diff --git a/src/workflow/WorkflowPage.tsx b/src/workflow/WorkflowPage.tsx
index 726713a..51915c4 100644
--- a/src/workflow/WorkflowPage.tsx
+++ b/src/workflow/WorkflowPage.tsx
@@ -49,6 +49,12 @@ import { persistentStorage } from "@/lib/storage";
 import type { Template } from "@/types/template";
 import type { NodeTypeDefinition } from "@/workflow/types/node-defs";
 import { getOutputItemType } from "./lib/outputDisplay";
+import {
+  aggregateWorkflowCostPreviews,
+  formatWorkflowCost,
+  getWorkflowNodeCostPreview,
+  hasWorkflowCostDiscount,
+} from "./lib/cost-preview";
 
 type ModelSyncStatus =
   | "idle"
@@ -1156,6 +1162,28 @@ export function WorkflowPage() {
   const modelsError = useModelsStore((s) => s.error);
   const fetchModels = useModelsStore((s) => s.fetchModels);
 
+  const estimatedWorkflowCost = useMemo(() => {
+    const modelById = new Map(
+      desktopModels.map((model) => [model.model_id, model]),
+    );
+    const baseEstimate = aggregateWorkflowCostPreviews(
+      nodes.map((node) =>
+        getWorkflowNodeCostPreview({
+          nodeType: node.data?.nodeType,
+          params: node.data?.params,
+          model: modelById.get(String(node.data?.params?.modelId ?? "")),
+        }),
+      ),
+    );
+    if (!baseEstimate) return null;
+    const multiplier = Math.max(1, Math.floor(Number(runCount) || 1));
+    if (multiplier === 1) return baseEstimate;
+    return {
+      price: baseEstimate.price * multiplier,
+      discountedPrice: baseEstimate.discountedPrice * multiplier,
+    };
+  }, [desktopModels, nodes, runCount]);
+
   const syncModels = useCallback(async () => {
     if (!apiKey) {
       setModelSyncStatus("no-key");
@@ -1811,6 +1839,43 @@ export function WorkflowPage() {
 
           {/* Right: Run controls */}
           <div className="flex items-center gap-1.5" data-guide="run-controls">
+            {estimatedWorkflowCost && (
+              <Tooltip delayDuration={0}>
+                <TooltipTrigger asChild>
+                  <span className="h-7 inline-flex items-center gap-1.5 rounded-lg border border-emerald-500/20 bg-emerald-500/10 px-2 text-[11px] font-semibold text-emerald-700 dark:text-emerald-300 whitespace-nowrap">
+                    <span>{t("workflow.totalEstimate", "Total Est.")}</span>
+                    {hasWorkflowCostDiscount(estimatedWorkflowCost) ? (
+                      <span className="inline-flex items-baseline gap-1">
+                        <span className="line-through opacity-60">
+                          ${formatWorkflowCost(estimatedWorkflowCost.price)}
+                        </span>
+                        <span>
+                          $
+                          {formatWorkflowCost(
+                            estimatedWorkflowCost.discountedPrice,
+                          )}
+                        </span>
+                      </span>
+                    ) : (
+                      <span>
+                        ${formatWorkflowCost(estimatedWorkflowCost.price)}
+                      </span>
+                    )}
+                    {runCount > 1 && (
+                      <span className="rounded-full border border-emerald-500/20 bg-emerald-500/10 px-1 text-[10px]">
+                        ×{runCount}
+                      </span>
+                    )}
+                  </span>
+                </TooltipTrigger>
+                <TooltipContent side="bottom" className="max-w-[260px]">
+                  {t(
+                    "workflow.costEstimateHint",
+                    "Estimated base price before running. Actual API cost may vary with inputs.",
+                  )}
+                </TooltipContent>
+              </Tooltip>
+            )}
             <div className="flex items-center rounded-lg overflow-hidden shadow-sm">
               {/* Run button — disabled in browser (no execution API) */}
               <Tooltip delayDuration={0}>
