diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor
index 363c9a67..15f19278 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor
@@ -10,15 +10,58 @@
     <link rel="stylesheet" href="css/envelope-viewer.css" />
     <link rel="stylesheet" href="EnvelopeGenerator.Server.styles.css" />
     <HeadOutlet />
+    <!-- Apply saved theme immediately on page load — before WASM boots.
+         Reads localStorage["signflow.theme"] to avoid flash of default theme. -->
+    <script>
+        (function () {
+            var allowed = { 'blazing-dark': true, 'blazing-berry': true, 'purple': true };
+            var theme = localStorage.getItem('signflow.theme');
+            if (!theme || !allowed[theme]) theme = 'blazing-berry';
+            var bsTheme = theme === 'blazing-dark' ? 'dark' : 'light';
+            document.documentElement.setAttribute('data-sf-theme', theme);
+            document.documentElement.setAttribute('data-bs-theme', bsTheme);
+            var link = document.createElement('link');
+            link.id = 'dx-theme-link';
+            link.rel = 'stylesheet';
+            link.href = '_content/DevExpress.Blazor.Themes/' + theme + '.bs5.min.css';
+            document.head.appendChild(link);
+        })();
+    </script>
 </head>
 
 <body>
+    <!-- WASM boot loading overlay — hidden once Blazor circuit connects -->
+    <div id="sf-boot-overlay">
+        <div class="sf-boot-spinner">
+            <div class="sf-boot-ring"></div>
+        </div>
+    </div>
+
     <Routes />
     <script src="_content/DevExpress.Blazor.Resources/js/preload-script.js"></script>
     <script src="js/typed.umd.js"></script>
     <script src="js/receiver-signature.js?v=9"></script>
     <script src="js/signflow-theme.js"></script>
     <script src="_framework/blazor.web.js"></script>
+    <script>
+        // Remove the boot overlay once Blazor has started and enhanced navigation is active.
+        Blazor.addEventListener('enhancedload', function onFirstLoad() {
+            var overlay = document.getElementById('sf-boot-overlay');
+            if (overlay) overlay.style.opacity = '0';
+            setTimeout(function () { if (overlay) overlay.remove(); }, 250);
+            Blazor.removeEventListener('enhancedload', onFirstLoad);
+        });
+        // Also remove when WASM circuit is ready (for non-enhanced pages like /sender)
+        document.addEventListener('blazor-circuit-connected', function () {
+            var overlay = document.getElementById('sf-boot-overlay');
+            if (overlay) { overlay.style.opacity = '0'; setTimeout(function () { if (overlay) overlay.remove(); }, 250); }
+        }, { once: true });
+        // Fallback: remove after 4s regardless
+        setTimeout(function () {
+            var overlay = document.getElementById('sf-boot-overlay');
+            if (overlay) overlay.remove();
+        }, 4000);
+    </script>
 </body>
 
 </html>
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Controllers/CustomImagesController.cs b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Controllers/CustomImagesController.cs
new file mode 100644
index 00000000..3dc6fbba
--- /dev/null
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Controllers/CustomImagesController.cs
@@ -0,0 +1,26 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Options;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Server.Models;
+
+namespace EnvelopeGenerator.Server.Controllers;
+
+/// <summary>
+/// Exposes the CustomImages configuration (signFLOW logo + company logo) to WASM clients.
+/// Values are sourced from appsettings.json "CustomImages" section via Options Pattern.
+///
+/// To change logos per deployment: update "CustomImages.App.Src", "App.Height",
+/// "Company.Src", "Company.Height" in appsettings.json — no code change required.
+/// </summary>
+[ApiController]
+[Route("api/[controller]")]
+[Authorize(Policy = AuthPolicy.SenderOrReceiver)]
+public class CustomImagesController(IOptions<CustomImagesOptions> options) : ControllerBase
+{
+    /// <summary>
+    /// Returns the signFLOW app logo and company logo configuration.
+    /// </summary>
+    [HttpGet]
+    public ActionResult<CustomImagesOptions> Get() => Ok(options.Value);
+}
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs
index d8aadebd..d8de46d4 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs
@@ -326,12 +326,17 @@ try
     // User Preferences (theme, dark mode, grid layouts — stored in TBDD_CACHE)
     // Registration handled by Infrastructure DependencyInjection (AddEnvelopeGeneratorInfrastructureServices)
 
+    // CustomImages — logo sources and heights, configurable per deployment via appsettings.json
+    builder.Services.Configure<EnvelopeGenerator.Server.Models.CustomImagesOptions>(
+        config.GetSection(EnvelopeGenerator.Server.Models.CustomImagesOptions.SectionName));
+
     // Client-side services that MainLayout depends on must also be registered here
     // so that Blazor Auto prerender (SSR pass) can resolve them on the server.
     // ThemeService.InitializeAsync() uses IJSRuntime but is only called in OnAfterRenderAsync
     // (never during prerender), so registering it server-side is safe.
     builder.Services.AddScoped<EnvelopeGenerator.Server.Client.Services.UserPreferencesService>();
     builder.Services.AddScoped<EnvelopeGenerator.Server.Client.Services.ThemeService>();
+    builder.Services.AddScoped<EnvelopeGenerator.Server.Client.Services.CustomImagesService>();
 
     // Business Services (Server specific)
     builder.Services.AddScoped<DocumentService>();
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/appsettings.json b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/appsettings.json
index e763a015..a3a63a85 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/appsettings.json
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/appsettings.json
@@ -145,15 +145,17 @@
   "CustomImages": {
     "App": {
       "Src": "/img/DD_signFLOW_LOGO.png",
+      "Height": "28px",
       "Classes": {
-        "Main": "signFlow-logo"
+        "Main": "signflow-app-logo"
       }
     },
     "Company": {
       "Src": "/img/digital_data.svg",
+      "Height": "33px",
       "Classes": {
-        "Show": "dd-show-logo",
-        "Locked": "dd-locked-logo"
+        "Show": "signflow-company-logo",
+        "Locked": "signflow-company-logo"
       }
     }
   },
