diff --git a/application/views/components/manage_appointment_modal.php b/application/views/components/manage_appointment_modal.php
index d9d340e6..29bf91e7 100644
--- a/application/views/components/manage_appointment_modal.php
+++ b/application/views/components/manage_appointment_modal.php
@@ -164,12 +164,12 @@
                             <?= lang('customer_details_title') ?>
                             <button id="new-customer" class="btn btn-outline-secondary btn-sm" type="button"
                                     data-tippy-content="<?= lang('clear_fields_add_existing_customer_hint') ?>">
-                                <i class="fas fa-plus-square mr-2"></i>
+                                <i class="fas fa-plus-square me-2"></i>
                                 <?= lang('new') ?>
                             </button>
                             <button id="select-customer" class="btn btn-outline-secondary btn-sm" type="button"
                                     data-tippy-content="<?= lang('pick_existing_customer_hint') ?>">
-                                <i class="fas fa-hand-pointer mr-2"></i>
+                                <i class="fas fa-hand-pointer me-2"></i>
                                 <span>
                                     <?= lang('select') ?>
                                 </span>
@@ -259,7 +259,7 @@
                     <?= lang('cancel') ?>
                 </button>
                 <button id="save-appointment" class="btn btn-primary">
-                    <i class="fas fa-check-square mr-2"></i>
+                    <i class="fas fa-check-square me-2"></i>
                     <?= lang('save') ?>
                 </button>
             </div>
diff --git a/application/views/components/manage_unavailable_modal.php b/application/views/components/manage_unavailable_modal.php
index ff380b01..f22ced27 100644
--- a/application/views/components/manage_unavailable_modal.php
+++ b/application/views/components/manage_unavailable_modal.php
@@ -75,7 +75,7 @@
                     <?= lang('cancel') ?>
                 </button>
                 <button id="save-unavailable" class="btn btn-primary">
-                    <i class="fas fa-check-square mr-2"></i>
+                    <i class="fas fa-check-square me-2"></i>
                     <?= lang('save') ?>
                 </button>
             </div>
diff --git a/application/views/components/select_google_calendar_modal.php b/application/views/components/select_google_calendar_modal.php
index 38733ebc..808c5518 100644
--- a/application/views/components/select_google_calendar_modal.php
+++ b/application/views/components/select_google_calendar_modal.php
@@ -15,11 +15,11 @@
             </div>
             <div class="modal-footer">
                 <button class="btn btn-outline-secondary" data-dismiss="modal">
-                    <i class="fas fa-ban mr-2"></i>
+                    <i class="fas fa-ban me-2"></i>
                     <?= lang('cancel') ?>
                 </button>
                 <button id="select-calendar" class="btn btn-primary">
-                    <i class="fas fa-check-square mr-2"></i>
+                    <i class="fas fa-check-square me-2"></i>
                     <?= lang('select') ?>
                 </button>
             </div>
diff --git a/application/views/components/working_plan_exceptions_modal.php b/application/views/components/working_plan_exceptions_modal.php
index 2f1fc8a6..2b25984e 100644
--- a/application/views/components/working_plan_exceptions_modal.php
+++ b/application/views/components/working_plan_exceptions_modal.php
@@ -30,7 +30,7 @@
 
                 <div>
                     <button type="button" class="btn btn-primary working-plan-exceptions-add-break">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('add_break') ?>
                     </button>
                 </div>
diff --git a/application/views/layouts/backend/backend_footer.php b/application/views/layouts/backend/backend_footer.php
index 229d7126..b8f0440b 100644
--- a/application/views/layouts/backend/backend_footer.php
+++ b/application/views/layouts/backend/backend_footer.php
@@ -5,7 +5,7 @@
 ?>
 <div id="footer">
     <div id="footer-content" class="col-12 col-sm-8">
-        <img class="mr-1" src="<?= base_url('assets/img/logo-16x16.png') ?>" alt="Easy!Appointments Logo">
+        <img class="me-1" src="<?= base_url('assets/img/logo-16x16.png') ?>" alt="Easy!Appointments Logo">
         <a href="https://easyappointments.org">
             Easy!Appointments
         </a>
@@ -33,7 +33,7 @@
         |
 
         <span id="select-language" class="badge bg-secondary">
-            <i class="fas fa-language mr-2"></i>
+            <i class="fas fa-language me-2"></i>
         	<?= ucfirst(config('language')) ?>
         </span>
 
diff --git a/application/views/layouts/backend/backend_header.php b/application/views/layouts/backend/backend_header.php
index 64db960d..761f285b 100755
--- a/application/views/layouts/backend/backend_header.php
+++ b/application/views/layouts/backend/backend_header.php
@@ -12,7 +12,7 @@
         <small>Open Source Appointment Scheduler</small>
     </div>
 
