There are ways to target different browsers in CSS with media queries or like this in a selectors body:
-webkit-[css property]
-khtml-[css property]
-moz-[css property]
-ms-[css property]
But I cannot find a way to manipulate solely the Samsung Internet browser (to fix a small design issue that doesn't occur on any other browser). What can I do?
These are vendor prefixes. They are not actually targeting individual browsers.
When you prefix a property with -webkit, for example, you're targeting all browsers which use WebKit as their main rendering engine, like:
So, there isn't a specific Samsung Internet prefix you can use.