feat: unify trading workspace visual system

app/frontend/shared/components/navigation.css

@@ -114,7 +114,7 @@
 
   border-radius: 8px;
 
-  background: rgb(243, 244, 246);
+  background: var(--surface-muted);
 }
 
 .redesigned-page-head .segment {
@@ -134,7 +134,7 @@
 }
 
 .redesigned-page-head .segment.active {
-  background: rgb(255, 255, 255);
+  background: var(--surface);
 
   color: var(--r2-ink);
 
@@ -204,7 +204,7 @@
 .seg {
   display: inline-flex;
 
-  background: rgb(243, 244, 246);
+  background: var(--surface-muted);
 
   border-radius: 8px;