diff --git a/frontend/src/components/WalletBalance.tsx b/frontend/src/components/WalletBalance.tsx
index e52c4c5..abfae57 100644
--- a/frontend/src/components/WalletBalance.tsx
+++ b/frontend/src/components/WalletBalance.tsx
@@ -1,63 +1,76 @@
 'use client';
 
-/**
- * WalletBalance Component
- * Displays the connected wallet's STX balance with real-time updates
- * @module WalletBalance
- * @version 2.3.0
- */
-
-import { useState, useEffect, useCallback } from 'react';
+import { useState, useEffect, useCallback, useRef } from 'react';
 import { useWallet } from '@/hooks/useWallet';
 import { fetchSTXBalance } from '@/lib/api';
+import { toast } from 'react-hot-toast';
 
-// Balance display configuration
 const MICROSTX_DIVISOR = 1_000_000;
-const BALANCE_DECIMALS = 4;
-const LOADING_PLACEHOLDER = '...';
-
-/** Auto-refresh interval in milliseconds */
 const REFRESH_INTERVAL = 30000;
+const BALANCE_DECIMALS = 4;
 
-/** Animation duration for balance updates */
-const UPDATE_ANIMATION_DURATION = 300;
-
-/**
- * Balance display state
- */
-type BalanceState = 'idle' | 'loading' | 'success' | 'error';
+const FIAT_OPTIONS = [
+  { label: 'USD', rate: 0.42 },
+  { label: 'EUR', rate: 0.39 },
+  { label: 'GBP', rate: 0.34 },
+];
 
 export default function WalletBalance() {
   const { address, isConnected } = useWallet();
-  const [balance, setBalance] = useState<string | null>(null);
+  const [balance, setBalance] = useState<number | null>(null);
+  const [displayBalance, setDisplayBalance] = useState<number>(0);
   const [isLoading, setIsLoading] = useState(true);
-  const [lastUpdated, setLastUpdated] = useState<Date | null>(null);
   const [isRefreshing, setIsRefreshing] = useState(false);
+  const [lastUpdated, setLastUpdated] = useState<Date | null>(null);
+  const [error, setError] = useState<string | null>(null);
+
+  // Fiat currency state
+  const [fiat, setFiat] = useState(FIAT_OPTIONS[0]);
+
+  // Dark mode toggle
+  const [darkMode, setDarkMode] = useState(true);
+
+  const rafRef = useRef<number | null>(null);
+
+  const animateBalance = useCallback((from: number, to: number, duration = 300) => {
+    const start = performance.now();
+    const step = (timestamp: number) => {
+      const progress = Math.min((timestamp - start) / duration, 1);
+      setDisplayBalance(from + (to - from) * progress);
+      if (progress < 1) rafRef.current = requestAnimationFrame(step);
+    };
+    rafRef.current = requestAnimationFrame(step);
+  }, []);
 
   const fetchBalance = useCallback(async () => {
     if (!address) return;
-    
+    setIsRefreshing(true);
+    setError(null);
+
     try {
-      setIsRefreshing(true);
       const data = await fetchSTXBalance(address);
-      const stx = data.balance / 1000000;
-      setBalance(stx.toFixed(4));
+      const stx = data.balance / MICROSTX_DIVISOR;
+      setBalance(stx);
+      animateBalance(displayBalance, stx);
       setLastUpdated(new Date());
-    } catch (error) {
-      console.error('Failed to fetch balance:', error);
+    } catch (err) {
+      console.error(err);
+      setError('Failed to fetch balance. Retry?');
+      toast.error('Failed to fetch wallet balance.');
     } finally {
       setIsLoading(false);
       setIsRefreshing(false);
     }
-  }, [address]);
+  }, [address, displayBalance, animateBalance]);
 
   useEffect(() => {
     if (address) {
       fetchBalance();
-      
-      // Auto-refresh every 30 seconds
       const interval = setInterval(fetchBalance, REFRESH_INTERVAL);
-      return () => clearInterval(interval);
+      return () => {
+        clearInterval(interval);
+        if (rafRef.current) cancelAnimationFrame(rafRef.current);
+      };
     }
   }, [address, fetchBalance]);
 
@@ -68,16 +81,32 @@ export default function WalletBalance() {
     return `${minutes}m ago`;
   };
 
+  const handleCopyAddress = () => {
+    if (address) {
+      navigator.clipboard.writeText(address);
+      toast.success('Address copied to clipboard');
+    }
+  };
+
   if (!isConnected) return null;
 
