header: make the header even narrower on mobile

This ensures that the help button is displayed on mobile devices.

app/assets/stylesheets/new_design/new_header.scss

@@ -3,7 +3,8 @@
 @import "constants";
 @import "mixins";
 
-$landing-breakpoint: 1040px;
+$header-landing-breakpoint: 1040px;
+$header-mobile-breakpoint: 550px;
 
 // FIXME: Rename when the header is generalized
 .new-header {
@@ -23,25 +24,29 @@ $landing-breakpoint: 1040px;
 
 .header-logo {
   display: inline-block;
+  height: 100%;
+  background-size: contain;
+  background-position: center;
+  background-repeat: no-repeat;
 
-  .header-logo-wide {
+  // Logo large
+  background-image: url("/assets/header/logo-ds-wide.svg");
+  width: 360px;
   margin-right: 4 * $default-spacer;
+
+  // Logo normal
+  @media (max-width: $header-landing-breakpoint) {
+    background-image: url("/assets/header/logo-ds.svg");
+    width: 132px;
+    margin-right: $default-spacer;
   }
 
-  .header-logo-narrow {
+  // Logo narrow
-    display: none;
+  @media (max-width: $header-mobile-breakpoint) {
-  }
+    background-image: url("/assets/header/logo-ds-narrow.svg");
-
+    width: 32px;
-  @media (max-width: $landing-breakpoint) {
-    .header-logo-wide {
-      display: none;
-    }
-
-    .header-logo-narrow {
-      display: inline;
     margin-right: 0;
   }
-  }
 }
 
 .header-tabs {

app/views/layouts/_new_header.haml

@@ -6,9 +6,7 @@
   .header-inner-content
 
     .flex.align-center
-      = link_to root_path_for_profile(nav_bar_profile), class: "header-logo" do
+      = link_to '', root_path_for_profile(nav_bar_profile), class: "header-logo", title: "Revenir à l’accueil"
-        = image_tag "header/logo-ds.svg", alt: "demarches-simplifiees.fr", class: "header-logo-wide"
-        = image_tag "header/logo-ds-narrow.svg", alt: "demarches-simplifiees.fr", class: "header-logo-narrow"
 
       - if nav_bar_profile == :gestionnaire && gestionnaire_signed_in?
         - current_url = request.path_info