[Tu Tran]

Hi,

1/ To to do that, please go to the file skin\frontend\default\sns_nova\css\theme-xxx.css, which is currently using on your site, add the code below:

.products-grid .item .item-inner .item-img .cart-wrap .out-of-stock {
  font-size: 116.7%;
  text-transform: none;
  position: relative;
  height: 32px;
  padding: 0 23px 0 23px;
  border: 1px solid #e5e5e5;
  background: #FFF;
  border-radius: 18px;
  text-align: center;
  display: inline-block;
  line-height: 32px;
  font-weight: bold;
}

to the end of the file.
2/ To solve this issue, please go to the file app\code\local\Sns\Producttabs\Block\List.php, find and replace the code

//$items[$product_obj->id] = $product_obj;

By:

$items[$product_obj->id] = $product_obj;

3/ This is not the single product, and normally there no add to cart button with the out of stock products. I have tried to check on my local, but don’t see that. So please check the config of this one again !

Thanks you,