-    <button type="button" class="navbar-toggler" data-bs-toggle="collapse" data-target="#header-menu">
+    <button type="button" class="navbar-toggler" data-bs-toggle="collapse" data-bs-target="#header-menu">
         <span class="sr-only">Toggle navigation</span>
         <span class="navbar-toggler-icon"></span>
     </button>
@@ -24,7 +24,7 @@
             <li class="nav-item <?= $active . $hidden ?>">
                 <a href="<?= site_url('backend') ?>" class="nav-link"
                    data-tippy-content="<?= lang('manage_appointment_record_hint') ?>">
-                    <i class="fas fa-calendar-alt mr-2"></i>
+                    <i class="fas fa-calendar-alt me-2"></i>
                     <?= lang('calendar') ?>
                 </a>
             </li>
@@ -34,7 +34,7 @@
             <li class="nav-item <?= $active . $hidden ?>">
                 <a href="<?= site_url('backend/customers') ?>" class="nav-link"
                    data-tippy-content="<?= lang('manage_customers_hint') ?>">
-                    <i class="fas fa-user-friends mr-2"></i>
+                    <i class="fas fa-user-friends me-2"></i>
                     <?= lang('customers') ?>
                 </a>
             </li>
@@ -44,7 +44,7 @@
             <li class="nav-item dropdown <?= $active . $hidden ?>">
                 <a class="nav-link dropdown-toggle" href="#" data-bs-toggle="dropdown" 
                    data-tippy-content="<?= lang('manage_services_hint') ?>">
-                    <i class="fas fa-business-time mr-2"></i>
+                    <i class="fas fa-business-time me-2"></i>
                     <?= lang('services') ?>
                 </a>
                 <div class="dropdown-menu dropdown-menu-right">
@@ -62,7 +62,7 @@
             <li class="nav-item dropdown <?= $active . $hidden ?>">
                 <a class="nav-link dropdown-toggle" href="#" data-bs-toggle="dropdown"
                    data-tippy-content="<?= lang('manage_users_hint') ?>">
-                    <i class="fas fa-business-time mr-2"></i>
+                    <i class="fas fa-business-time me-2"></i>
                     <?= lang('users') ?>
                 </a>
                 <div class="dropdown-menu dropdown-menu-right">
@@ -84,7 +84,7 @@
             <li class="nav-item dropdown <?= $active . $hidden ?>">
                 <a class="nav-link dropdown-toggle" href="#" data-bs-toggle="dropdown"
                    data-tippy-content="<?= lang('settings_hint') ?>">
-                    <i class="fas fa-cogs mr-2"></i>
+                    <i class="fas fa-cogs me-2"></i>
                     <?= lang('settings') ?>
                 </a>
                 <div class="dropdown-menu dropdown-menu-right">
diff --git a/application/views/layouts/booking/booking_footer.php b/application/views/layouts/booking/booking_footer.php
index 774afa10..dded36ac 100644
--- a/application/views/layouts/booking/booking_footer.php
+++ b/application/views/layouts/booking/booking_footer.php
@@ -8,12 +8,12 @@
 
         <span class="footer-options">
             <span id="select-language" class="badge bg-secondary">
-                <i class="fas fa-language mr-2"></i>
+                <i class="fas fa-language me-2"></i>
                 <?= ucfirst(config('language')) ?>
             </span>
     
             <a class="backend-link badge bg-primary" href="<?= site_url('backend'); ?>">
-                <i class="fas fa-sign-in-alt mr-2"></i>
+                <i class="fas fa-sign-in-alt me-2"></i>
                 <?= session('user_id') ? lang('backend_section') : lang('login') ?>
             </a>
         </span>
diff --git a/application/views/pages/account/account_login_page.php b/application/views/pages/account/account_login_page.php
index 543b360d..38a58fc4 100644
--- a/application/views/pages/account/account_login_page.php
+++ b/application/views/pages/account/account_login_page.php
@@ -32,7 +32,7 @@
 
     <div class="form-group">
         <button type="submit" id="login" class="btn btn-primary">
-            <i class="fas fa-sign-in-alt mr-2"></i>
+            <i class="fas fa-sign-in-alt me-2"></i>
             <?= lang('login') ?>
         </button>
     </div>
diff --git a/application/views/pages/account/account_logout_page.php b/application/views/pages/account/account_logout_page.php
index bfbc4e22..fd449730 100644
--- a/application/views/pages/account/account_logout_page.php
+++ b/application/views/pages/account/account_logout_page.php
@@ -11,12 +11,12 @@
 <br>
 
 <a href="<?= site_url() ?>" class="btn btn-success btn-large">
-    <i class="fas fa-calendar-alt mr-2"></i>
+    <i class="fas fa-calendar-alt me-2"></i>
     <?= lang('book_appointment_title') ?>
 </a>
 
