update: h3 used instead of a class

src/styles/base/main.scss

@@ -143,6 +143,7 @@ h2, .h2-like {
 h3 {
   color: var(--color-title);
   font-size: 1.7rem;
+  margin: 0;
 }
 
 h4 {
@@ -269,6 +270,13 @@ h5 {
   }
 }
 
+.admin-header {
+  align-items: center;
+  display: flex;
+  justify-content: space-between;
+  margin-bottom: 5rem;
+}
+
 .backlink {
   @include icon('arrow-left-circle');
   color: var(--color-backlink);

src/styles/layout/circle/circle-admin.scss

-.admin-header {
-  display: flex;
-  justify-content: space-between;
-  margin-bottom: 5rem;
-
-  .admin-header__title {
-    @extend h3;
-  }
-}
\ No newline at end of file

src/views/admin/page-admin-circles.pug

@@ -30,7 +30,7 @@
 
       div.admin-header
 
-        div.admin-header__title Canaux
+        h3 Canaux
 
         sib-link(
           class='button text-bold text-uppercase reversed button-primary bordered with-icon icon-plus'

src/views/admin/page-admin-projects.pug

@@ -15,7 +15,7 @@
 
     div.content-box__info
       div.admin-header
-        div.admin-header__title Projets
+        h3 Projets
         sib-link(
           class='button text-bold text-uppercase reversed button-primary bordered with-icon icon-plus'
           next='admin-project-create'

src/views/admin/page-admin-users.pug

@@ -20,7 +20,7 @@
   #admin-users-list(hidden)
     div.content-box__info
       div.admin-header
-        div.admin-header__title Utilisateurs
+        h3 Utilisateurs
         sib-ac-checker(data-src=`${endpoints.users || endpoints.post.users}`, permission='acl:Append')
           sib-link(
             class='button text-bold text-uppercase reversed button-primary bordered with-icon icon-plus'