diff --git a/app.py b/app.py
index 6a92774..ef6d4ba 100644
--- a/app.py
+++ b/app.py
@@ -39,6 +39,27 @@ MODEL_ARTIFACT_DIR = BASE_DIR / "artifacts" / MODEL_VERSION
 VIEW_OVERVIEW = "Przegląd"
 VIEW_DETAIL = "Szczegóły cylindra"
 VIEW_MODEL = "Model"
+PLOTLY_CONFIG = {"displayModeBar": False, "displaylogo": False}
+DIAGNOSTIC_COLUMN_DISPLAY = {
+    "engine_id": "Silnik",
+    "cylinder": "Cylinder",
+    "label": "Diagnoza",
+    "severity": "Nasilenie",
+    "raw_model_label": "Surowa diagnoza modelu",
+    "decision_source": "Źródło decyzji",
+    "label_confidence": "Wynik diagnozy",
+    "raw_model_confidence": "Surowy wynik diagnozy",
+    "label_margin": "Margines decyzji",
+    "severity_confidence": "Wynik oceny nasilenia",
+    "anomaly_score_mean_abs_mv": "Średnie odchylenie bezwzględne [mV]",
+    "anomaly_ratio_to_engine_median": "Odchylenie względem mediany silnika",
+    "ood_absolute_threshold_mv": "Bezwzględny próg anomalii [mV]",
+    "ood_ratio_threshold": "Względny próg anomalii",
+    "top_anomalous_frequencies_khz": "Anomalne częstotliwości [kHz]",
+    "missing_spectral_cells": "Brakujące pomiary widma",
+    "model_version": "Wersja modelu",
+    "model_artifact_sha256": "Suma SHA-256 artefaktu",
+}
 
 
 @dataclass(frozen=True)
@@ -83,7 +104,7 @@ def build_dependencies() -> AppDependencies:
                 "Artefakt modelu nie został załadowany. Aplikacja działa w bezpiecznym "
                 "trybie demonstracyjnym na zapisanych predykcjach."
             ),
-            model_version="demo-precomputed",
+            model_version="tryb-demonstracyjny",
         )
 
 
@@ -110,17 +131,40 @@ def _format_confidence(value: float | int | None) -> str:
     return f"{100 * float(value):.0f}%"
 
 
+def _diagnostics_for_display(frame: pd.DataFrame) -> pd.DataFrame:
+    display = frame.copy()
+    for column in ("label", "raw_model_label"):
+        if column in display:
+            display[column] = display[column].map(LABEL_DISPLAY).fillna(display[column])
+    if "severity" in display:
+        display["severity"] = (
+            display["severity"].map(SEVERITY_DISPLAY).fillna(display["severity"])
+        )
+    if "decision_source" in display:
+        display["decision_source"] = display["decision_source"].replace(
+            {
+                "classifier": "Klasyfikator spektralny",
+                "ood_override": "Reguła anomalii",
+            }
+        )
+    if "model_version" in display:
+        display["model_version"] = display["model_version"].replace(
+            {"demo-precomputed": "tryb demonstracyjny"}
+        )
+    return display.rename(columns=DIAGNOSTIC_COLUMN_DISPLAY)
+
+
 def _render_header(live_inference: bool) -> None:
-    mode = "LIVE INFERENCE" if live_inference else "DEMO FALLBACK"
+    mode = "MODEL AKTYWNY" if live_inference else "TRYB DEMONSTRACYJNY"
     st.markdown(
         f"""
         <div class="product-header">
           <div>
-            <div class="eyebrow">AESTEEL · DIESEL INJECTION DIAGNOSTICS</div>
-            <h1>ENGIN Diagnostic Console</h1>
+            <div class="eyebrow">AESTEEL · DIAGNOSTYKA WTRYSKU DIESEL</div>
+            <h1>Konsola diagnostyczna ENGIN</h1>
             <p>Diagnoza cylindra, nasilenie i następny krok.</p>
           </div>
-          <div class="runtime-badge">● {mode}<br><span>CPU · LEAKAGE-SAFE</span></div>
+          <div class="runtime-badge">● {mode}<br><span>CPU · DANE LOKALNE</span></div>
         </div>
         """,
         unsafe_allow_html=True,
@@ -134,7 +178,7 @@ def _render_summary(summary) -> None:
           <div><span>STATUS SILNIKA</span><strong>{html.escape(summary.status)}</strong></div>
           <div><span>NAJWYŻSZE NASILENIE</span><strong>{html.escape(summary.highest_severity_display)}</strong></div>
           <div><span>WYMAGA UWAGI</span><strong>{summary.attention} / {summary.cylinders}</strong></div>
-          <div><span>ŚR. SCORE MODELU</span><strong>{_format_confidence(summary.mean_confidence)}</strong></div>
+          <div><span>ŚR. WYNIK MODELU</span><strong>{_format_confidence(summary.mean_confidence)}</strong></div>
         </div>
         """,
         unsafe_allow_html=True,
@@ -171,24 +215,29 @@ def _render_cylinder_grid(analysis, session_key: str, view_key: str) -> None:
 