 <a href="<?= site_url('backend') ?>" class="btn btn-outline-secondary btn-large">
-    <i class="fas fa-wrench mr-2"></i>
+    <i class="fas fa-wrench me-2"></i>
     <?= lang('backend_section') ?>
 </a>
 
diff --git a/application/views/pages/account/account_no_permissions_page.php b/application/views/pages/account/account_no_permissions_page.php
index dcc50f88..2582a967 100644
--- a/application/views/pages/account/account_no_permissions_page.php
+++ b/application/views/pages/account/account_no_permissions_page.php
@@ -10,7 +10,7 @@
 <br>
 
 <a href="<?= site_url('backend') ?>" class="btn btn-success btn-large">
-    <i class="icon-calendar icon-white mr-2"></i>
+    <i class="icon-calendar icon-white me-2"></i>
     <?= lang('backend_calendar') ?>
 </a>
 
diff --git a/application/views/pages/account/account_recovery_page.php b/application/views/pages/account/account_recovery_page.php
index 9911f002..bfea9a4e 100644
--- a/application/views/pages/account/account_recovery_page.php
+++ b/application/views/pages/account/account_recovery_page.php
@@ -23,7 +23,7 @@
     <br>
 
     <button type="submit" id="get-new-password" class="btn btn-primary btn-large">
-        <i class="fas fa-unlock-alt mr-2"></i>
+        <i class="fas fa-unlock-alt me-2"></i>
         <?= lang('regenerate_password') ?>
     </button>
 
diff --git a/application/views/pages/admins/admins_page.php b/application/views/pages/admins/admins_page.php
index e47ab957..81c185f2 100755
--- a/application/views/pages/admins/admins_page.php
+++ b/application/views/pages/admins/admins_page.php
@@ -64,26 +64,26 @@
             <div class="btn-toolbar mb-4">
                 <div class="add-edit-delete-group btn-group">
                     <button id="add-admin" class="btn btn-primary">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('add') ?>
                     </button>
                     <button id="edit-admin" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-edit mr-2"></i>
+                        <i class="fas fa-edit me-2"></i>
                         <?= lang('edit') ?>
                     </button>
                     <button id="delete-admin" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-trash-alt mr-2"></i>
+                        <i class="fas fa-trash-alt me-2"></i>
                         <?= lang('delete') ?>
                     </button>
                 </div>
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-admin" class="btn btn-primary">
-                        <i class="fas fa-check-square mr-2"></i>
+                        <i class="fas fa-check-square me-2"></i>
                         <?= lang('save') ?>
                     </button>
                     <button id="cancel-admin" class="btn btn-outline-secondary">
-                        <i class="fas fa-ban mr-2"></i>
+                        <i class="fas fa-ban me-2"></i>
                         <?= lang('cancel') ?>
                     </button>
                 </div>
diff --git a/application/views/pages/booking/booking_step_1.php b/application/views/pages/booking/booking_step_1.php
index d40b7808..b10623bd 100644
--- a/application/views/pages/booking/booking_step_1.php
+++ b/application/views/pages/booking/booking_step_1.php
@@ -98,7 +98,7 @@
         <button type="button" id="button-next-1" class="btn button-next btn-dark"
                 data-step_index="1">
             <?= lang('next') ?>
-            <i class="fas fa-chevron-right ml-2"></i>
+            <i class="fas fa-chevron-right ms-2"></i>
         </button>
     </div>
 </div>
diff --git a/application/views/pages/booking/booking_step_2.php b/application/views/pages/booking/booking_step_2.php
index 9036e310..05d09345 100644
--- a/application/views/pages/booking/booking_step_2.php
+++ b/application/views/pages/booking/booking_step_2.php
@@ -30,13 +30,13 @@
     <div class="command-buttons">
         <button type="button" id="button-back-2" class="btn button-back btn-outline-secondary"
                 data-step_index="2">
-            <i class="fas fa-chevron-left mr-2"></i>
+            <i class="fas fa-chevron-left me-2"></i>
             <?= lang('back') ?>
         </button>
         <button type="button" id="button-next-2" class="btn button-next btn-dark"
                 data-step_index="2">
             <?= lang('next') ?>
-            <i class="fas fa-chevron-right ml-2"></i>
+            <i class="fas fa-chevron-right ms-2"></i>
         </button>
     </div>
 </div>
diff --git a/application/views/pages/booking/booking_step_3.php b/application/views/pages/booking/booking_step_3.php
index f9ffb22e..46964577 100644
--- a/application/views/pages/booking/booking_step_3.php
+++ b/application/views/pages/booking/booking_step_3.php
@@ -81,7 +81,7 @@
             <label class="form-check-label" for="accept-to-terms-and-conditions">
                 <?= strtr(lang('read_and_agree_to_terms_and_conditions'),
                     [
-                        '{$link}' => '<a href="#" data-bs-toggle="modal" data-target="#terms-and-conditions-modal">',
+                        '{$link}' => '<a href="#" data-bs-toggle="modal" data-bs-target="#terms-and-conditions-modal">',
                         '{/$link}' => '</a>'
                     ])
                 ?>
@@ -95,7 +95,7 @@
             <label class="form-check-label" for="accept-to-privacy-policy">
                 <?= strtr(lang('read_and_agree_to_privacy_policy'),
                     [
-                        '{$link}' => '<a href="#" data-bs-toggle="modal" data-target="#privacy-policy-modal">',
+                        '{$link}' => '<a href="#" data-bs-toggle="modal" data-bs-target="#privacy-policy-modal">',
                         '{/$link}' => '</a>'
                     ])
                 ?>
@@ -106,13 +106,13 @@
     <div class="command-buttons">
         <button type="button" id="button-back-3" class="btn button-back btn-outline-secondary"
                 data-step_index="3">
-            <i class="fas fa-chevron-left mr-2"></i>
+            <i class="fas fa-chevron-left me-2"></i>
             <?= lang('back') ?>
         </button>
         <button type="button" id="button-next-3" class="btn button-next btn-dark"
                 data-step_index="3">
             <?= lang('next') ?>
-            <i class="fas fa-chevron-right ml-2"></i>
+            <i class="fas fa-chevron-right ms-2"></i>
         </button>
     </div>
 </div>
diff --git a/application/views/pages/booking/booking_step_4.php b/application/views/pages/booking/booking_step_4.php
index a0fed155..03788b1d 100644
--- a/application/views/pages/booking/booking_step_4.php
+++ b/application/views/pages/booking/booking_step_4.php
@@ -25,12 +25,12 @@
     <div class="command-buttons">
         <button type="button" id="button-back-4" class="btn button-back btn-outline-secondary"
                 data-step_index="4">
-            <i class="fas fa-chevron-left mr-2"></i>
+            <i class="fas fa-chevron-left me-2"></i>
             <?= lang('back') ?>
         </button>
         <form id="book-appointment-form" style="display:inline-block" method="post">
             <button id="book-appointment-submit" type="button" class="btn btn-success">
-                <i class="fas fa-check-square mr-2"></i>
+                <i class="fas fa-check-square me-2"></i>
                 <?= ! $manage_mode ? lang('confirm') : lang('update') ?>
             </button>
             <input type="hidden" name="csrfToken"/>
diff --git a/application/views/pages/calendar/calendar_page.php b/application/views/pages/calendar/calendar_page.php
index 88460643..3c401980 100755
--- a/application/views/pages/calendar/calendar_page.php
+++ b/application/views/pages/calendar/calendar_page.php
@@ -93,7 +93,7 @@
 
