Description : Purpose and example of `@function` in SASS.
Answer :
The `@function` directive inSASS is used to create custom functions that perform calculations and return values to be used in your stylesheets. For example,`@function calculate-rem($px) { @return $px / 16px + rem; }` defines a function to convert pixel values to rem units. You can then use `font-size: calculate-rem(24px);` to apply the calculated value.