 
 def _render_engine_overview(analysis) -> None:
-    left, right = st.columns([1.45, 1.0], gap="large")
+    left, right = st.columns(2, gap="large")
     with left:
-        st.plotly_chart(engine_heatmap(analysis), width="stretch", key=f"heatmap_{analysis.engine_id}")
+        st.markdown("### Mapa odchyleń")
+        st.plotly_chart(
+            engine_heatmap(analysis),
+            width="stretch",
+            key=f"heatmap_{analysis.engine_id}",
+            config=PLOTLY_CONFIG,
+        )
     with right:
         st.markdown("### Priorytet kontroli")
         ranking = rank_cylinders(analysis).head(6).copy()
         ranking["Cylinder"] = ranking["cylinder"].map(lambda value: f"C{int(value):02d}")
         ranking["Diagnoza"] = ranking["label_display"]
         ranking["Nasilenie"] = ranking["severity_display"]
-        ranking["Score modelu"] = ranking["label_confidence"].map(_format_confidence)
+        ranking["Wynik modelu"] = ranking["label_confidence"].map(_format_confidence)
         ranking["Priorytet"] = ranking["priority_display"]
         st.dataframe(
-            ranking[["Cylinder", "Diagnoza", "Nasilenie", "Score modelu", "Priorytet"]],
+            ranking[["Cylinder", "Diagnoza", "Nasilenie", "Wynik modelu", "Priorytet"]],
             hide_index=True,
             width="stretch",
-            height=315,
+            height=360,
         )
-        st.caption("Priorytet: nasilenie → odchylenie → score modelu.")
 
 
 def _render_cylinder_detail(
@@ -209,8 +258,8 @@ def _render_cylinder_detail(
             <p>{html.escape(explanation.severity_display)}</p>
           </div>
           <div class="diagnosis-metrics">
-            <div><span>Score label</span><strong>{_format_confidence(explanation.confidence)}</strong></div>
-            <div><span>Score severity</span><strong>{_format_confidence(severity_confidence)}</strong></div>
+            <div><span>Wynik diagnozy</span><strong>{_format_confidence(explanation.confidence)}</strong></div>
+            <div><span>Wynik oceny nasilenia</span><strong>{_format_confidence(severity_confidence)}</strong></div>
             <div><span>Średnie odchylenie</span><strong>{explanation.anomaly_score:.1f} mV</strong></div>
           </div>
         </div>
@@ -225,6 +274,7 @@ def _render_cylinder_detail(
             f"spectrum_{analysis.engine_id}_"
             + "_".join(str(value) for value in comparison_cylinders)
         ),
+        config=PLOTLY_CONFIG,
     )
 
     st.markdown("#### Odchylenie cylindra głównego")
@@ -232,6 +282,7 @@ def _render_cylinder_detail(
         deviation_chart(analysis, cylinder),
         width="stretch",
         key=f"deviation_{analysis.engine_id}_{cylinder}",
+        config=PLOTLY_CONFIG,
     )
 