                 <button id="enable-sync" class="btn btn-light" data-bs-toggle="button"
                         data-tippy-content="<?= lang('enable_appointment_sync_hint') ?>">
-                    <i class="fas fa-calendar-alt mr-2"></i>
+                    <i class="fas fa-calendar-alt me-2"></i>
                     <span><?= lang('enable_sync') ?></span>
                 </button>
             <?php endif ?>
@@ -101,7 +101,7 @@
             <?php if ($privileges[PRIV_APPOINTMENTS]['add'] == TRUE): ?>
                 <div class="btn-group">
                     <button class="btn btn-light" id="insert-appointment">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('appointment') ?>
                     </button>
 
@@ -112,12 +112,12 @@
 
                     <div class="dropdown-menu">
                         <a class="dropdown-item" href="#" id="insert-unavailable">
-                            <i class="fas fa-plus-square mr-2"></i>
+                            <i class="fas fa-plus-square me-2"></i>
                             <?= lang('unavailable') ?>
                         </a>
                         <a class="dropdown-item" href="#" id="insert-working-plan-exception"
                             <?= $this->session->userdata('role_slug') !== 'admin' ? 'hidden' : '' ?>>
-                            <i class="fas fa-plus-square mr-2"></i>
+                            <i class="fas fa-plus-square me-2"></i>
                             <?= lang('working_plan_exception') ?>
                         </a>
                     </div>
diff --git a/application/views/pages/customers/customers_page.php b/application/views/pages/customers/customers_page.php
index 343c18ae..cd2de9a5 100755
--- a/application/views/pages/customers/customers_page.php
+++ b/application/views/pages/customers/customers_page.php
@@ -80,21 +80,21 @@
                 <div id="add-edit-delete-group" class="btn-group">
                     <?php if ($privileges[PRIV_CUSTOMERS]['add'] === TRUE): ?>
                         <button id="add-customer" class="btn btn-primary">
-                            <i class="fas fa-plus-square mr-2"></i>
+                            <i class="fas fa-plus-square me-2"></i>
                             <?= lang('add') ?>
                         </button>
                     <?php endif ?>
 
