[] lets you use `sin`, `cos`, `tan`, `asin`, `acos`, `atan` and `atan2` to be able to compute trigonometric relationships following the [CSS Values 4] specification. ```css /* becomes */ ``` ## ⚠️ About custom properties Given the dynamic nature of custom properties it's impossible to know what the variable value is, which means the plugin can't compute a final value for the stylesheet. Because of that, any usage that contains a `var` is skipped. ## Units [] lets you use different special units that are within the spec and computed at run time to be able to calculate the result of the trigonometric function. The following units are supported: * `pi`: Computes to `Math.PI` which is `3.141592653589793` * `e`: Computes to `Math.E` which is `2.718281828459045` * `infinity`, `-infinity`: Compute to `Infinity` and `-Infinity` respectively. Note that the usage is case insensitive so `InFiNiTy` is a valid value. Some calculations (such as `sin(-infinity)`) might return `NaN` as per the spec. Given that `NaN` can't be replaced with a value that's useful to CSS it is left as is, as the result will be effectively ignored by the browser. ## Options ### preserve The `preserve` option determines whether the original notation is preserved. By default, it is not preserved. ```js ({ preserve: true }) ``` ```css /* becomes */ ``` [CSS Values 4]: