diff --git a/commentaries/templates/commentaries/request_arxiv_preprint.html b/commentaries/templates/commentaries/request_arxiv_preprint.html
index 00b5c49b388c3f22484aacd2c0759d1fdbf35b97..5039bdb9845a13d07aca5503dba6f7a5708a7e19 100644
--- a/commentaries/templates/commentaries/request_arxiv_preprint.html
+++ b/commentaries/templates/commentaries/request_arxiv_preprint.html
@@ -7,7 +7,7 @@
 {% block content %}
 
 <div class="row">
-    <div class="col-12">
+    <div class="col">
         <div class="card card-grey">
             <div class="card-body">
               <h1 class="card-title">Request Activation of a Commentary Page</h1>
@@ -17,8 +17,8 @@
     </div>
 </div>
 
-<div class="row">
-    <div class="col-md-8 offset-md-2">
+<div class="row justify-content-center">
+    <div class="col-md-10 col-lg-8">
         <form action="{% url 'commentaries:prefill_using_arxiv_identifier' %}" method="post">
           {% csrf_token %}
           {{ query_form|bootstrap }}
@@ -27,9 +27,8 @@
     </div>
 </div>
 
-{# <hr>#}
-<div class="row">
-    <div class="col-md-8 offset-md-2">
+<div class="row justify-content-center">
+    <div class="col-md-10 col-lg-8">
         <form id="requestForm" action="{% url 'commentaries:request_arxiv_preprint' %}" method="post">
             {% csrf_token %}
             {{ form|bootstrap }}
diff --git a/commentaries/templates/commentaries/request_commentary_old.html b/commentaries/templates/commentaries/request_commentary_old.html
deleted file mode 100644
index e5c38d7f6b93bf7a5ce8a41d050776222d0a2d35..0000000000000000000000000000000000000000
--- a/commentaries/templates/commentaries/request_commentary_old.html
+++ /dev/null
@@ -1,56 +0,0 @@
-{% extends 'scipost/base.html' %}
-
-{% load bootstrap %}
-
-{% load scipost_extras %}
-
-{% block pagetitle %}: request Commentary{% endblock pagetitle %}
-
-{% block content %}
-
-<div class="row">
-    <div class="col-12">
-        <div class="panel">
-            <h1>Request Activation of a Commentary Page:</h1>
-        </div>
-    </div>
-</div>
-<div class="row">
-    <div class="col-md-6 offset-md-3">
-    {% if errormessage %}
-        <h3 style="color: red;">Error: {{ errormessage }}</h3>
-        {% if existing_commentary %}
-            <ul>{% include 'commentaries/_commentary_card_content.html' with object=existing_commentary %}</ul>
-        {% endif %}
-        <br/>
-    {% endif %}
-
-  <div id="DOIprefill">
-    <h3><em>For published papers, you can prefill the form (except for domain, subject area and abstract) using the DOI:</em></h3>
-    <p><em>(give the DOI as 10.[4 to 9 digits]/[string], without prefix, as per the placeholder)</em></p>
-    <form action="{% url 'commentaries:prefill_using_DOI' %}" method="post">
-      {% csrf_token %}
-      {{ doiform|bootstrap }}
-      <input class="btn btn-secondary" type="submit" value="Query DOI"/>
-    </form>
-  </div>
-  <div id="arXivprefill">
-    <h3><em>For preprints, you can prefill the form using the arXiv identifier:</em></h3>
-    <p><em>(give the identifier without prefix, as per the placeholder)</em></p>
-    <form action="{% url 'commentaries:prefill_using_identifier' %}" method="post">
-      {% csrf_token %}
-      {{ identifierform|bootstrap }}
-      <input class="btn btn-secondary" type="submit" value="Query arXiv"/>
-    </form>
-  </div>
-  <br/>
-  <form id="requestForm" action="{% url 'commentaries:request_commentary' %}" method="post">
-    {% csrf_token %}
-      {{ request_commentary_form|bootstrap }}
-    <input class="btn btn-primary" type="submit" value="Submit"/>
-  </form>
-
-    </div>
-</div>
-
-{% endblock content %}
diff --git a/commentaries/templates/commentaries/request_published_article.html b/commentaries/templates/commentaries/request_published_article.html
index a22a197acecb3b5905c0b0c17dc03033ea086f20..5ae3be2a1aac95aa3b3e30d59be8f242784b348b 100644
--- a/commentaries/templates/commentaries/request_published_article.html
+++ b/commentaries/templates/commentaries/request_published_article.html
@@ -18,8 +18,8 @@
     </div>
 </div>
 
