I have two variables for footer-height: $footer-height-mobile and $footer-height-desktop

how can I simplify this code with a SCSS @function called "footer-height" that returns the appropriate footer height depending on the screen size

```
$header-height: 72px;
$title-min-height: 89px;
$grid-header-height: 135px;
$footer-height-desktop: 162px;
$footer-height-mobile: 440px;

.styles {
  min-height: calc(100vh - #{$header-height} - #{$title-min-height} - #{$grid-header-height} - #{$footer-height-mobile});

  @media (var-in-desktop) {
    min-height: calc(100vh - #{$header-height} - #{$title-min-height} - #{$grid-header-height} - #{$footer-height-desktop});    
  }
}
```