diff --git a/src/routes/+layout.ts b/src/routes/+layout.ts
index 7257ce1f..838fc0be 100644
--- a/src/routes/+layout.ts
+++ b/src/routes/+layout.ts
@@ -396,19 +396,52 @@ export async function load({ fetch, params, parent, route, url }) {
     // Apply site-level theme defaults only when there is no persisted ae_loc
     // in localStorage (first-run). URL params and manual selection still override.
     try {
-        const scfg = ae_loc_init['site_cfg_json'] as any;
-        let has_persisted_ae_loc = false;
-        if (typeof localStorage !== 'undefined') {
+        // site_cfg_json may be an object or a JSON string depending on the API/backend.
+        let scfg_raw = ae_loc_init['site_cfg_json'];
+        let scfg: any = scfg_raw;
+        if (typeof scfg_raw === 'string') {
             try {
-                const raw = localStorage.getItem('ae_loc');
-                if (raw) has_persisted_ae_loc = true;
+                scfg = JSON.parse(scfg_raw);
             } catch (e) {
-                has_persisted_ae_loc = false;
+                scfg = {};
             }
         }
 
-        if (scfg && typeof scfg === 'object' && !has_persisted_ae_loc) {
-            if (scfg.theme_name) ae_loc_init['theme_name'] = scfg.theme_name;
+        // Inspect persisted `ae_loc` in localStorage to determine whether the
+        // user has already selected a theme. Some persisted-store implementations
+        // write a default `ae_loc` object immediately, so the mere presence of
+        // the key is not a reliable indicator of a user choice.
+        let persistedRaw: string | null = null;
+        try {
+            if (typeof localStorage !== 'undefined') persistedRaw = localStorage.getItem('ae_loc');
+        } catch (e) {
+            persistedRaw = null;
+        }
+
+        let persistedObj: any = null;
+        let persistedHasUserTheme = false;
+        if (persistedRaw) {
+            try {
+                persistedObj = JSON.parse(persistedRaw);
+            } catch (e) {
+                persistedObj = null;
+            }
+            if (persistedObj) {
+                // Explicit flag wins.
+                if (persistedObj.user_theme_selected === true) {
+                    persistedHasUserTheme = true;
+                } else if (persistedObj.theme_name && persistedObj.theme_name !== 'AE_Firefly') {
+                    // If the persisted theme differs from the global default, assume
+                    // it was a prior user choice (backcompat for older installs).
+                    persistedHasUserTheme = true;
+                }
+            }
+        }
+
+        if (scfg && typeof scfg === 'object' && !persistedHasUserTheme) {
+            // Accept common keys for theme name so site authors have flexibility.
+            const themeName = scfg.theme_name ?? scfg.theme ?? scfg.themeName ?? scfg.site_theme;
+            if (themeName) ae_loc_init['theme_name'] = themeName;
             if (scfg.theme_mode && (scfg.theme_mode === 'light' || scfg.theme_mode === 'dark'))
                 ae_loc_init['theme_mode'] = scfg.theme_mode;
         }