Update src/simplify-calculation.js

Co-authored-by: Bramus <[email protected]>

src/simplify-calculation.js

@@ -90,7 +90,7 @@ export function simplifyCalculation(root, info = {}) {
       if (root.value === 'e') {
         return new CSSUnitValue(Math.E, 'number');
       } else if (root.value === 'pi') {
-        return new CSSUnitValue(3.1415926535897932, 'number');
+        return new CSSUnitValue(Math.PI, 'number');
       }
     }
     // 4. Otherwise, return root.