diff --git a/src/workflow/components/canvas/WorkflowCanvas.tsx b/src/workflow/components/canvas/WorkflowCanvas.tsx
index af0a410..fd00064 100644
--- a/src/workflow/components/canvas/WorkflowCanvas.tsx
+++ b/src/workflow/components/canvas/WorkflowCanvas.tsx
@@ -2635,14 +2635,14 @@ export function WorkflowCanvas({ nodeDefs = [] }: WorkflowCanvasProps) {
           deleteKeyCode={null}
           minZoom={0.05}
           maxZoom={2.5}
-          className="bg-background"
+          className="bg-slate-100 dark:bg-[#07111f]"
         >
           {showGrid && (
             <Background
               variant={BackgroundVariant.Lines}
               gap={20}
               lineWidth={1}
-              color="hsl(var(--border))"
+              color="hsl(var(--muted-foreground) / 0.2)"
             />
           )}
         </ReactFlow>
diff --git a/src/workflow/components/canvas/custom-node/CustomNode.tsx b/src/workflow/components/canvas/custom-node/CustomNode.tsx
index ab5e75d..ef6dfcf 100644
--- a/src/workflow/components/canvas/custom-node/CustomNode.tsx
+++ b/src/workflow/components/canvas/custom-node/CustomNode.tsx
@@ -30,6 +30,11 @@ import { workflowClient } from "@/api/client";
 import { useModelsStore } from "@/stores/modelsStore";
 import { getFormFieldsFromModel } from "@/lib/schemaToForm";
 import { formFieldsToModelParamSchema } from "../../../lib/model-converter";
+import {
+  formatWorkflowCost,
+  getWorkflowNodeCostPreview,
+  hasWorkflowCostDiscount,
+} from "../../../lib/cost-preview";
 import type { NodeStatus } from "@/workflow/types/execution";
 import type { WaveSpeedModel } from "@/workflow/types/node-defs";
 import type { FormFieldConfig } from "@/lib/schemaToForm";
@@ -242,6 +247,15 @@ function CustomNodeComponent({
   const isAITask = data.nodeType === "ai-task/run";
   const currentModelId = String(data.params?.modelId ?? "").trim();
   const currentModel = useModelsStore((s) => s.getModelById(currentModelId));
+  const costPreview = useMemo(
+    () =>
+      getWorkflowNodeCostPreview({
+        nodeType: data.nodeType,
+        params: data.params,
+        model: currentModel,
+      }),
+    [data.nodeType, data.params, currentModel],
+  );
 
   const schema = useMemo(() => {
     if (isAITask && currentModel) {
@@ -850,7 +864,8 @@ function CustomNodeComponent({
         ref={nodeRef}
         className={`
           relative rounded-xl
-          bg-[hsl(var(--card))] text-[hsl(var(--card-foreground))]
+          bg-white text-[hsl(var(--card-foreground))]
+          dark:bg-slate-800
           border-2
           ${resizing ? "" : "transition-all duration-300"}
           ${running ? (isInsideIterator ? "border-blue-500 animate-pulse-subtle" : "border-blue-500 animate-pulse-subtle") : ""}
@@ -858,7 +873,7 @@ function CustomNodeComponent({
           ${!running && !selected && status === "confirmed" ? "border-green-500/70" : ""}
           ${!running && !selected && status === "unconfirmed" ? "border-orange-500/70" : ""}
           ${!running && !selected && status === "error" ? "border-red-500/70" : ""}
-          ${!running && !selected && status === "idle" ? (hovered ? "border-[hsl(var(--border))] shadow-lg" : "border-[hsl(var(--border))] shadow-md") : ""}
+          ${!running && !selected && status === "idle" ? (hovered ? "border-slate-300 shadow-lg dark:border-slate-500 dark:shadow-[0_0_0_1px_rgba(148,163,184,.16),0_16px_36px_rgba(0,0,0,.45)]" : "border-slate-200 shadow-md dark:border-slate-600/80 dark:shadow-[0_0_0_1px_rgba(148,163,184,.10),0_12px_28px_rgba(0,0,0,.38)]") : ""}
           ${isInsideIterator && !running && !selected && status === "idle" ? "ring-1 ring-blue-500/20" : ""}
         `}
         style={{ width: savedWidth, minHeight: savedHeight, fontSize: 13 }}
@@ -905,12 +920,42 @@ function CustomNodeComponent({
               <NodeIcon className="w-3.5 h-3.5 text-primary" />
             </div>
           )}
-          <span className="font-semibold text-[13px] truncate">
+          <span className="font-semibold text-[13px] truncate min-w-0 flex-1">
