diff --git a/src/compatibility/_theme.scss b/src/compatibility/_theme.scss
index 80bc974..a4c7497 100644
--- a/src/compatibility/_theme.scss
+++ b/src/compatibility/_theme.scss
@@ -5,6 +5,11 @@
   border-radius: 4px;
 }
 
+/*= Remote Tabs Panel's Bottom Padding =======================================*/
+#PanelUI-remotetabs #PanelUI-remotetabs-main {
+  margin-bottom: 6px;
+}
+
 /*= Identity Popup Icon Crop =================================================*/
 .identity-popup-security-connection.identity-button {
   padding-block: 1px !important;
@@ -66,9 +71,7 @@ menu[disabled="true"] {
   }
 }
 :root[lwtheme-image] #navigator-toolbox:-moz-lwtheme {
-  background-image: var(
-    --lwt-additional-images
-  ) !important; /* Original: var(--lwt-header-image), var(--lwt-additional-images); */
+  background-image: var(--lwt-header-image), var(--lwt-additional-images) !important;
   background-repeat: var(--lwt-background-tiling) !important;
   background-position: var(--lwt-background-alignment) !important;
   background-color: unset !important; /* Original:  var(--lwt-accent-color) */
@@ -76,5 +79,6 @@ menu[disabled="true"] {
 
 /* Navbar Border */
 #navigator-toolbox:-moz-lwtheme {
-  --tabs-border-color: rgba(0, 0, 0, 0.3);
+  --tabs-border-color: rgba(0, 0, 0, 0.3); /* Legacy: v96 */
+  --lwt-tabs-border-color: rgba(0, 0, 0, 0.3);
 }
diff --git a/src/contents/proton_contents/_proton_commons.scss b/src/contents/proton_contents/_proton_commons.scss
index b0c4410..94d566b 100644
--- a/src/contents/proton_contents/_proton_commons.scss
+++ b/src/contents/proton_contents/_proton_commons.scss
@@ -215,7 +215,7 @@
                url-prefix("about:cache"),
                url-prefix("about:checkerboard") {
   table {
-    border: 1px solid var(--in-content-border-color) !important;
+    border: 1px solid var(--in-content-table-border-color) !important;
     border-radius: 0 !important;
   }
 }
@@ -223,7 +223,7 @@
                url-prefix("about:checkerboard") {
   th,
   td {
-    border: 1px solid var(--in-content-border-color) !important;
+    border: 1px solid var(--in-content-table-border-color) !important;
   }
   th {
     background-color: var(--in-content-table-header-background) !important;
diff --git a/src/padding/_tabbar_height.scss b/src/padding/_tabbar_height.scss
index 158a74f..b7c437a 100644
--- a/src/padding/_tabbar_height.scss
+++ b/src/padding/_tabbar_height.scss
@@ -28,6 +28,9 @@
   #tabbrowser-tabs[positionpinnedtabs] > #tabbrowser-arrowscrollbox > .tabbrowser-tab[pinned] {
     min-height: var(--tab-min-height) !important;
   }
+  #tabbrowser-arrowscrollbox {
+    height: var(--tab-min-height);
+  }
 
   /* Top Margin */
   .tab-background,
diff --git a/src/tabbar/selected_tab/_photon_like_contextline.scss b/src/tabbar/selected_tab/_photon_like_contextline.scss
index 3535d2b..f500d7c 100644
--- a/src/tabbar/selected_tab/_photon_like_contextline.scss
+++ b/src/tabbar/selected_tab/_photon_like_contextline.scss
@@ -1,8 +1,10 @@
-:root[lwtheme-mozlightdark] #tabbrowser-tabs {
+:root[lwtheme-mozlightdark] #tabbrowser-tabs, /* Legacy: v96 */
+:root[style*="--lwt-accent-color: rgb(240, 240, 244); --lwt-text-color: rgba(21, 20, 26);"],
+:root[style*="--lwt-accent-color: rgb(28, 27, 34); --lwt-text-color: rgba(251, 251, 254);"] {
   --tab-line-color: rgb(10, 132, 255) !important;
 }
 @media (-moz-gtk-csd-available) {
-  :root[lwtheme-mozlightdark]:not(:-moz-lwtheme) #tabbrowser-tabs {
+  :root:not(:-moz-lwtheme) #tabbrowser-tabs {
     --tab-line-color: Highlight !important; /* -moz-accent-color */
   }
 }
diff --git a/src/tabbar/unselected_tab/_static_separator.scss b/src/tabbar/unselected_tab/_static_separator.scss
index bfd49d3..8bdde1f 100644
--- a/src/tabbar/unselected_tab/_static_separator.scss
+++ b/src/tabbar/unselected_tab/_static_separator.scss
@@ -30,6 +30,7 @@
 #tabbrowser-tabs:not([movingtab]) > #tabbrowser-arrowscrollbox > .tabbrowser-tab[beforeselected-visible]::after,
 #tabbrowser-tabs[movingtab] > #tabbrowser-arrowscrollbox > .tabbrowser-tab[visuallyselected]::before,
 .tabbrowser-tab[visuallyselected]::after {
+  --tabs-border-color: transparent;
   border-color: var(--tabs-border-color) !important;
   margin-top: 0 !important;
   margin-bottom: 0 !important;
diff --git a/src/theme/_proton_color.scss b/src/theme/_proton_color.scss
index 731843d..898973a 100644
--- a/src/theme/_proton_color.scss
+++ b/src/theme/_proton_color.scss
@@ -48,9 +48,9 @@
   --in-content-button-vertical-padding: 7px;
 