-<div class="row">
-    <div class='col-md-8 offset-md-2'>
+<div class="row justify-content-center">
+    <div class='col-md-10 col-lg-8'>
         <form action="{% url 'commentaries:prefill_using_DOI' %}" method="post">
           {% csrf_token %}
           {{ query_form|bootstrap }}
@@ -28,8 +28,8 @@
     </div>
 </div>
 
-<div class="row">
-    <div class='col-md-8 offset-md-2'>
+<div class="row justify-content-center">
+    <div class='col-md-10 col-lg-8'>
         <form id="requestForm" action="{% url 'commentaries:request_published_article' %}" method="post">
             {% csrf_token %}
             {{ form|bootstrap }}
diff --git a/journals/templates/journals/validate_publication.html b/journals/templates/journals/validate_publication.html
index e2fd2cd90b373a7ca0e1a2ec5c48a5e52d452c4d..db78a13e090435434f2826e8dee528feed773071 100644
--- a/journals/templates/journals/validate_publication.html
+++ b/journals/templates/journals/validate_publication.html
@@ -12,8 +12,8 @@
     </div>
 </div>
 
-<div class="row">
-    <div class="col-lg-10 offset-lg-1">
+<div class="row justify-content-center">
+    <div class="col-lg-10">
         {% if errormessage %}
             <h2 style="color: red;">{{ errormessage }}</h2>
         {% endif %}
diff --git a/partners/templates/partners/_prospective_partner_card.html b/partners/templates/partners/_prospective_partner_card.html
index 823372e452ef7449439833c2c66a69cfee184251..28f587665c6f72da23ad1600889cd8ff2c17065e 100644
--- a/partners/templates/partners/_prospective_partner_card.html
+++ b/partners/templates/partners/_prospective_partner_card.html
@@ -44,7 +44,7 @@
   </div>
 
   <div class="row">
-    <div class="col-md-6 offset-md-1">
+    <div class="col-md-6 ml-auto">
       <h3>Events</h3>
       <ul>
 	{% for event in pp.prospectivepartnerevent_set.all %}
diff --git a/partners/templates/partners/activate_account.html b/partners/templates/partners/activate_account.html
index 0e3aef12f1e53ddb919c6a2fc5f06620e70f6f36..1eb07a601fa8562cd259ddbf31f9e1a783f94c5d 100644
--- a/partners/templates/partners/activate_account.html
+++ b/partners/templates/partners/activate_account.html
@@ -1,28 +1,24 @@
 {% extends 'scipost/base.html' %}
 
+{% load bootstrap %}
 
 {% block pagetitle %}{{block.super}} Activate Account{% endblock pagetitle %}
 
-{% load bootstrap %}
-
 {% block content %}
 
-<div class="row">
-    <div class="col-12">
-        <h1 class="highlight">Activate Account</h1>
-    </div>
-    <div class="col-md-8 offset-md-2">
+<h1 class="highlight">Activate Account</h1>
+<div class="row justify-content-center">
+    <div class="col-md-8">
         <h2>{{contact.get_title_display}} {{contact.user.first_name}} {{contact.user.last_name}}</h2>
         <h3>{{contact.user.email}}</h3>
     </div>
 </div>
 
