diff --git a/userChrome.css b/userChrome.css
index f80927d..07e582b 100644
--- a/userChrome.css
+++ b/userChrome.css
@@ -3292,22 +3292,32 @@
     background-size: var(--tab-corner-rounding);
 
     /* Corner Rounding Color */
-    fill: none !important;
-    fill-opacity: var(--toolbarbutton-icon-fill-opacity) !important;
-    -moz-context-properties: fill, fill-opacity !important;
+    fill: transparent !important;
+    -moz-context-properties: fill !important;
   }
 
-  #tabs-newtab-button > .toolbarbutton-icon {
-    border-radius: var(--tab-border-radius) var(--tab-border-radius) 0 0 !important; /* Original: var(--tab-border-radius) */
-  }
-
-  /* Coner Rounding */
+  /* Corner Rounding Color */
   #tabs-newtab-button:hover {
-    /* Color */
     fill: var(--toolbarbutton-hover-background) !important;
   }
+  #tabs-newtab-button:hover:active {
+    fill: var(--toolbarbutton-active-background) !important;
+  }
+  @media (-moz-windows-accent-color-in-titlebar) {
+    :root[tabsintitlebar]:not(:-moz-window-inactive, :-moz-lwtheme) #tabs-newtab-button:hover,
+    :root[tabsintitlebar][lwt-default-theme-in-dark-mode]:not(:-moz-window-inactive) #tabs-newtab-button:hover {
+      fill: color-mix(in srgb, -moz-accent-color-foreground 10%, transparent) !important; /* Hardcorded for compatibility */
+    }
+    :root[tabsintitlebar]:not(:-moz-window-inactive, :-moz-lwtheme) #tabs-newtab-button:hover:active,
+    :root[tabsintitlebar][lwt-default-theme-in-dark-mode]:not(:-moz-window-inactive) #tabs-newtab-button:hover:active {
+      fill: color-mix(in srgb, -moz-accent-color-foreground 15%, transparent) !important; /* Hardcorded for compatibility */
+    }
+  }
 
+  /* '+'Icon */
   #tabs-newtab-button .toolbarbutton-icon {
+    border-radius: var(--tab-border-radius) var(--tab-border-radius) 0 0 !important; /* Original: var(--tab-border-radius) */
+
     padding: calc(var(--toolbarbutton-inner-padding) - (var(--tab-block-margin) / 4)) var(--toolbarbutton-inner-padding)
       calc(var(--toolbarbutton-inner-padding) + (var(--tab-block-margin) / 4) + var(--tabs-navbar-original-shadow-size)) !important;
     -moz-context-properties: fill, fill-opacity;