Polish export preview readability

frontend/src/styles/app.css

@@ -1771,6 +1771,74 @@ button.entity-card {
   max-height: 38rem;
 }
 
+.export-preview-summary {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(7.5rem, 1fr));
+  gap: 0.55rem;
+  margin-top: 0.75rem;
+}
+
+.export-preview-summary-card {
+  display: grid;
+  gap: 0.14rem;
+  min-width: 0;
+  border: 1px solid var(--line);
+  border-radius: 8px;
+  padding: 0.62rem;
+  background: #ffffff;
+}
+
+.export-preview-summary-card span {
+  color: var(--muted);
+  font-size: 0.68rem;
+  font-weight: 800;
+  letter-spacing: 0.05em;
+  text-transform: uppercase;
+}
+
+.export-preview-summary-card strong {
+  overflow-wrap: anywhere;
+  font-size: 0.92rem;
+  line-height: 1.2;
+}
+
+.export-preview-json-shell {
+  min-width: 0;
+  margin-top: 0.75rem;
+  border: 1px solid var(--line);
+  border-radius: 8px;
+  overflow: hidden;
+  background: #0f172a;
+}
+
+.export-preview-json-toolbar {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.45rem;
+  justify-content: space-between;
+  border-bottom: 1px solid rgba(226, 232, 240, 0.18);
+  padding: 0.55rem 0.68rem;
+  color: #cbd5e1;
+  font-size: 0.78rem;
+  font-weight: 800;
+}
+
+.export-preview-json-body {
+  max-height: 32rem;
+  overflow: auto;
+}
+
+.export-preview-json-body .job-result {
+  max-height: none;
+  margin: 0;
+  border: 0;
+  border-radius: 0;
+  background: #0f172a;
+  color: #e2e8f0;
+  white-space: pre-wrap;
+  overflow-wrap: anywhere;
+}
+
 .map-toolbar {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));