                     <?php if ($privileges[PRIV_CUSTOMERS]['edit'] === TRUE): ?>
                         <button id="edit-customer" class="btn btn-outline-secondary" disabled="disabled">
-                            <i class="fas fa-edit mr-2"></i>
+                            <i class="fas fa-edit me-2"></i>
                             <?= lang('edit') ?>
                         </button>
                     <?php endif ?>
 
                     <?php if ($privileges[PRIV_CUSTOMERS]['delete'] === TRUE): ?>
                         <button id="delete-customer" class="btn btn-outline-secondary" disabled="disabled">
-                            <i class="fas fa-trash-alt mr-2"></i>
+                            <i class="fas fa-trash-alt me-2"></i>
                             <?= lang('delete') ?>
                         </button>
                     <?php endif ?>
@@ -102,11 +102,11 @@
 
                 <div id="save-cancel-group" class="btn-group" style="display:none;">
                     <button id="save-customer" class="btn btn-primary">
-                        <i class="fas fa-check-square mr-2"></i>
+                        <i class="fas fa-check-square me-2"></i>
                         <?= lang('save') ?>
                     </button>
                     <button id="cancel-customer" class="btn btn-outline-secondary">
-                        <i class="fas fa-ban mr-2"></i>
+                        <i class="fas fa-ban me-2"></i>
                         <?= lang('cancel') ?>
                     </button>
                 </div>
diff --git a/application/views/pages/instance/instance_installation_page.php b/application/views/pages/instance/instance_installation_page.php
index 36b49982..985dc505 100755
--- a/application/views/pages/instance/instance_installation_page.php
+++ b/application/views/pages/instance/instance_installation_page.php
@@ -124,7 +124,7 @@
     <br>
 
     <button type="button" id="install" class="btn btn-success btn-large">
-        <i class="icon-white icon-ok mr-2"></i>
+        <i class="icon-white icon-ok me-2"></i>
         Install Easy!Appointments
     </button>
 </div>
diff --git a/application/views/pages/instance/instance_update_page.php b/application/views/pages/instance/instance_update_page.php
index 2cdc926b..aba1bfd3 100644
--- a/application/views/pages/instance/instance_update_page.php
+++ b/application/views/pages/instance/instance_update_page.php
@@ -39,7 +39,7 @@
                         You can now use the latest Easy!Appointments version.
                     </p>
                     <a href="<?= site_url('backend') ?>" class="btn btn-success btn-large">
-                        <i class="fas fa-wrench mr-2"></i>
+                        <i class="fas fa-wrench me-2"></i>
                         <?= lang('backend_section') ?>
                     </a>
                 </div>
@@ -54,7 +54,7 @@
                         Please restore your database backup.
                     </p>
                     <a href="<?= site_url('backend') ?>" class="btn btn-success btn-large">
-                        <i class="fas fa-wrench mr-2"></i>
+                        <i class="fas fa-wrench me-2"></i>
                         <?= lang('backend_section') ?>
                     </a>
 
diff --git a/application/views/pages/providers/providers_page.php b/application/views/pages/providers/providers_page.php
index d1a10e8e..499fdb9c 100755
--- a/application/views/pages/providers/providers_page.php
+++ b/application/views/pages/providers/providers_page.php
@@ -67,29 +67,29 @@
         </div>
 
         <div class="record-details column col-12 col-md-7">
-            <div class="float-md-left mb-4 mr-4">
+            <div class="float-md-left mb-4 me-4">
                 <div class="add-edit-delete-group btn-group">
                     <button id="add-provider" class="btn btn-primary">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('add') ?>
                     </button>
                     <button id="edit-provider" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-edit mr-2"></i>
+                        <i class="fas fa-edit me-2"></i>
                         <?= lang('edit') ?>
                     </button>
                     <button id="delete-provider" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-trash-alt mr-2"></i>
+                        <i class="fas fa-trash-alt me-2"></i>
                         <?= lang('delete') ?>
                     </button>
                 </div>
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-provider" class="btn btn-primary">
-                        <i class="fas fa-check-square mr-2"></i>
+                        <i class="fas fa-check-square me-2"></i>
                         <?= lang('save') ?>
                     </button>
                     <button id="cancel-provider" class="btn btn-outline-secondary">
-                        <i class="fas fa-ban mr-2"></i>
+                        <i class="fas fa-ban me-2"></i>
                         <?= lang('cancel') ?>
                     </button>
                 </div>
@@ -268,7 +268,7 @@
                     <h3><?= lang('working_plan') ?></h3>
                     <button id="reset-working-plan" class="btn btn-primary"
                             data-tippy-content="<?= lang('reset_working_plan') ?>">
-                        <i class="fas fa-redo-alt mr-2"></i>
+                        <i class="fas fa-redo-alt me-2"></i>
                         <?= lang('reset_plan') ?></button>
                     <table class="working-plan table table-striped mt-2">
                         <thead>
@@ -291,7 +291,7 @@
 
