feat(app): refine session UI styling (#33860)

Co-authored-by: Brendan Allan <14191578+Brendonovich@users.noreply.github.com>

packages/session-ui/src/components/session-turn.css

@@ -71,7 +71,7 @@
   }
 
   .error-card {
-    color: var(--text-on-critical-base);
+    color: var(--v2-text-text-base);
     max-height: 240px;
     white-space: pre-wrap;
     overflow-wrap: anywhere;
@@ -102,7 +102,7 @@
     position: sticky;
     top: var(--sticky-accordion-top, 0px);
     z-index: 20;
-    background-color: var(--background-stronger);
+    background-color: var(--v2-background-bg-base);
     height: 44px;
   }
 
@@ -226,6 +226,16 @@
   }
 }
 
+body:not([data-new-layout]) [data-component="session-turn"] {
+  .error-card {
+    color: var(--text-on-critical-base);
+  }
+
+  [data-slot="session-turn-diffs-header"] {
+    background-color: var(--background-stronger);
+  }
+}
+
 [data-slot="session-turn-list"] {
   gap: 24px;
 }