   --in-content-table-background: #f8f8fa;
-  --in-content-table-border-dark-color: #d1d1d1;
-  --in-content-table-header-background: #0a84ff;
-  --in-content-table-header-color: #ffffff;
+  --in-content-table-border-color: var(--in-content-box-border-color); /* Legacy: #d1d1d1; rgba(249, 249, 250, 0.2) */
+  --in-content-table-header-background: var(--in-content-primary-button-background); /* Legacy: #0a84ff; rgb(5, 64, 150); */
+  --in-content-table-header-color: var(--in-content-primary-button-text-color); /* Legacy: #ffffff; var(--in-content-page-color); */
   --in-content-sidebar-width: 240px;
 
   --dialog-warning-text-color: var(--red-60);
@@ -137,9 +137,7 @@
     --in-content-danger-button-background-active: #ffdfe7;
 
     --in-content-table-background: rgb(35, 34, 43);
-    --in-content-table-border-dark-color: rgba(249, 249, 250, 0.2);
-    --in-content-table-header-background: rgb(5, 64, 150);
-    --in-content-table-header-color: var(--in-content-page-color);
+    --in-content-table-border-dark-color: var(--in-content-box-border-color);
 
     --in-content-accent-color: var(--in-content-primary-button-background);
     --in-content-accent-color-active: var(--in-content-primary-button-background-hover);
diff --git a/src/theme/proton_chrome/_cert.scss b/src/theme/proton_chrome/_cert.scss
index 784fc0b..a0e6ffd 100644
--- a/src/theme/proton_chrome/_cert.scss
+++ b/src/theme/proton_chrome/_cert.scss
@@ -1,11 +1,8 @@
 /*= Delete Cert ==============================================================*/
 @-moz-document url("chrome://pippki/content/deletecert.xhtml")
 {
-  :root {
-    --in-content-border-color: color-mix(in srgb, currentColor 41%, transparent) !important;
-  }
   #certlist {
-    border: 1px solid var(--in-content-border-color) !important;
+    border: 1px solid var(--in-content-table-border-color) !important;
     border-radius: 4px !important;
   }
 }
@@ -13,9 +10,6 @@
 /*= Cert Exeption Dialog =====================================================*/
 @-moz-document url("chrome://pippki/content/exceptionDialog.xhtml")
 {
-  :root {
-    --in-content-border-color: color-mix(in srgb, currentColor 41%, transparent) !important;
-  }
   #locationTextBox {
     appearance: none !important;
     border: 1px solid var(--in-content-box-border-color) !important;
diff --git a/src/theme/proton_chrome/_page_info.scss b/src/theme/proton_chrome/_page_info.scss
index 5ef5a1d..1e38bbf 100644
--- a/src/theme/proton_chrome/_page_info.scss
+++ b/src/theme/proton_chrome/_page_info.scss
@@ -82,7 +82,7 @@
     -moz-appearance: none !important;
     color: var(--in-content-table-header-color) !important;
     background: var(--in-content-table-header-background) !important;
-    border: 1px solid var(--in-content-border-color) !important;
+    border: 1px solid var(--in-content-table-border-color) !important;
     padding: 4px !important;
     border-spacing: 0;
 
@@ -94,7 +94,7 @@
     -moz-appearance: none !important;
     color: var(--in-content-text-color) !important;
     background-color: var(--in-content-table-background) !important;
-    border: 1px solid var(--in-content-border-color) !important;
+    border: 1px solid var(--in-content-table-border-color) !important;
   }
 
   treechildren::-moz-tree-row(odd) {
@@ -110,7 +110,7 @@
   }
 
   treechildren::-moz-tree-cell {
-    border-inline: 1px solid var(--in-content-border-color) !important;
+    border-inline: 1px solid var(--in-content-table-border-color) !important;
     border-spacing: 0 !important;
     padding: 4px !important;
     margin: 0 !important;
@@ -141,6 +141,6 @@
   #topBar,
   #imagecontainerbox,
   #permList {
-    border-color: var(--in-content-border-color) !important;
+    border-color: var(--in-content-table-border-color) !important;
   }
 }
diff --git a/src/theme/proton_chrome/_proton_commons.scss b/src/theme/proton_chrome/_proton_commons.scss
index 12d97f5..40f531f 100644
--- a/src/theme/proton_chrome/_proton_commons.scss
+++ b/src/theme/proton_chrome/_proton_commons.scss
@@ -453,7 +453,7 @@
     border-bottom-left-radius: 0 !important;
     border-bottom-right-radius: 0 !important;
     padding-bottom: 1px !important;
-    box-shadow: inset 0 -1px var(--in-content-border-color) !important;
+    box-shadow: inset 0 -1px var(--in-content-table-border-color) !important;
     overflow: clip !important; /* Clip border-radius */
   }
 
diff --git a/src/theme/system_default_theme/_mac.scss b/src/theme/system_default_theme/_mac.scss
index d2d5fc1..81b3a77 100644
--- a/src/theme/system_default_theme/_mac.scss
+++ b/src/theme/system_default_theme/_mac.scss
@@ -189,6 +189,9 @@
     --button-active-bgcolor: var(--mac-hover-bgcolor);
     --toolbarbutton-hover-background: var(--mac-hover-bgcolor);
     --toolbarbutton-active-background: var(--mac-hover-bgcolor);
+
+    /* Prevent transparent tabbar at fullscreen hover #312 */
+    background: var(--mac-bgcolor);
   }
 
   :root[lwt-default-theme-in-dark-mode] #urlbar {