diff --git a/group_vars/all/03_domains.yml b/group_vars/all/03_domains.yml
index 4e46a5b9..361f7970 100644
--- a/group_vars/all/03_domains.yml
+++ b/group_vars/all/03_domains.yml
@@ -19,7 +19,7 @@ defaults_domains:
   keycloak:                "auth.{{primary_domain}}"
   ldap:                    "ldap.{{primary_domain}}"
   listmonk:                "newsletter.{{primary_domain}}"
-  mailu:                   "{{system_email.host}}"
+  mailu:                   "mail.{{primary_domain}}"
   mastodon:                "microblog.{{primary_domain}}"
   # ATTENTION: Will be owerwritten by the values in domains. Not merged.
   mastodon_alternates:    ["mastodon.{{primary_domain}}"]
@@ -54,6 +54,7 @@ defaults_redirect_domain_mappings:
 - { source: "gitea.{{primary_domain}}",       target: "{{domains.gitea}}" }
 - { source: "keycloak.{{primary_domain}}",    target: "{{domains.keycloak}}" }
 - { source: "listmonk.{{primary_domain}}",    target: "{{domains.listmonk}}" }
+- { source: "mail.{{primary_domain}}",        target: "{{domains.mailu}}" }
 - { source: "moodle.{{primary_domain}}",      target: "{{domains.moodle}}" }
 - { source: "nextcloud.{{primary_domain}}",   target: "{{domains.nextcloud}}" }
 - { source: "openproject.{{primary_domain}}", target: "{{domains.openproject}}" }
diff --git a/roles/nginx-modifier-css/templates/global.css.j2 b/roles/nginx-modifier-css/templates/global.css.j2
index 57ffb954..bea30a31 100644
--- a/roles/nginx-modifier-css/templates/global.css.j2
+++ b/roles/nginx-modifier-css/templates/global.css.j2
@@ -376,8 +376,8 @@ HINT:
   --pf-v5-global--BackgroundColor--dark-200:         var(--color-25);
   --pf-v5-global--BackgroundColor--dark-300:         var(--color-20);
   --pf-v5-global--BackgroundColor--dark-400:         var(--color-30);
-  --pf-v5-global--BackgroundColor--dark-transparent-100: var(--color-05);
-  --pf-v5-global--BackgroundColor--dark-transparent-200: var(--color-05);
+  --pf-v5-global--BackgroundColor--dark-transparent-100: rgba(var(--color-rgb-10),0.7);
+  --pf-v5-global--BackgroundColor--dark-transparent-200: rgba(var(--color-rgb-20),0.8);
 
   /* --- Color Variables --- */
   --pf-v5-global--Color--100:           var(--color-10);
@@ -549,7 +549,6 @@ body#custom-css {
     --textareaBackgroundColor: var(--color-99); /* Original tone: #fff – white */
     --markdownTextareaBackgroundColor: var(--color-91); /* Original tone: #EFEFEF – very light gray */
     --actionButtonColor: var(--color-50); /* Original tone: #585858 – medium gray */
-    --supportButtonBackgroundColor: transparent; /* Original tone: transparent */
     --supportButtonColor: var(--actionButtonColor); /* Original tone: same as actionButtonColor (#585858) */
     --activatedActionButtonColor: var(--color-10); /* Original tone: #212529 – dark gray */
     color: var(--mainForegroundColor);
@@ -869,6 +868,11 @@ div#app header, div#app header *{
     border-color:     transparent;
 }
 
+ul.lam-tab-navigation {
+    background: rgba(var(--color-rgb-90), 0.1);
+    border-color:      transparent;
+}
+
 /* Not changable due to inline css */
 .roundedShadowBox {
     color: #000000;