diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index 1bccfa0..11b4889 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -5374,6 +5374,19 @@
     }
   }
 }
+@supports -moz-bool-pref("userChrome.sidebar.hidden_header") {
+  @supports not -moz-bool-pref("userChrome.sidebar.hidden_header.vertical_tab_only") {
+    #sidebar-header {
+      display: none !important;
+    }
+  }
+  @supports -moz-bool-pref("userChrome.sidebar.hidden_header.vertical_tab_only") {
+    #sidebar-box:is([sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"], [sidebarcommand="tabcenter-reborn_ariasuni-sidebar-action"])
+      #sidebar-header {
+      display: none !important;
+    }
+  }
+}
 /** Other UI ******************************************************************/
 /*= Bookmark Bar - Centered ==================================================*/
 @supports -moz-bool-pref("userChrome.bookmarkbar.centered") {
diff --git a/src/sidebar/_hidden.scss b/src/sidebar/_hidden.scss
new file mode 100644
index 0000000..94f6001
--- /dev/null
+++ b/src/sidebar/_hidden.scss
@@ -0,0 +1,14 @@
+@include NotOption("userChrome.sidebar.hidden_header.vertical_tab_only") {
+  #sidebar-header {
+    display: none !important;
+  }
+}
+
+@include Option("userChrome.sidebar.hidden_header.vertical_tab_only") {
+  #sidebar-box:is(
+    [sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"],
+    [sidebarcommand="tabcenter-reborn_ariasuni-sidebar-action"]
+  ) #sidebar-header {
+    display: none !important;
+  }
+}
diff --git a/src/sidebar/_index.scss b/src/sidebar/_index.scss
new file mode 100644
index 0000000..27c61d0
--- /dev/null
+++ b/src/sidebar/_index.scss
@@ -0,0 +1,5 @@
+@import "overlap";
+
+@include Option("userChrome.sidebar.hidden_header") {
+  @import "hidden";
+}
diff --git a/src/sidebar/_overlap.scss b/src/sidebar/_overlap.scss
new file mode 100644
index 0000000..59c0a22
--- /dev/null
+++ b/src/sidebar/_overlap.scss
@@ -0,0 +1,45 @@
+@include Option("userChrome.sidebar.overlap", "userChrome.autohide.sidebar") {
+  #sidebar-box {
+    /* Original
+    min-width: 14em;
+    width: 18em;
+    max-width: 36em;
+   */
+
+    --uc-sidebar-width: 40px;
+    --uc-sidebar-activate-width: 18em;
+    --uc-sidebar-fullscreen-width: 4px;
+    --uc-sidebar-shadow-color: #28282F;
+    --uc-autohide-sidebar-delay: 600ms; /* Wait 0.6s before hiding sidebar */
+
+    z-index: 1000 !important;
+    position: relative !important;
+
+    box-shadow: 1px 0px 15px -10px var(--uc-sidebar-shadow-color);
+  }
+
+  #sidebar-splitter {
+    display: none !important;
+  }
+}
+
+@include Option("userChrome.sidebar.overlap") {
+  @include NotOption("userChrome.autohide.sidebar") {
+    #sidebar-box {
+      min-width: var(--uc-sidebar-activate-width) !important;
+      max-width: var(--uc-sidebar-activate-width) !important;
+      margin-inline-start: calc(-1 * var(--uc-sidebar-activate-width)) !important;
+
+      will-change: transform;
+
+      &:not([hidden="true"]) {
+        transform: translateX(var(--uc-sidebar-activate-width));
+      }
+
+      @include Animate {
+        transition: transform 0.25s var(--animation-easing-function), opacity 0.25s ease-in-out,
+                    visibility 0s linear !important;
+      }
+    }
+  }
+}
diff --git a/user.js b/user.js
index fbaa1f5..6d46603 100644
--- a/user.js
+++ b/user.js
@@ -116,6 +116,8 @@ user_pref("userChrome.tab.bottom_rounded_corner",      true);
 // user_pref("userChrome.panel.full_width_separator",          true);
 // user_pref("userChrome.panel.full_width_padding",            true);
 
+// user_pref("userChrome.sidebar.hidden_header",               true);
+// user_pref("userChrome.sidebar.hidden_header.vertical_tab_only", true);
 // user_pref("userChrome.sidebar.overlap",                     true);
 
 // user_pref("userChrome.icon.account_image_to_right",         true);