diff --git a/css/html_instruct_style.css b/css/html_instruct_style.css
index aa61f33b..fc20d166 100644
--- a/css/html_instruct_style.css
+++ b/css/html_instruct_style.css
@@ -19,15 +19,6 @@
     color: #d1d5db !important;
 }
 
-.chat .message-body :is(th, td),
-.prose hr {
-    border-color: #40404096 !important;
-}
-
-.dark .chat .message-body :is(th, td),
-.dark .prose hr {
-    border-color: rgb(255 255 255 / 30%) !important;
-}
 
 .chat .message-body :is(p, ul, ol) {
     margin: 1.25em 0 !important;
diff --git a/css/main.css b/css/main.css
index 459c9fab..d9dc5d2e 100644
--- a/css/main.css
+++ b/css/main.css
@@ -1958,14 +1958,24 @@ table, tr, td, th, thead {
     border: 0;
 }
 
+.prose hr {
+    border-color: var(--border-color-primary);
+}
+
 td + td,
-th + th { border-left: 1px solid; }
+th + th {
+    border-left: 1px solid var(--border-color-primary) !important;
+}
 
 tr + tr td,
-tr + tr th { border-top: 1px solid; }
+tr + tr th {
+    border-top: 1px solid var(--border-color-primary) !important;
+}
 
 thead + tbody tr:first-child td,
-thead + tbody tr:first-child th { border-top: 1px solid; }
+thead + tbody tr:first-child th {
+    border-top: 1px solid var(--border-color-primary) !important;
+}
 
 /* ------------------------------------------------
    Tools CheckboxGroup - vertical DragDrop-like style