     why, next_step = st.columns(2, gap="large")
@@ -242,30 +293,37 @@ def _render_cylinder_detail(
         st.markdown("#### Następny krok")
         st.write(explanation.recommendation)
         source_label = (
-            "Reguła OOD"
+            "Reguła anomalii"
             if explanation.decision_source == "ood_override"
             else "Klasyfikator spektralny"
         )
-        st.caption(f"Źródło: {source_label} · score nie jest prawdopodobieństwem.")
+        st.caption(
+            f"Źródło: {source_label} · wynik modelu nie jest prawdopodobieństwem."
+        )
 
 
 def _render_technical(result: DiagnosisResult) -> None:
     st.markdown("### Walidacja i model")
     c1, c2, c3, c4 = st.columns(4)
-    c1.metric("Grouped Macro F1", "0.981")
-    c2.metric("Severity accuracy", "0.930")
-    c3.metric("Walidacyjne ML", "33.65 / 40")
+    c1.metric("Makro F1 (grupowe)", "0.981")
+    c2.metric("Trafność nasilenia", "0.930")
+    c3.metric("Punkty walidacyjne", "33.65 / 40")
     c4.metric("Testy", "38 / 38")
     st.caption(
-        "Grouped CV po engine_id · 5 seedów · Macro F1 przy 5% braków: 0.983 · CPU."
+        "Walidacja grupowa według silników · średnia z 5 uruchomień · "
+        "makro F1 przy 5% braków: 0.983 · CPU."
     )
     with st.expander("Pokaż dane diagnostyczne"):
-        st.dataframe(result.diagnostics, width="stretch", hide_index=True)
+        st.dataframe(
+            _diagnostics_for_display(result.diagnostics),
+            width="stretch",
+            hide_index=True,
+        )
 
 
 def render_app(dependencies: AppDependencies | None = None) -> None:
     st.set_page_config(
-        page_title="ENGIN Diagnostic Console",
+        page_title="Konsola diagnostyczna ENGIN",
         page_icon="⚙️",
         layout="wide",
         initial_sidebar_state="expanded",
@@ -284,7 +342,7 @@ def render_app(dependencies: AppDependencies | None = None) -> None:
         payload: bytes | None
         if source == "Dane demonstracyjne":
             payload = deps.demo_payload
-            st.success("Demo załadowane")
+            st.success("Dane demonstracyjne załadowane")
         else:
             uploaded = st.file_uploader("Plik pomiarowy CSV", type=["csv"])
             payload = uploaded.getvalue() if uploaded is not None else None
@@ -316,14 +374,14 @@ def render_app(dependencies: AppDependencies | None = None) -> None:
     with st.sidebar:
         engine_id = st.selectbox("Aktywny silnik", result.engine_ids)
         st.download_button(
-            "Pobierz predictions.csv",
+            "Pobierz wyniki (CSV)",
             data=result.submission.to_csv(index=False).encode("utf-8"),
             file_name="predictions.csv",
             mime="text/csv",
             width="stretch",
         )
         st.download_button(
-            "Pobierz diagnostykę",
+            "Pobierz dane diagnostyczne (CSV)",
             data=result.diagnostics.to_csv(index=False).encode("utf-8"),
             file_name="prediction_diagnostics.csv",
             mime="text/csv",
@@ -331,7 +389,8 @@ def render_app(dependencies: AppDependencies | None = None) -> None:
         )
         st.divider()
         st.caption(
-            f"Model {deps.model_version} · CPU inference · brak połączeń zewnętrznych"
+            f"Wersja modelu: {deps.model_version} · wnioskowanie na CPU · "
+            "bez połączeń zewnętrznych"
         )
 
     analysis = analyze_engine(result, str(engine_id))
diff --git a/assets/app.css b/assets/app.css
index 4307f41..df6231f 100644
--- a/assets/app.css
+++ b/assets/app.css
@@ -98,6 +98,22 @@
 [data-testid="stMetric"] { padding: .7rem; border: 1px solid var(--line); background: var(--panel); }
 [data-testid="stDataFrame"], [data-testid="stPlotlyChart"] { border: 1px solid var(--line); overflow: hidden; }
 
