bug fixed

src/features/product/ui/Product.tsx

@@ -81,16 +81,18 @@ const ProductDetail = () => {
       ? 0
       : Number(String(quantity).replace(',', '.'));
 
-  /* ---------------- HELPERS ---------------- */
   const clampQuantity = (value: number) => {
     if (isNaN(value)) return MIN_QTY;
 
-    let safe = Math.max(value, MIN_QTY);
-    safe = Math.min(safe);
+    let safe = value;
+
+    if (isGram) {
+      safe = Math.max(value, MIN_QTY);
+      safe = Math.ceil(safe / STEP) * STEP;
+    }
 
     return safe;
   };
-
   const getQuantityMessage = (qty: number, measurement: string | null) => {
     if (!measurement) return `${qty} dona`;
     return `${qty} ${measurement}`;