Styling Quantity block

Site URL: https://bramasoleatserenedigital.squarespace.com/

Hi! 

I am currently trying to customize the "quantity block" on my site store and tried using this code: 

/* product block quantity */
.product-block .productDetails .product-quantity-input input {
    border-radius: 10px;
    background: red;
}

but it is not working. Can anyone help?

I also am trying to add a border and round my product images but it is only applying to two sides? 

#1. Use this CSS code

.product-quantity-input input[type="number"] {
    background-color: red;
    border-radius: 30px;
}

#2. Can you take a screenshot of your problem?