                     <div>
                         <button type="button" class="add-break btn btn-primary">
-                            <i class="fas fa-plus-square mr-2"></i>
+                            <i class="fas fa-plus-square me-2"></i>
                             <?= lang('add_break') ?>
                         </button>
                     </div>
@@ -319,7 +319,7 @@
                     </p>
 
                     <div>
-                        <button type="button" class="add-working-plan-exception btn btn-primary mr-2">
+                        <button type="button" class="add-working-plan-exception btn btn-primary me-2">
                             <i class="fas fa-plus-square"></i>
                             <?= lang('add_working_plan_exception') ?>
                         </button>
diff --git a/application/views/pages/secretaries/secretaries_page.php b/application/views/pages/secretaries/secretaries_page.php
index a4a570c3..5470bb3d 100755
--- a/application/views/pages/secretaries/secretaries_page.php
+++ b/application/views/pages/secretaries/secretaries_page.php
@@ -66,26 +66,26 @@
             <div class="btn-toolbar mb-4">
                 <div class="add-edit-delete-group btn-group">
                     <button id="add-secretary" class="btn btn-primary">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('add') ?>
                     </button>
                     <button id="edit-secretary" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-edit mr-2"></i>
+                        <i class="fas fa-edit me-2"></i>
                         <?= lang('edit') ?>
                     </button>
                     <button id="delete-secretary" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-trash-alt mr-2"></i>
+                        <i class="fas fa-trash-alt me-2"></i>
                         <?= lang('delete') ?>
                     </button>
                 </div>
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-secretary" class="btn btn-primary">
-                        <i class="fas fa-check-square mr-2"></i>
+                        <i class="fas fa-check-square me-2"></i>
                         <?= lang('save') ?>
                     </button>
                     <button id="cancel-secretary" class="btn btn-outline-secondary">
-                        <i class="fas fa-ban mr-2"></i>
+                        <i class="fas fa-ban me-2"></i>
                         <?= lang('cancel') ?>
                     </button>
                 </div>
diff --git a/application/views/pages/service_categories/service_categories_page.php b/application/views/pages/service_categories/service_categories_page.php
index 036a483a..ecaa98cc 100755
--- a/application/views/pages/service_categories/service_categories_page.php
+++ b/application/views/pages/service_categories/service_categories_page.php
@@ -63,26 +63,26 @@
             <div class="btn-toolbar mb-4">
                 <div class="add-edit-delete-group btn-group">
                     <button id="add-category" class="btn btn-primary">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('add') ?>
                     </button>
                     <button id="edit-category" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-edit mr-2"></i>
+                        <i class="fas fa-edit me-2"></i>
                         <?= lang('edit') ?>
                     </button>
                     <button id="delete-category" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-trash-alt mr-2"></i>
+                        <i class="fas fa-trash-alt me-2"></i>
                         <?= lang('delete') ?>
                     </button>
                 </div>
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-category" class="btn btn-primary">
-                        <i class="fas fa-check-square mr-2"></i>
+                        <i class="fas fa-check-square me-2"></i>
                         <?= lang('save') ?>
                     </button>
                     <button id="cancel-category" class="btn btn-outline-secondary">
-                        <i class="fas fa-ban mr-2"></i>
+                        <i class="fas fa-ban me-2"></i>
                         <?= lang('cancel') ?>
                     </button>
                 </div>
diff --git a/application/views/pages/services/services_page.php b/application/views/pages/services/services_page.php
index a6c0e8f5..74c96575 100755
--- a/application/views/pages/services/services_page.php
+++ b/application/views/pages/services/services_page.php
@@ -62,26 +62,26 @@
             <div class="btn-toolbar mb-4">
                 <div class="add-edit-delete-group btn-group">
                     <button id="add-service" class="btn btn-primary">
-                        <i class="fas fa-plus-square mr-2"></i>
+                        <i class="fas fa-plus-square me-2"></i>
                         <?= lang('add') ?>
                     </button>
                     <button id="edit-service" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-edit mr-2"></i>
+                        <i class="fas fa-edit me-2"></i>
                         <?= lang('edit') ?>
                     </button>
                     <button id="delete-service" class="btn btn-outline-secondary" disabled="disabled">
-                        <i class="fas fa-trash-alt mr-2"></i>
+                        <i class="fas fa-trash-alt me-2"></i>
