Clean up reveal line logic

extensions/markdown/media/main.js

@@ -156,9 +156,9 @@
 			if (next) {
 				const betweenProgress = (offset - window.scrollY - previous.element.getBoundingClientRect().top) / (next.element.getBoundingClientRect().top - previous.element.getBoundingClientRect().top);
 				const line = previous.line + betweenProgress * (next.line - previous.line);
-				return (0 <= line) ? line : 0;
+				return Math.max(line, 0);
 			} else {
-				return (0 <= previous.line) ? previous.line : 0;
+				return Math.max(previous.line, 0);
 			}
 		}
 		return null;