style: refine product page CSS by adjusting image dimensions and layout properties

public/themes/dist_static/static/css/product.css

@@ -473,7 +473,6 @@ body.is-p-subnav .site-header {
   box-shadow: none;
 }
 .p-spec__tab-media {
-  width: 7.5rem;
   display: flex;
   align-items: center;
   justify-content: center;
@@ -481,6 +480,9 @@ body.is-p-subnav .site-header {
 }
 .p-spec__tab-media img {
   width: auto;
+  height: 6.25rem; /* 100px */
+  max-width: 4.5rem; /* 72px */
+  object-fit: contain;
   display: block;
 }
 .p-spec__tab-name {