-  // Mock USD value (in real app, fetch from API)
-  const usdValue = balance ? (parseFloat(balance) * 0.42).toFixed(2) : '0.00';
+  const fiatValue = balance ? (balance * fiat.rate).toFixed(2) : '0.00';
 
   return (
-    <div className="bg-gradient-to-br from-gray-900/90 to-gray-900/70 border border-purple-500/20 rounded-2xl p-6 backdrop-blur-sm relative overflow-hidden">
-      {/* Background decoration */}
+    <div className={`${darkMode ? 'bg-gray-900/90 text-white' : 'bg-white text-gray-900'} border border-purple-500/20 rounded-2xl p-6 backdrop-blur-sm relative overflow-hidden transition-colors duration-300`}>
       <div className="absolute -top-12 -right-12 w-24 h-24 bg-purple-500/10 rounded-full blur-2xl pointer-events-none" />
-      
+
+      {/* Dark/Light toggle */}
+      <div className="absolute top-4 right-4">
+        <button
+          className="p-1 bg-gray-700/30 dark:bg-gray-200/30 rounded-full"
+          onClick={() => setDarkMode(!darkMode)}
+          title="Toggle Dark/Light Mode"
+        >
+          {darkMode ? '🌙' : '☀️'}
+        </button>
+      </div>
+
       <div className="relative">
         {/* Header */}
         <div className="flex items-center justify-between mb-4">
@@ -85,25 +114,34 @@ export default function WalletBalance() {
             <div className="w-8 h-8 bg-gradient-to-br from-purple-500 to-pink-500 rounded-lg flex items-center justify-center">
               <span className="text-sm">💰</span>
             </div>
-            <span className="text-gray-300 font-medium">Wallet Balance</span>
+            <span className="font-medium">Wallet Balance</span>
           </div>
-          <button 
-            onClick={fetchBalance}
-            disabled={isRefreshing}
-            className="p-2 text-gray-400 hover:text-purple-400 hover:bg-purple-500/10 rounded-lg transition-all disabled:opacity-50"
-            title="Refresh balance"
-          >
-            <svg 
-              className={`w-4 h-4 ${isRefreshing ? 'animate-spin' : ''}`} 
-              fill="none" 
-              stroke="currentColor" 
-              viewBox="0 0 24 24"
+          <div className="flex items-center gap-2">
+            <button 
+              onClick={fetchBalance}
+              disabled={isRefreshing}
+              className="p-2 text-gray-400 hover:text-purple-400 hover:bg-purple-500/10 rounded-lg transition-all disabled:opacity-50"
+              title="Refresh balance"
             >
-              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15" />
-            </svg>
-          </button>
+              <svg 
+                className={`w-4 h-4 ${isRefreshing ? 'animate-spin' : ''}`} 
+                fill="none" 
+                stroke="currentColor" 
+                viewBox="0 0 24 24"
+              >
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15" />
+              </svg>
+            </button>
+            <button
+              onClick={handleCopyAddress}
+              className="p-2 text-gray-400 hover:text-purple-400 hover:bg-purple-500/10 rounded-lg transition-all"
+              title="Copy wallet address"
+            >
+              📋
+            </button>
+          </div>
         </div>
-        
+
         {/* Balance Display */}
         <div className="text-center py-4">
           {isLoading ? (
@@ -111,19 +149,35 @@ export default function WalletBalance() {
               <div className="h-10 w-32 bg-gray-700 rounded-lg mx-auto mb-2" />
               <div className="h-4 w-20 bg-gray-700 rounded mx-auto" />
             </div>
+          ) : error ? (
+            <div className="text-red-500 text-sm">{error}</div>
           ) : (
             <>
-              <p className={`text-4xl font-bold text-white transition-all ${isRefreshing ? 'opacity-50' : ''}`}>
-                {balance || '0.0000'} 
+              <p className={`text-4xl font-bold transition-all ${isRefreshing ? 'opacity-50' : ''}`}>
+                {displayBalance.toFixed(BALANCE_DECIMALS)}
                 <span className="text-2xl text-purple-400 ml-1">STX</span>
               </p>
-              <p className="text-gray-500 text-sm mt-1">
-                ≈ ${usdValue} USD
+              <p className="text-sm mt-1">
+                ≈ {fiatValue} {fiat.label}
               </p>
+
+              {/* Fiat selector */}
+              <select
+                className="mt-2 px-2 py-1 rounded-lg border border-gray-400 bg-gray-800/20 text-sm text-white"
+                value={fiat.label}
+                onChange={(e) => {
+                  const selected = FIAT_OPTIONS.find(f => f.label === e.target.value);
+                  if (selected) setFiat(selected);
+                }}
+              >
+                {FIAT_OPTIONS.map((f) => (
+                  <option key={f.label} value={f.label}>{f.label}</option>
+                ))}
+              </select>
             </>
           )}
         </div>
-        
+
         {/* Quick Actions */}
         <div className="grid grid-cols-2 gap-3 mt-4">
           <button className="flex items-center justify-center gap-2 py-3 bg-purple-600/20 hover:bg-purple-600 text-purple-400 hover:text-white rounded-xl font-medium transition-all">
@@ -135,10 +189,10 @@ export default function WalletBalance() {
             <span className="text-sm">Receive</span>
           </button>
         </div>
-        
+
         {/* Last Updated */}
         {lastUpdated && (
-          <p className="text-center text-xs text-gray-500 mt-4">
+          <p className="text-center text-xs mt-4">
             Last updated {formatTimeAgo(lastUpdated)}
           </p>
         )}