feat: unify trading workspace visual system

frontend/shared/auth.css

@@ -315,7 +315,7 @@
 
   border-radius: 4px;
 
-  background: rgb(255, 255, 255);
+  background: var(--surface);
 }
 
 .membership-expiry {
@@ -729,7 +729,7 @@ button.account-role-badge:focus-visible {
 .vip-role-badge.is-nonmember b {
   background: rgb(135, 147, 158);
 
-  color: rgb(255, 255, 255);
+  color: var(--text-inverse);
 }
 
 .vip-role-badge b {
@@ -1216,7 +1216,7 @@ button.account-role-badge:focus-visible {
 
   background: rgb(37, 99, 235);
 
-  color: rgb(255, 255, 255);
+  color: var(--text-inverse);
 
   box-shadow: none;
 
@@ -1401,7 +1401,7 @@ button.account-role-badge:focus-visible {
 
   border-radius: 7px;
 
-  background: rgb(248, 250, 252);
+  background: var(--table-header);
 }
 
 .account-settings-dialog .membership-status-grid span {
@@ -1439,7 +1439,7 @@ button.account-role-badge:focus-visible {
 }
 
 .account-settings-dialog .membership-comparison-head {
-  background: rgb(245, 247, 249);
+  background: var(--table-header);
 }
 
 .account-settings-dialog .membership-topup-row {