-<div class="row">
-    <div class="col-md-8 offset-md-2 mb-5">
+<div class="row justify-content-center">
+    <div class="col-md-8 mb-5">
       <form method="post">
         {% csrf_token %}
         {{ form|bootstrap }}
-
         <input class="btn btn-primary" type="submit" value="Activate"/>
       </form>
     </div>
diff --git a/partners/templates/partners/membership_request.html b/partners/templates/partners/membership_request.html
index 46675520696142b6d376ae5c7679e5c73072de8e..b06175bb734458c13441a5a4aab9ea1ecde45dd2 100644
--- a/partners/templates/partners/membership_request.html
+++ b/partners/templates/partners/membership_request.html
@@ -2,7 +2,6 @@
 
 {% block pagetitle %}: Supporting Partners Board: Membership request{% endblock pagetitle %}
 
-{% load staticfiles %}
 {% load bootstrap %}
 {% block content %}
 
@@ -28,21 +27,14 @@ $(document).ready(function(){
 </script>
 
 
-<div class="row">
-    <div class="col-lg-10 offset-lg-1">
+<div class="row justify-content-center">
+    <div class="col-lg-10">
       <h1 class="highlight">Supporting Partners Board: Membership Request</h1>
       <p>You can hereby request further details on the process to become one of our Supporting Partners.</p>
       <p>Filling in this form does not yet constitute a binding agreement.</p>
       <p>It simply expresses your interest in considering joining our Supporting Partners Board.</p>
       <p>After filling this form, SciPost Administration will contact you with more details on Partnership.</p>
       <p><em>Note: you will automatically be considered as the contact person for this Partner.</em></p>
-    </div>
-</div>
-
-
-<div class="row">
-    <div class="col-lg-10 offset-lg-1">
-
 
       {% if errormessage %}
           <p class="text-danger">{{ errormessage }}</p>
diff --git a/scipost/forms.py b/scipost/forms.py
index ba8274e92c76cd6d68f92a9543551d88c3c8fab7..ef56c9cf1c29ff7832d30553c6bb9139206f18a8 100644
--- a/scipost/forms.py
+++ b/scipost/forms.py
@@ -398,8 +398,11 @@ class UnavailabilityPeriodForm(forms.ModelForm):
 
     def clean_end(self):
         now = timezone.now()
-        start = self.cleaned_data['start']
-        end = self.cleaned_data['end']
+        start = self.cleaned_data.get('start')
+        end = self.cleaned_data.get('end')
+        if not start or not end:
+            return end
+
         if start > end:
             self.add_error('end', 'The start date you have entered is later than the end date.')
 
diff --git a/scipost/templates/scipost/about.html b/scipost/templates/scipost/about.html
index b4a1fba125f328492168844f124c3b0400ecd0a9..eebe1181be5753a28268a1b63b6488f6f280ab0d 100644
--- a/scipost/templates/scipost/about.html
+++ b/scipost/templates/scipost/about.html
@@ -72,8 +72,8 @@
       <h2 class="highlight">The SciPost Team</h2>
     </div>
 </div>
-<div class="row">
-    <div class="col-md-3 offset-md-1">
+<div class="row justify-content-center">
+    <div class="col-md-4 col-lg-3">
       <h3><a href="{% url 'scipost:foundation' %}">The SciPost Foundation</a></h3>
       <ul>
     	<li>Chairman: Prof. <a href="http://jscaux.org" target="_blank">J.-S. Caux</a></li>
@@ -81,7 +81,7 @@
     	<li>Treasurer: Dr J. van Wezel</li>
       </ul>
     </div>
-    <div class="col-md-6">
+    <div class="col-md-7 col-lg-6">
       <h3>Code Development and Server Maintenance</h3>
       <ul>
     	<li>Lead programmer: J.-S. Caux</li>
@@ -92,27 +92,27 @@
 
 <hr>
 <div class="row">
-  <div class="col-12">
+  <div class="col">
       <h2 class="highlight" id="advisory_board">Advisory Board</h2>
   </div>
 </div>
 
