diff --git a/backend/internal/service/v1.go b/backend/internal/service/v1.go
index c464b29..4e194b3 100644
--- a/backend/internal/service/v1.go
+++ b/backend/internal/service/v1.go
@@ -1893,7 +1893,7 @@ func (s *V1Service) generateCustomVideo(ctx context.Context, eventID string, mod
 	if len(active) == 0 {
 		return nil, "", ErrNoProviderAccount
 	}
-	size := upstreamSize(aspectRatio, resolution)
+	size := upstreamVideoSize(aspectRatio, resolution)
 	var lastErr error
 	var videoURL string
 	busy := 0
@@ -1974,6 +1974,38 @@ func upstreamSize(aspectRatio, resolution string) string {
 	return fmt.Sprintf("%dx%d", base*w/h, base)
 }
 
+// upstreamVideoSize maps our (ratio, resolution) to a "WxH" size for video
+// upstreams. Video "Np" tiers set the SHORT edge in pixels (like grok:
+// 720p 1:1 → 720x720, 720p 16:9 → 1280x720); 2K/4K fall back to the
+// long-edge mapping shared with images.
+func upstreamVideoSize(aspectRatio, resolution string) string {
+	short := 0
+	switch res := strings.ToLower(strings.TrimSpace(resolution)); res {
+	case "540p":
+		short = 540
+	case "720p", "":
+		short = 720
+	case "1080p":
+		short = 1080
+	}
+	if short == 0 {
+		return upstreamSize(aspectRatio, resolution)
+	}
+	w, h := 1, 1
+	parts := strings.Split(strings.ReplaceAll(strings.TrimSpace(aspectRatio), "x", ":"), ":")
+	if len(parts) == 2 {
+		if a, e1 := strconv.Atoi(strings.TrimSpace(parts[0])); e1 == nil && a > 0 {
+			if b, e2 := strconv.Atoi(strings.TrimSpace(parts[1])); e2 == nil && b > 0 {
+				w, h = a, b
+			}
+		}
+	}
+	if w >= h {
+		return fmt.Sprintf("%dx%d", short*w/h, short)
+	}
+	return fmt.Sprintf("%dx%d", short, short*h/w)
+}
+
 // upstreamQuality maps a resolution tier to the OpenAI quality enum.
 func upstreamQuality(resolution string) string {
 	switch strings.ToUpper(strings.TrimSpace(resolution)) {
diff --git a/frontend/src/views/PlaygroundView.vue b/frontend/src/views/PlaygroundView.vue
index d0ce0f5..816f583 100644
--- a/frontend/src/views/PlaygroundView.vue
+++ b/frontend/src/views/PlaygroundView.vue
@@ -303,7 +303,13 @@ async function copyImage(url) {
 const count = ref(1)
 const batchCount = computed(() => (mode.value === 'image' ? Math.max(1, Math.min(4, count.value)) : 1))
 
+// Guard against accidental double-clicks: a second run() within 600ms is
+// ignored (each click otherwise fires an independent, charged generation).
+let lastRunAt = 0
 async function run() {
+  const now = Date.now()
+  if (now - lastRunAt < 600) return
+  lastRunAt = now
   if (!modelId.value) { error.value = '请选择模型'; return }
   if (!prompt.value.trim()) { error.value = '请输入提示词'; return }
   if (refsRequired.value && refImages.value.length < 1) {