diff --git a/mastodon/app/javascript/styles/tangerineui-cherry/tangerineui-cherry.scss b/mastodon/app/javascript/styles/tangerineui-cherry/tangerineui-cherry.scss
index 2add4dc..6a9dbbd 100644
--- a/mastodon/app/javascript/styles/tangerineui-cherry/tangerineui-cherry.scss
+++ b/mastodon/app/javascript/styles/tangerineui-cherry/tangerineui-cherry.scss
@@ -3508,9 +3508,14 @@ div[tabindex="-1"] + div[tabindex="-1"] > .status__wrapper > .status-reply.statu
 }
 
 .app-body .column-header__collapsible {
-    background-color: var(--color-content-secondary-bg);
+    background-color: color-mix(in srgb, var(--color-content-secondary-bg), transparent 15%);
+    -webkit-backdrop-filter: blur(15px);
+    backdrop-filter: blur(15px);
     border-left: 1px solid var(--color-lines);
     border-right: 1px solid var(--color-lines);
+    border-bottom: 0;
+}
+.app-body .column-header__collapsible:is(:not(.collapsed), .animating) {
     border-bottom: 1px solid var(--color-lines);
 }
 .app-body .column-header__collapsible::-webkit-scrollbar-track {
diff --git a/mastodon/app/javascript/styles/tangerineui-purple/tangerineui-purple.scss b/mastodon/app/javascript/styles/tangerineui-purple/tangerineui-purple.scss
index 93d1612..a7c9479 100644
--- a/mastodon/app/javascript/styles/tangerineui-purple/tangerineui-purple.scss
+++ b/mastodon/app/javascript/styles/tangerineui-purple/tangerineui-purple.scss
@@ -3508,9 +3508,14 @@ div[tabindex="-1"] + div[tabindex="-1"] > .status__wrapper > .status-reply.statu
 }
 
 .app-body .column-header__collapsible {
-    background-color: var(--color-content-secondary-bg);
+    background-color: color-mix(in srgb, var(--color-content-secondary-bg), transparent 15%);
+    -webkit-backdrop-filter: blur(15px);
+    backdrop-filter: blur(15px);
     border-left: 1px solid var(--color-lines);
     border-right: 1px solid var(--color-lines);
+    border-bottom: 0;
+}
+.app-body .column-header__collapsible:is(:not(.collapsed), .animating) {
     border-bottom: 1px solid var(--color-lines);
 }
 .app-body .column-header__collapsible::-webkit-scrollbar-track {
diff --git a/mastodon/app/javascript/styles/tangerineui/tangerineui.scss b/mastodon/app/javascript/styles/tangerineui/tangerineui.scss
index 637b663..752efb9 100644
--- a/mastodon/app/javascript/styles/tangerineui/tangerineui.scss
+++ b/mastodon/app/javascript/styles/tangerineui/tangerineui.scss
@@ -3508,9 +3508,14 @@ div[tabindex="-1"] + div[tabindex="-1"] > .status__wrapper > .status-reply.statu
 }
 
 .app-body .column-header__collapsible {
-    background-color: var(--color-content-secondary-bg);
+    background-color: color-mix(in srgb, var(--color-content-secondary-bg), transparent 15%);
+    -webkit-backdrop-filter: blur(15px);
+    backdrop-filter: blur(15px);
     border-left: 1px solid var(--color-lines);
     border-right: 1px solid var(--color-lines);
+    border-bottom: 0;
+}
+.app-body .column-header__collapsible:is(:not(.collapsed), .animating) {
     border-bottom: 1px solid var(--color-lines);
 }
 .app-body .column-header__collapsible::-webkit-scrollbar-track {
@@ -3538,7 +3543,6 @@ div[tabindex="-1"] + div[tabindex="-1"] > .status__wrapper > .status-reply.statu
     }
 }
 .app-body .column-header__collapsible-inner {
-    background: var(--color-content-secondary-bg);
     border: 0;
 }
 .app-body .column-settings__section {