-<div class="row">
-    <div class="col-md-3 offset-md-1">
+<div class="row justify-content-center">
+    <div class="col-lg-3 col-md-4">
       <ul>
 	<li>Prof. <a target="_blank" href="http://www.nikhef.nl/~h02/">J. J. Engelen</a><br/>(U. van Amsterdam)</li>
 	<li>Prof. <a target="_blank" href="https://www.asc.ox.ac.uk/person/18">P. Fendley</a><br/>(Oxford; <a href="https://www.asc.ox.ac.uk/all-souls-college-oxford">All Souls College</a>)</li>
 	<li>Prof. <a target="_blank" href="http://www.ru.nl/highenergyphysics/ehep/persons/sijbrand_de_jong/">S. J. de Jong</a><br/>(Radboud Univ. Nijmegen,<br/>President CERN Council)</li>
       </ul>
     </div>
-    <div class="col-md-3">
+    <div class="col-lg-3 col-md-4">
       <ul>
 	<li>Prof. <a target="_blank" href="http://www.ens-lyon.fr/PHYSIQUE/presentation/annuaire/maillet-jean-michel">J. M. Maillet</a><br/>(ENS Lyon)</li>
 	<li>Prof. <a target="_blank" href="http://www.ru.nl/ssi/members/theo_rasing/">T. Rasing</a><br/>(Radboud Univ. Nijmegen)</li>
 	<li>Prof. <a target="_blank" href="http://atomchip.org/general-information/people/schmiedmayer/">J. Schmiedmayer</a><br/>(TU Vienna)</li>
       </ul>
     </div>
-    <div class="col-md-3">
+    <div class="col-lg-3 col-md-4">
       <ul>
 	<li>Prof. <a target="_blank" href="http://www.professoren.tum.de/en/spohn-herbert/">H. Spohn</a><br/>(TU Munich)</li>
 	<li>Prof. <a target="_blank" href="http://www.comp.phys.ethz.ch/people/troyer.html">M. Troyer</a><br/>(ETH Zurich)</li>
diff --git a/scipost/templates/scipost/call.html b/scipost/templates/scipost/call.html
index 2da3051c915782e9a72ae95c5c7374c936af6b32..95a77b39b83f4836ef6984c91852d067536fad60 100644
--- a/scipost/templates/scipost/call.html
+++ b/scipost/templates/scipost/call.html
@@ -7,12 +7,12 @@
 {% block content %}
 
 <div class="row">
-    <div class="col-12">
+    <div class="col">
       <h1 class="highlight"><a href="{% url 'scipost:about' %}">A call for openness</a></h1>
     </div>
 </div>
-<div class="row">
-    <div class="col-md-10 offset-md-1">
+<div class="row justify-content-center">
+    <div class="col-lg-10">
       <p>
 	Scientific publishing is currently making the news headlines.
 	With the recent <a href="http://english.eu2016.nl/documents/reports/2016/04/04/amsterdam-call-for-action-on-open-science">Amsterdam call for action on open science</a>
diff --git a/scipost/templates/scipost/change_password.html b/scipost/templates/scipost/change_password.html
index ffac2c40459b6a3d8c61fa8ddc8f8d6f517494aa..dd5f72df1f9d3e4d544cba001cfb9f2f1c74a3be 100644
--- a/scipost/templates/scipost/change_password.html
+++ b/scipost/templates/scipost/change_password.html
@@ -1,13 +1,18 @@
-{% extends 'scipost/base.html' %}
+{% extends 'scipost/_personal_page_base.html' %}
 
 {% load bootstrap %}
 
 {% block pagetitle %}: change password{% endblock pagetitle %}
 
+{% block breadcrumb_items %}
+    {{block.super}}
+    <span class="breadcrumb-item">Change password</span>
+{% endblock %}
+
 {% block content %}
 
