Png image make background color black in css ionic

I am using css with ionic . Using image in background but when i use image that maked background black.without image it looks fine.

ion-content {
    --background:  url("/assets/product_background.png") 0 0/100% 95% no-repeat;
--ion-background-color: linear-gradient(to bottom,  #1a1240 35%,#6528af 70%,#736eed 100%);

With Background image

without background image

ok… so whats your question?