                         <?= lang('delete') ?>
                     </button>
                 </div>
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-service" class="btn btn-primary">
-                        <i class="fas fa-check-square mr-2"></i>
+                        <i class="fas fa-check-square me-2"></i>
                         <?= lang('save') ?>
                     </button>
                     <button id="cancel-service" class="btn btn-outline-secondary">
-                        <i class="fas fa-ban mr-2"></i>
+                        <i class="fas fa-ban me-2"></i>
                         <?= lang('cancel') ?>
                     </button>
                 </div>
diff --git a/application/views/pages/settings/business_logic/business_logic_page.php b/application/views/pages/settings/business_logic/business_logic_page.php
index c2b00a43..ef748155 100755
--- a/application/views/pages/settings/business_logic/business_logic_page.php
+++ b/application/views/pages/settings/business_logic/business_logic_page.php
@@ -50,7 +50,7 @@
                     <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['edit'] == TRUE): ?>
                         <button type="button" class="save-settings btn btn-primary btn-sm mb-2"
                                 data-tippy-content="<?= lang('save') ?>">
-                            <i class="fas fa-check-square mr-2"></i>
+                            <i class="fas fa-check-square me-2"></i>
                             <?= lang('save') ?>
                         </button>
                     <?php endif ?>
diff --git a/application/views/pages/settings/client_form/client_form_page.php b/application/views/pages/settings/client_form/client_form_page.php
index 142178ab..0021fbf4 100755
--- a/application/views/pages/settings/client_form/client_form_page.php
+++ b/application/views/pages/settings/client_form/client_form_page.php
@@ -48,7 +48,7 @@
                     <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['edit'] == TRUE): ?>
                         <button type="button" class="save-settings btn btn-primary btn-sm mb-2"
                                 data-tippy-content="<?= lang('save') ?>">
-                            <i class="fas fa-check-square mr-2"></i>
+                            <i class="fas fa-check-square me-2"></i>
                             <?= lang('save') ?>
                         </button>
                     <?php endif ?>
diff --git a/application/views/pages/settings/current_user/current_user_page.php b/application/views/pages/settings/current_user/current_user_page.php
index 5f676c6a..f01f214b 100644
--- a/application/views/pages/settings/current_user/current_user_page.php
+++ b/application/views/pages/settings/current_user/current_user_page.php
@@ -48,7 +48,7 @@
                         <?php if ($privileges[PRIV_USER_SETTINGS]['edit'] == TRUE): ?>
                             <button type="button" class="save-settings btn btn-primary btn-sm mb-2"
                                     data-tippy-content="<?= lang('save') ?>">
-                                <i class="fas fa-check-square mr-2"></i>
+                                <i class="fas fa-check-square me-2"></i>
                                 <?= lang('save') ?>
                             </button>
                         <?php endif ?>
diff --git a/application/views/pages/settings/general/general_page.php b/application/views/pages/settings/general/general_page.php
index 81040a5d..b959f515 100755
--- a/application/views/pages/settings/general/general_page.php
+++ b/application/views/pages/settings/general/general_page.php
@@ -46,7 +46,7 @@
                         <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['edit'] == TRUE): ?>
                             <button type="button" class="save-settings btn btn-primary btn-sm mb-2"
                                     data-tippy-content="<?= lang('save') ?>">
-                                <i class="fas fa-check-square mr-2"></i>
+                                <i class="fas fa-check-square me-2"></i>
                                 <?= lang('save') ?>
                             </button>
                         <?php endif ?>
diff --git a/application/views/pages/settings/legal_contents/legal_contents_page.php b/application/views/pages/settings/legal_contents/legal_contents_page.php
index f507d564..f21d32f9 100755
--- a/application/views/pages/settings/legal_contents/legal_contents_page.php
+++ b/application/views/pages/settings/legal_contents/legal_contents_page.php
@@ -44,7 +44,7 @@
                     <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['edit'] == TRUE): ?>
                         <button type="button" class="save-settings btn btn-primary btn-sm mb-2"
                                 data-tippy-content="<?= lang('save') ?>">
-                            <i class="fas fa-check-square mr-2"></i>
+                            <i class="fas fa-check-square me-2"></i>
                             <?= lang('save') ?>
                         </button>
                     <?php endif ?>
diff --git a/application/views/pages/users/users_page.php b/application/views/pages/users/users_page.php
index 43e2a120..a6e7d701 100755
--- a/application/views/pages/users/users_page.php
+++ b/application/views/pages/users/users_page.php
@@ -112,29 +112,29 @@
                 </div>
 
