How to add modify SKU section on product page of Craft theme

[Monsoonzone]

Hi all,

I am using the Craft theme, and will like to use SKU section to show my books ISBN number.

But the problem is that while the number is showing, there is no title in front of it showing that it is ISBN number.

Is is possible to add a title in front showing "ISBN: " (with bold) when the SKU is not blank, but wont show anything if the SKU is blank?

Update: here is my website link
https://mzbooks.shop/products/%E9%9B%B6%E7%9A%84%E4%BB%A3%E5%83%B9-%E4%B8%AD%E5%9C%8B%E5%9C%A8%E6%96...

Thank you.

[Dan-From-Ryviu]

Could you share the link to your product page? 

[Monsoonzone]

Sorry I added the link edi, thank you.

[Dan-From-Ryviu]

Please add this code to Custom CSS in Online STore > THemes > Customize > Theme settings 

.product .product__sku:before {
    content: 'ISBN: ';
    font-weight: 700;
}

[suyash1]

@Monsoonzone please add this css to the very end of your base.css file and check,
Shopify Admin -> Online Store ->Theme -> Edit code -> base.css

.product__sku:before {
    content: "ISBN : ";
    font-weight: bold;
}