Leveraging Sass Functions and Conditionals in Next.js

Offer examples of using Sass functions and conditions to calculate styles dynamically within a Next.js application, such as a function to create a responsive font-size scale.
// Install necessary packages
// npm install --save sass
// npm install --save @zeit/next-sass

// Create Sass function in your styles.scss
@function calculate-responsive-size($minSize, $maxSize) {
  $sizes: (
    320px: $minSize, // Mobile
    1280px: $maxSize // Desktop
  $result: ();
  @each $breakpoint, $size in $sizes {
    $result: map-merge((#{$breakpoint}: $size), $result);
  @return $result;

// Implement a Sass conditional mixin
@mixin responsive-font-size($property, $minSize, $maxSize) {
  $responsiveSizes: calculate-responsive-size($minSize, $maxSize);
  @each $breakpoint, $size in $responsiveSizes {
    @media (min-width: $breakpoint) {
      #{$property}: $size;

// Usage in an element class
.element {
  @include responsive-font-size('font-size', 1rem, 2rem);
This code snippet includes an installation command for sass and @zeit/next-sass packages. It creates a Sass function calculate-responsive-size which calculates the font sizes for mobile and desktop. Then, it sets up a mixin responsive-font-size which applies these sizes using media queries. Lastly, it shows how to use the mixin in a .element class to set responsive font-size.