Fix: TitleBar - Remove native titlebar button style at linux

The title bar is not visible in v140
5ce8bb770f

css/leptonChrome.css

@@ -252,25 +252,6 @@
     }
     /*= Linux - Titlebar button at lwtheme =====================================*/
     @media not -moz-pref("userChrome.compatibility.os.linux_non_native_titlebar_button") {
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button {
-        appearance: none !important;
-      }
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button > .toolbarbutton-icon {
-        appearance: auto !important;
-        width: unset !important;
-        height: unset !important;
-      }
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-min,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-max,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-restore,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-close {
-        list-style-image: none !important;
-      }
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button:hover:active {
-        background-color: unset !important;
-        color: unset !important;
-      }
     }
   }
   /*= Linux - Light System Default Theme's Selected Tab ========================*/
@@ -14419,27 +14400,6 @@
   }
   /*= Linux - Titlebar button at lwtheme =====================================*/
 }
-@media (-moz-bool-pref: "userChrome.compatibility.os") and (-moz-gtk-csd-available) and (not (-moz-bool-pref: "userChrome.compatibility.os.linux_non_native_titlebar_button")) {
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button {
-    appearance: none !important;
-  }
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button > .toolbarbutton-icon {
-    appearance: auto !important;
-    width: unset !important;
-    height: unset !important;
-  }
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-min,
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-max,
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-restore,
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-close {
-    list-style-image: none !important;
-  }
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button,
-  :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button:hover:active {
-    background-color: unset !important;
-    color: unset !important;
-  }
-}
 @media (-moz-bool-pref: "userChrome.compatibility.os") and (-moz-gtk-csd-available) and (prefers-color-scheme: light) {
   /* Because of
     #TabsToolbar:not([brighttext]) #tabbrowser-tabs:not([noshadowfortests]) .tabbrowser-tab:is([visuallyselected], [multiselected]) > .tab-stack > .tab-background {

css/leptonChromeESR.css

@@ -380,27 +380,6 @@
       background-color: color-mix(in srgb, currentColor 20%, transparent) !important; /* Original: -moz-menuhover */
     }
     /*= Linux - Titlebar button at lwtheme =====================================*/
-    @supports not -moz-bool-pref("userChrome.compatibility.os.linux_non_native_titlebar_button") {
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button {
-        appearance: none !important;
-      }
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button > .toolbarbutton-icon {
-        appearance: auto !important;
-        width: unset !important;
-        height: unset !important;
-      }
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-min,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-max,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-restore,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-close {
-        list-style-image: none !important;
-      }
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button,
-      :root:is(:-moz-lwtheme, [lwtheme]) .titlebar-button:hover:active {
-        background-color: unset !important;
-        color: unset !important;
-      }
-    }
   }
   /*= Linux - Light System Default Theme's Selected Tab ========================*/
   @media (-moz-gtk-csd-available) and (-moz-toolbar-prefers-color-scheme: light),

src/compatibility/_os.scss

@@ -167,31 +167,6 @@
     color: inherit !important; /* Original: -moz-menubarhovertext */
     background-color: color-mix(in srgb, currentColor 20%, transparent) !important; /* Original: -moz-menuhover */
   }
-
-  /*= Linux - Titlebar button at lwtheme =====================================*/
-  @include NotOption("userChrome.compatibility.os.linux_non_native_titlebar_button") {
-    @include lwtheme {
-      .titlebar-button {
-        appearance: none !important;
-        > .toolbarbutton-icon {
-          appearance: auto !important;
-          width: unset !important;
-          height: unset !important;
-        }
-      }
-      .titlebar-min,
-      .titlebar-max,
-      .titlebar-restore,
-      .titlebar-close {
-        list-style-image: none !important;
-      }
-      .titlebar-button,
-      .titlebar-button:hover:active {
-        background-color: unset !important;
-        color: unset !important;
-      }
-    }
-  }
 }
 
 /*= Linux - Light System Default Theme's Selected Tab ========================*/

user.js

@@ -57,7 +57,6 @@ user_pref("userChrome.rounding.square_tab",           false);
 // user_pref("userChrome.compatibility.navbar_top_border",    true);
 // user_pref("userChrome.compatibility.dynamic_separator",    true); // Need dynamic_separator
 
-// user_pref("userChrome.compatibility.os.linux_non_native_titlebar_button", true);
 // user_pref("userChrome.compatibility.os.windows_maximized", true);
 // user_pref("userChrome.compatibility.os.win11",             true);