page.body_html %}
-  <section class="container content">
-    {{ page.body_html|safe }}
+  {% if page.body_html %}
+    <section class="container content">
+      {{ page.body_html|safe }}
+    </section>
+  {% endif %}
+
+  <section class="container search-controls">
+    <div class="field">
+      <p class="control has-icons-left has-icons-right">
+        <input
+          type="search"
+          class="input"
+          name="q"
+          placeholder="Search"
+          hx-get="{{ search_url }}"
+          hx-trigger="keyup changed delay:300ms, search{% if search_query %}, load{% endif %}"
+          hx-target="#search-results"
+          autocomplete="off"
+          value="{{ search_query }}"
+          hx-indicator="#search-indicator"
+        >
+        <span class="icon is-small is-left">
+          <i class="fas fa-search"></i>
+        </span>
+        <span class="icon is-small is-right htmx-indicator" id="search-indicator">
+          <i class="fas fa-circle-notch"></i>
+        </span>
+      </p>
+    </div>
   </section>
-{% endif %}
 
-<section class="container search-controls">
-  <div class="field">
-    <p class="control has-icons-left has-icons-right">
-      <input
-        type="search"
-        class="input"
-        name="q"
-        placeholder="Search"
-        hx-get="{{ search_url }}"
-        hx-trigger="keyup changed delay:300ms, search{% if search_query %}, load{% endif %}"
-        hx-target="#search-results"
-        autocomplete="off"
-        value="{{ search_query }}"
-        hx-indicator="#search-indicator"
-      >
-      <span class="icon is-small is-left">
-        <i class="fas fa-search"></i>
-      </span>
-      <span class="icon is-small is-right htmx-indicator" id="search-indicator">
-        <i class="fas fa-circle-notch"></i>
-      </span>
-    </p>
-  </div>
-</section>
+  <section class="container" id="search-results-container">
+    <p id="result-count"></p>
 
-<section class="container" id="search-results-container">
-  <p id="result-count"></p>
-
-  <div id="search-results">
-    {% if not search_query %}
-      {% include "search/enter-search-term.html" %}
-    {% endif %}
-  </div>
-</section>
+    <div id="search-results">
+      {% if not search_query %}
+        {% include "search/enter-search-term.html" %}
+      {% endif %}
+    </div>
+  </section>
 
 {% endblock %}