Single product gallerry thumbnails size and orientation on right

I try this code to add, but nothing worked 🙁

@media only screen and (min-width: 990px) {

  .single-product-main-image {
      width: 55%; 
  }
  .single-product div.product .woocommerce-product-gallery .flex-viewport {
      margin-bottom: 20px;
      width: 70%;
      min-height: 312px;
  }
  .single-product div.product .woocommerce-product-gallery .flex-control-thumbs {
      float: right;
      position: relative;
      top: -484px;
  }
  .single-product div.product .woocommerce-product-gallery.woocommerce-product-gallery--columns-4 .flex-control-thumbs li {
      width: 100%;
      float: right;
      display: block;
      margin-right: 0;
      clear: right;
  }