-<div class="row">
-    <div class="col-lg-8 offset-lg-2">
+<div class="row justify-content-center">
+    <div class="col-lg-8">
         <h1 class="highlight">Change your SciPost password</h1>
 
         <form action="{% url 'scipost:change_password' %}" method="post">
diff --git a/scipost/templates/scipost/email_particular.html b/scipost/templates/scipost/email_particular.html
index 35ca4b7b650b540f3f54d44c210faf57119a8f6f..b9a3037ce57b1c0347fdc6392d514cf3ed2891b4 100644
--- a/scipost/templates/scipost/email_particular.html
+++ b/scipost/templates/scipost/email_particular.html
@@ -13,14 +13,16 @@
 {% block content %}
 
 <div class="row">
-    <div class="col-12">
+    <div class="col">
         <h1 class="highlight">Email a particular</h1>
     </div>
-    <div class="col-md-8 offset-md-2">
+</div>
+<div class="row justify-content-center">
+    <div class="col-md-8">
         <form action="{% url 'scipost:email_particular' %}" method="post">
             {% csrf_token %}
             {{ form|bootstrap:'0,12' }}
-            <input type="submit" class="btn btn-secondary" value="Send email"/>
+            <input type="submit" class="btn btn-primary" value="Send email"/>
         </form>
 
     </div>
diff --git a/scipost/templates/scipost/personal_page.html b/scipost/templates/scipost/personal_page.html
index d5be4918ea246b3b9aaeada4b0f81ee90525d9bb..56cafa2516711eb7fae5d3fb84c801d245636308 100644
--- a/scipost/templates/scipost/personal_page.html
+++ b/scipost/templates/scipost/personal_page.html
@@ -153,8 +153,8 @@
                     </div>
                 </div>
             </div>
-            <div class="row">
-                <div class="col-md-4 offset-md-1">
+            <div class="row justify-content-center">
+                <div class="col-md-4 mr-md-5">
                     <p>To help with the editorial workflow, you can inform us of any periods during which you are unavailable. We will do our best to respect these.</p>
                     <h3 class="mb-3">Mark a period as unavailable:</h3>
                     <form action="{% url 'scipost:mark_unavailable_period' %}" method="post">
@@ -163,7 +163,7 @@
                     	<input class="btn btn-secondary" type="submit" value="Submit" />
                     </form>
                 </div>
-                <div class="col-md-4 offset-md-1">
+                <div class="col-md-4 ml-md-5">
                     {% if unavailabilities %}
                         <h3>Your unavailability periods in our records</h3>
                         <p class="text-muted">(YYYY-DD-MM)</p>
diff --git a/scipost/templates/scipost/reset_password.html b/scipost/templates/scipost/reset_password.html
index e8169dba2c0608cf7b3b4d23b8c83c65d12f15f8..48dad3becede7037661443ccf8a70821619269c4 100644
--- a/scipost/templates/scipost/reset_password.html
+++ b/scipost/templates/scipost/reset_password.html
@@ -7,9 +7,9 @@
 {% block content %}
 
 
-<div class="row">
-    <div class="col-md-4 offset-md-4">
-          <h3>Reset password request form</h3>
+<div class="row justify-content-center">
+    <div class="col-md-4">
+          <h2>Reset password request form</h2>
           <form method="post">
             {% csrf_token %}
             {{ form|bootstrap }}
diff --git a/scipost/templates/scipost/reset_password_confirm.html b/scipost/templates/scipost/reset_password_confirm.html
index 60afebc99f0f143ac49d577665f4475f7e3a6cb2..fe4d5ba196d01f9564082bc223b181a06d1dd59d 100644
--- a/scipost/templates/scipost/reset_password_confirm.html
+++ b/scipost/templates/scipost/reset_password_confirm.html
@@ -6,8 +6,8 @@
 