             {nodeLabel}
           </span>
           <span className="text-[10px] text-[hsl(var(--muted-foreground))] opacity-50 font-mono flex-shrink-0">
             {shortId}
           </span>
+          {costPreview && (
+            <Tooltip delayDuration={0}>
+              <TooltipTrigger asChild>
+                <span className="nodrag nopan flex-shrink-0 inline-flex items-center gap-1 rounded-full border border-emerald-500/25 bg-emerald-500/10 px-1.5 py-0.5 text-[10px] font-semibold text-emerald-700 dark:text-emerald-300">
+                  <span>{t("workflow.estimated", "Est.")}</span>
+                  {hasWorkflowCostDiscount(costPreview) ? (
+                    <span className="inline-flex items-baseline gap-1">
+                      <span className="line-through opacity-60">
+                        ${formatWorkflowCost(costPreview.price)}
+                      </span>
+                      <span>
+                        ${formatWorkflowCost(costPreview.discountedPrice)}
+                      </span>
+                    </span>
+                  ) : (
+                    <span>${formatWorkflowCost(costPreview.price)}</span>
+                  )}
+                </span>
+              </TooltipTrigger>
+              <TooltipContent side="top" className="max-w-[240px]">
+                {t(
+                  "workflow.costEstimateHint",
+                  "Estimated base price before running. Actual API cost may vary with inputs.",
+                )}
+                {costPreview.runCount > 1
+                  ? ` ${t("workflow.runCount", "Run Count")}: ${costPreview.runCount}`
+                  : ""}
+              </TooltipContent>
+            </Tooltip>
+          )}
         </div>
         {/* ── Running status bar ── */}
         {running && (
diff --git a/src/workflow/lib/cost-preview.ts b/src/workflow/lib/cost-preview.ts
new file mode 100644
index 0000000..11f21d3
--- /dev/null
+++ b/src/workflow/lib/cost-preview.ts
@@ -0,0 +1,63 @@
+import { applyDiscount, getModelDiscountRate } from "@/lib/pricing";
+import type { PriceDisplay } from "@/lib/pricing";
+import type { Model } from "@/types/model";
+
+export interface WorkflowCostPreview extends PriceDisplay {
+  runCount: number;
+}
+
+function readRunCount(params?: Record<string, unknown>): number {
+  const raw = Number(params?.__runCount ?? 1);
+  if (!Number.isFinite(raw)) return 1;
+  return Math.max(1, Math.floor(raw));
+}
+
+export function getWorkflowNodeCostPreview({
+  nodeType,
+  params,
+  model,
+}: {
+  nodeType?: string;
+  params?: Record<string, unknown>;
+  model?: Model;
+}): WorkflowCostPreview | null {
+  if (nodeType !== "ai-task/run" || !model) return null;
+
+  const basePrice = Number(model.base_price ?? 0);
+  if (!Number.isFinite(basePrice) || basePrice <= 0) return null;
+
+  const runCount = readRunCount(params);
+  const display = applyDiscount(
+    basePrice * runCount,
+    getModelDiscountRate(model),
+  );
+  return { ...display, runCount };
+}
+
+export function aggregateWorkflowCostPreviews(
+  previews: Array<WorkflowCostPreview | null | undefined>,
+): PriceDisplay | null {
+  const valid = previews.filter(
+    (preview): preview is WorkflowCostPreview => !!preview,
+  );
+  if (valid.length === 0) return null;
+  return valid.reduce<PriceDisplay>(
+    (sum, preview) => ({
+      price: sum.price + preview.price,
+      discountedPrice: sum.discountedPrice + preview.discountedPrice,
+    }),
+    { price: 0, discountedPrice: 0 },
+  );
+}
+
+export function hasWorkflowCostDiscount(price: PriceDisplay): boolean {
+  return price.discountedPrice > 0 && price.discountedPrice < price.price;
+}
+
+export function formatWorkflowCost(value: number): string {
+  if (!Number.isFinite(value)) return "0.0000";
+  const normalized = Math.max(0, value);
+  if (normalized >= 1) return normalized.toFixed(2);
+  if (normalized >= 0.01) return normalized.toFixed(3);
+  return normalized.toFixed(4);
+}