+/* Streamlit 1.62 has no interface locale setting, so localize its uploader chrome. */
+[data-testid="stFileUploaderDropzone"] button [data-testid="stMarkdownContainer"] { display: none; }
+[data-testid="stFileUploaderDropzone"] button::after { content: "Wybierz plik"; }
+[data-testid="stFileUploaderDropzoneInstructions"] > div { display: none; }
+[data-testid="stFileUploaderDropzoneInstructions"]::after {
+  content: "Maks. 10 MB na plik · CSV";
+  color: var(--muted);
+  font-size: .875rem;
+  white-space: nowrap;
+}
+[data-testid="stFileUploaderDropzone"] > div:not([data-testid]) > span { font-size: 0; }
+[data-testid="stFileUploaderDropzone"] > div:not([data-testid]) > span::after {
+  content: "Upuść plik tutaj";
+  font-size: .875rem;
+}
+
 @media (max-width: 1000px) {
   .product-header { flex-direction: column; }
   .diagnosis-card { grid-template-columns: 1fr; }
diff --git a/engin/charts.py b/engin/charts.py
index ee4fb98..3f2afb0 100644
--- a/engin/charts.py
+++ b/engin/charts.py
@@ -57,10 +57,9 @@ def engine_heatmap(analysis: EngineAnalysis) -> go.Figure:
             hovertemplate="Cylinder %{y}<br>%{x} kHz<br>Odchylenie %{z:.1f} mV<extra></extra>",
         )
     )
-    fig.update_layout(title="Mapa odchyleń")
     fig.update_yaxes(autorange="reversed", title="Cylinder")
     fig.update_xaxes(title="Częstotliwość [kHz]", dtick=2)
-    return _base_layout(fig, height=420)
+    return _base_layout(fig, height=360, margin_top=18, margin_bottom=42)
 
 
 def _cylinder_position(analysis: EngineAnalysis, cylinder: int) -> int:
diff --git a/tests/test_app_smoke.py b/tests/test_app_smoke.py
index 3b3b452..3cd15af 100644
--- a/tests/test_app_smoke.py
+++ b/tests/test_app_smoke.py
@@ -19,6 +19,31 @@ class StreamlitSmokeTests(unittest.TestCase):
         self.assertFalse(
             any(selector.label == "Cylinder główny" for selector in app.selectbox)
         )
+        rendered = "\n".join(markdown.value for markdown in app.markdown)
+        self.assertIn("Konsola diagnostyczna ENGIN", rendered)
+        for english_fragment in (
+            "Diagnostic Console",
+            "LIVE INFERENCE",
+            "DEMO FALLBACK",
+            "LEAKAGE-SAFE",
+            "Grouped Macro F1",
+            "Severity accuracy",
+        ):
+            self.assertNotIn(english_fragment, rendered)
+
+        app.segmented_control[0].set_value("Model").run()
+        self.assertEqual(
+            [metric.label for metric in app.metric],
+            [
+                "Makro F1 (grupowe)",
+                "Trafność nasilenia",
+                "Punkty walidacyjne",
+                "Testy",
+            ],
+        )
+        diagnostic_columns = set(app.dataframe[0].value.columns)
+        self.assertIn("Źródło decyzji", diagnostic_columns)
+        self.assertNotIn("decision_source", diagnostic_columns)
 
     def test_upload_mode_has_safe_empty_state(self) -> None:
         app = AppTest.from_file(str(ROOT / "app.py"), default_timeout=30).run()
diff --git a/tests/test_explainability.py b/tests/test_explainability.py
index 40e12b2..9791fab 100644
--- a/tests/test_explainability.py
+++ b/tests/test_explainability.py
@@ -63,7 +63,9 @@ class ExplainabilityTests(unittest.TestCase):
     def test_all_chart_factories_return_populated_figures(self) -> None:
         cylinder = int(self.analysis.measurements["cylinder"].iloc[0])
         compared = self.analysis.measurements["cylinder"].astype(int).head(4).tolist()
-        self.assertEqual(len(engine_heatmap(self.analysis).data), 1)
+        heatmap = engine_heatmap(self.analysis)
+        self.assertEqual(len(heatmap.data), 1)
+        self.assertEqual(heatmap.layout.height, 360)
         self.assertEqual(len(cylinder_spectrum(self.analysis, cylinder).data), 2)
         self.assertEqual(
             len(cylinder_spectrum(self.analysis, cylinder, compared).data),