 {% block content %}
 
-<div class="row">
-    <div class="col-md-6 offset-md-3">
+<div class="row justify-content-center">
+    <div class="col-md-8 col-lg-6">
     {% if validlink %}
         <form method="post">
             {% csrf_token %}
diff --git a/scipost/templates/scipost/unavailability_period_form.html b/scipost/templates/scipost/unavailability_period_form.html
index fc4b11d94fad505d3e50293f9104bd09a166ad68..c014e4cea8bc1fa587dabe090ba4afd366c4283b 100644
--- a/scipost/templates/scipost/unavailability_period_form.html
+++ b/scipost/templates/scipost/unavailability_period_form.html
@@ -11,8 +11,8 @@
 
 {% block content %}
 
-<div class="row">
-    <div class="col-lg-8 offset-lg-2">
+<div class="row justify-content-center">
+    <div class="col-lg-8">
         <h1 class="highlight">Mark a period as unavailable</h1>
 
         <form method="post">
diff --git a/scipost/templates/scipost/update_personal_data.html b/scipost/templates/scipost/update_personal_data.html
index c78cffd259ee0119827e4d310ae2760db81812f1..ab693489e3a48571ac07aba497bc6e9053c71445 100644
--- a/scipost/templates/scipost/update_personal_data.html
+++ b/scipost/templates/scipost/update_personal_data.html
@@ -1,9 +1,14 @@
-{% extends 'scipost/base.html' %}
+{% extends 'scipost/_personal_page_base.html' %}
 
 {% block pagetitle %}: update personal data{% endblock pagetitle %}
 
 {% load bootstrap %}
 
+{% block breadcrumb_items %}
+    {{block.super}}
+    <span class="breadcrumb-item">Update personal data</span>
+{% endblock %}
+
 {% block content %}
 
 {% if cont_form %}
@@ -86,8 +91,8 @@
 {% endif %}
 
 
-<div class="row">
-    <div class="col-lg-10 offset-lg-1">
+<div class="row justify-content-center">
+    <div class="col-lg-10">
         <h1 class="highlight">Update your personal data</h1>
         <form action="{% url 'scipost:update_personal_data' %}" method="post">
             {% csrf_token %}
@@ -95,7 +100,7 @@
             {% if cont_form %}
             	{{cont_form|bootstrap}}
             {% endif %}
-            <input type="submit" class="btn btn-secondary" value="Update" />
+            <input type="submit" class="btn btn-primary" value="Update" />
         </form>
     </div>
 </div>
diff --git a/theses/templates/theses/request_thesislink.html b/theses/templates/theses/request_thesislink.html
index c2274f0d3db222d7b32ded59de8da1fcbf9e6178..7433b1e37b1fb26f44b965ec6e653723cc911a83 100644
--- a/theses/templates/theses/request_thesislink.html
+++ b/theses/templates/theses/request_thesislink.html
@@ -12,8 +12,8 @@
     </div>
 </div>
 
-<div class="row">
-    <div class="col-md-8 offset-md-2">
+<div class="row justify-content-center">
+    <div class="col-md-10 col-lg-8">
       <form action="{% url 'theses:request_thesislink' %}" method="post">
         {% csrf_token %}
         <table>
diff --git a/virtualmeetings/templates/virtualmeetings/VGM_detail.html b/virtualmeetings/templates/virtualmeetings/VGM_detail.html
index c6c699dc155ea9de57815c7c8d78ee0fd411183d..ad312caa0decfad16d6e860d2ba61f1bfa866ef7 100644
--- a/virtualmeetings/templates/virtualmeetings/VGM_detail.html
+++ b/virtualmeetings/templates/virtualmeetings/VGM_detail.html
@@ -242,7 +242,7 @@
 {% for key, val in motion_categories_dict.items %}
     <div class="row">
         <div class="col-12"><h2>{{ val }}:</h2></div>
-        <div class="col-md-11 offset-md-1">
+        <div class="col-md-11 ml-auto">
             <ul>
             {% for motion in VGM.motion_set.all %}
                 {% if motion.category == key %}