                 <div class="record-details column col-12 col-md-7">
-                    <div class="float-md-left mb-4 mr-4">
+                    <div class="float-md-left mb-4 me-4">
                         <div class="add-edit-delete-group btn-group">
                             <button id="add-provider" class="btn btn-primary">
-                                <i class="fas fa-plus-square mr-2"></i>
+                                <i class="fas fa-plus-square me-2"></i>
                                 <?= lang('add') ?>
                             </button>
                             <button id="edit-provider" class="btn btn-outline-secondary" disabled="disabled">
-                                <i class="fas fa-edit mr-2"></i>
+                                <i class="fas fa-edit me-2"></i>
                                 <?= lang('edit') ?>
                             </button>
                             <button id="delete-provider" class="btn btn-outline-secondary" disabled="disabled">
-                                <i class="fas fa-trash-alt mr-2"></i>
+                                <i class="fas fa-trash-alt me-2"></i>
                                 <?= lang('delete') ?>
                             </button>
                         </div>
 
                         <div class="save-cancel-group btn-group" style="display:none;">
                             <button id="save-provider" class="btn btn-primary">
-                                <i class="fas fa-check-square mr-2"></i>
+                                <i class="fas fa-check-square me-2"></i>
                                 <?= lang('save') ?>
                             </button>
                             <button id="cancel-provider" class="btn btn-outline-secondary">
-                                <i class="fas fa-ban mr-2"></i>
+                                <i class="fas fa-ban me-2"></i>
                                 <?= lang('cancel') ?>
                             </button>
                         </div>
@@ -313,7 +313,7 @@
                             <h3><?= lang('working_plan') ?></h3>
                             <button id="reset-working-plan" class="btn btn-primary"
                                     data-tippy-content="<?= lang('reset_working_plan') ?>">
-                                <i class="fas fa-redo-alt mr-2"></i>
+                                <i class="fas fa-redo-alt me-2"></i>
                                 <?= lang('reset_plan') ?></button>
                             <table class="working-plan table table-striped mt-2">
                                 <thead>
@@ -336,7 +336,7 @@
 
                             <div>
                                 <button type="button" class="add-break btn btn-primary">
-                                    <i class="fas fa-plus-square mr-2"></i>
+                                    <i class="fas fa-plus-square me-2"></i>
                                     <?= lang('add_break') ?>
                                 </button>
                             </div>
@@ -364,7 +364,7 @@
                             </p>
 
                             <div>
-                                <button type="button" class="add-working-plan-exception btn btn-primary mr-2">
+                                <button type="button" class="add-working-plan-exception btn btn-primary me-2">
                                     <i class="fas fa-plus-square"></i>
                                     <?= lang('add_working_plan_exception') ?>
                                 </button>
@@ -424,26 +424,26 @@
                     <div class="btn-toolbar mb-4">
                         <div class="add-edit-delete-group btn-group">
                             <button id="add-secretary" class="btn btn-primary">
-                                <i class="fas fa-plus-square mr-2"></i>
+                                <i class="fas fa-plus-square me-2"></i>
                                 <?= lang('add') ?>
                             </button>
                             <button id="edit-secretary" class="btn btn-outline-secondary" disabled="disabled">
-                                <i class="fas fa-edit mr-2"></i>
+                                <i class="fas fa-edit me-2"></i>
                                 <?= lang('edit') ?>
                             </button>
                             <button id="delete-secretary" class="btn btn-outline-secondary" disabled="disabled">
-                                <i class="fas fa-trash-alt mr-2"></i>
+                                <i class="fas fa-trash-alt me-2"></i>
                                 <?= lang('delete') ?>
                             </button>
                         </div>
 
                         <div class="save-cancel-group btn-group" style="display:none;">
                             <button id="save-secretary" class="btn btn-primary">
-                                <i class="fas fa-check-square mr-2"></i>
+                                <i class="fas fa-check-square me-2"></i>
                                 <?= lang('save') ?>
                             </button>
                             <button id="cancel-secretary" class="btn btn-outline-secondary">
-                                <i class="fas fa-ban mr-2"></i>
+                                <i class="fas fa-ban me-2"></i>
                                 <?= lang('cancel') ?>
                             </button>
                         </div>
@@ -630,26 +630,26 @@
                     <div class="btn-toolbar mb-4">
                         <div class="add-edit-delete-group btn-group">
                             <button id="add-admin" class="btn btn-primary">
-                                <i class="fas fa-plus-square mr-2"></i>
+                                <i class="fas fa-plus-square me-2"></i>
                                 <?= lang('add') ?>
                             </button>
                             <button id="edit-admin" class="btn btn-outline-secondary" disabled="disabled">
-                                <i class="fas fa-edit mr-2"></i>
+                                <i class="fas fa-edit me-2"></i>
                                 <?= lang('edit') ?>
                             </button>
                             <button id="delete-admin" class="btn btn-outline-secondary" disabled="disabled">
-                                <i class="fas fa-trash-alt mr-2"></i>
+                                <i class="fas fa-trash-alt me-2"></i>
                                 <?= lang('delete') ?>
                             </button>
                         </div>
 
                         <div class="save-cancel-group btn-group" style="display:none;">
                             <button id="save-admin" class="btn btn-primary">
-                                <i class="fas fa-check-square mr-2"></i>
+                                <i class="fas fa-check-square me-2"></i>
                                 <?= lang('save') ?>
                             </button>
                             <button id="cancel-admin" class="btn btn-outline-secondary">
-                                <i class="fas fa-ban mr-2"></i>
+                                <i class="fas fa-ban me-2"></i>
                                 <?= lang('cancel') ?>
                             </button>
                         </div>