Rem

Introduction

Sass functions and mixins to use rem units.

Installing

npm install @unsass/rem

Usage

@use "@unsass/rem";

.foo {
    font-size: rem.convert(16px);
}

Configuration

@use "@unsass/rem" with (
    $baseline: 10px
);

Options

Variable	Default	Description
$baseline	16px	Sets baseline reference. Only in px.

Top-level config override

If variables are already configured on top-level using @use ... with, by another dependency for example, you can't use this solution anymore, because the module can only be setup once, this is a Sass restriction with Module System, but another solution exist for override the main configuration, with a mixin!

See official documentation about override configuration with mixins.

Mixin	Description
config($baseline)	Override top-level with configuration.

Configuration rule with rem.config()

The following Sass will configure new parameters:

@use "@unsass/rem";

@include rem.config(10px);

API

Sass functions

Function	Description
convert($values...)	Convert px unit to rem.

Convert with rem.convert()

The following Sass...

@use "@unsass/rem";

.foo {
    font-size: rem.convert(16px); // Single value.
    margin: rem.convert(20px 30px); // Multiple values.
    border: rem.convert(1px solid darkcyan); // Multiple mixed values.
    box-shadow: rem.convert(0 0 10px 5px rgba(darkcyan, 0.75), inset 0 0 10px 5px rgba(darkcyan, 0.75)); // Comma-separated values.
}

...will produce the following CSS...

.foo {
    font-size: 1rem;
    margin: 1.25rem 1.875rem;
    border: 0.0625rem solid darkcyan;
    box-shadow: 0 0 0.625rem 0.3125rem rgba(0, 139, 139, 0.75), inset 0 0 0.625rem 0.3125rem rgba(0, 139, 139, 0.75);
}

Sass mixins

Mixin	Description
baseline($important)	Sets declaration with font-size property, with optional !important.
declaration($property, $value, $important)	Sets declaration with conversion of px unit to rem, with optional !important.

Convert declaration with rem.declaration()

The following Sass...

@use "@unsass/rem";

.foo {
    @include rem.declaration(font-size, 16px); // Single value.
    @include rem.declaration(margin, 20px 30px); // Multiple values.
    @include rem.declaration(border, 1px solid darkcyan); // Multiple mixed values.
    @include rem.declaration(box-shadow, 0 0 10px 5px rgba(darkcyan, 0.75), inset 0 0 10px 5px rgba(darkcyan, 0.75)); // Comma-separated values.
}

...will produce the following CSS...

.foo {
    font-size: 1rem;
    margin: 1.25rem 1.875rem;
    border: 0.0625rem solid darkcyan;
    box-shadow: 0 0 0.625rem 0.3125rem rgba(0, 139, 139, 0.75), inset 0 0 0.625rem 0.3125rem rgba(0, 139, 139, 0.75);
}

Baseline declaration with rem.baseline()

The following Sass...

@use "@unsass/rem";

html,
body {
    @include rem.baseline;
}

...will produce the following CSS...

html,
body {
    font-size: 100%
}