diff --git a/poc4_active_source_20260714/src/agent_console/presentation.py b/poc4_active_source_20260714/src/agent_console/presentation.py
index 2ea8b72..41a2a0b 100644
--- a/poc4_active_source_20260714/src/agent_console/presentation.py
+++ b/poc4_active_source_20260714/src/agent_console/presentation.py
@@ -33,6 +33,17 @@ def apply_console_theme(st: Any, profile: AppProfile) -> None:
         input, textarea, [data-baseweb="select"] > div, [data-testid="stSidebar"] button {{
           background:#fff !important; border:1px solid var(--console-border) !important;
           border-radius:4px !important; box-shadow:none !important; }}
+        /* Streamlit JSON uses an independently styled code surface.  Keep the
+           MCP detail payload readable even when the browser/system prefers a
+           dark code theme. */
+        [data-testid="stJson"], [data-testid="stJson"] > div,
+        [data-testid="stJson"] .react-json-view, [data-testid="stJson"] pre {{
+          background:#f8fafc !important; color:var(--console-text) !important;
+          border-color:var(--console-border) !important; color-scheme:light !important; }}
+        [data-testid="stJson"] *, [data-testid="stJson"] pre *,
+        [data-testid="stJson"] code {{
+          background:transparent !important; color:var(--console-text) !important;
+          -webkit-text-fill-color:var(--console-text) !important; }}
         div[data-testid="stButton"] > button, div[data-testid="stFormSubmitButton"] > button {{
           border-radius:4px !important; box-shadow:none !important; }}
         div[data-testid="stButton"] > button[kind="primary"],