Have you tried to add pb=0 url parameter to your theme preview urls?See https://community.shopify.com/c/Technical-Q-A/how-to-remove-preview-bar/m-p/1023134/highlight/true#M43968 

Yep, since Shopify depreciated SCSS, this solution does not work anymore.You can try solution from this thread:https://community.shopify.com/c/Technical-Q-A/Tool-to-minify-css-liquid/m-p/1122310 also, looks like Shopify will support minification out ...

If your situation is similar to the starting topic, then you do not need anything custom, simply ask Shopify support to enable unit prices in your shop (this is by default enabled for France and Germany, but can be enabled for shops based elsewhere u...