From aef5666d4d95a82b2a29dc19bc0a6b11c122d6d6 Mon Sep 17 00:00:00 2001
From: Andreas Deininger <andreas@deininger.net>
Date: Tue, 7 Dec 2021 21:24:51 +0100
Subject: [PATCH] Preparations for using docsy theme as hugo module

---
 assets/bootstrap/scss/vendor/_rfs.scss | 228 +++++++++++++++++++++++++
 1 file changed, 228 insertions(+)
 create mode 100644 assets/bootstrap/scss/vendor/_rfs.scss

diff --git a/assets/bootstrap/scss/vendor/_rfs.scss b/assets/bootstrap/scss/vendor/_rfs.scss
new file mode 100644
index 0000000000..e453f441ee
--- /dev/null
+++ b/assets/bootstrap/scss/vendor/_rfs.scss
@@ -0,0 +1,228 @@
+// stylelint-disable property-blacklist, scss/dollar-variable-default
+
+// SCSS RFS mixin
+//
+// Automated responsive font sizes
+//
+// Licensed under MIT (https://github.com/twbs/rfs/blob/v8.x/LICENSE)
+
+// Configuration
+
+// Base font size
+$rfs-base-font-size: 1.25rem !default;
+$rfs-font-size-unit: rem !default;
+
+@if $rfs-font-size-unit != rem and $rfs-font-size-unit != px {
+  @error "`#{$rfs-font-size-unit}` is not a valid unit for $rfs-font-size-unit. Use `px` or `rem`.";
+}
+
+// Breakpoint at where font-size starts decreasing if screen width is smaller
+$rfs-breakpoint: 1200px !default;
+$rfs-breakpoint-unit: px !default;
+
+@if $rfs-breakpoint-unit != px and $rfs-breakpoint-unit != em and $rfs-breakpoint-unit != rem {
+  @error "`#{$rfs-breakpoint-unit}` is not a valid unit for $rfs-breakpoint-unit. Use `px`, `em` or `rem`.";
+}
+
+// Resize font size based on screen height and width
+$rfs-two-dimensional: false !default;
+
+// Factor of decrease
+$rfs-factor: 10 !default;
+
+@if type-of($rfs-factor) != "number" or $rfs-factor <= 1 {
+  @error "`#{$rfs-factor}` is not a valid  $rfs-factor, it must be greater than 1.";
+}
+
+// Generate enable or disable classes. Possibilities: false, "enable" or "disable"
+$rfs-class: false !default;
+
+// 1 rem = $rfs-rem-value px
+$rfs-rem-value: 16 !default;
+
+// Safari iframe resize bug: https://github.com/twbs/rfs/issues/14
+$rfs-safari-iframe-resize-bug-fix: false !default;
+
+// Disable RFS by setting $enable-responsive-font-sizes to false
+$enable-responsive-font-sizes: true !default;
+
+// Cache $rfs-base-font-size unit
+$rfs-base-font-size-unit: unit($rfs-base-font-size);
+
+@function divide($dividend, $divisor, $precision: 10) {
+  $sign: if($dividend > 0 and $divisor > 0 or $dividend < 0 and $divisor < 0, 1, -1);
+  $dividend: abs($dividend);
+  $divisor: abs($divisor);
+  @if $dividend == 0 {
+    @return 0;
+  }
+  @if $divisor == 0 {
+    @error "Cannot divide by 0";
+  }
+  $remainder: $dividend;
+  $result: 0;
+  $factor: 10;
+  @while ($remainder > 0 and $precision >= 0) {
+    $quotient: 0;
+    @while ($remainder >= $divisor) {
+      $remainder: $remainder - $divisor;
+      $quotient: $quotient + 1;
+    }
+    $result: $result * 10 + $quotient;
+    $factor: $factor * .1;
+    $remainder: $remainder * 10;
+    $precision: $precision - 1;
+    @if ($precision < 0 and $remainder >= $divisor * 5) {
+      $result: $result + 1;
+    }
+  }
+  $result: $result * $factor * $sign;
+  $dividend-unit: unit($dividend);
+  $divisor-unit: unit($divisor);
+  $unit-map: (
+    "px": 1px,
+    "rem": 1rem,
+    "em": 1em,
+    "%": 1%
+  );
+  @if ($dividend-unit != $divisor-unit and map-has-key($unit-map, $dividend-unit)) {
+    $result: $result * map-get($unit-map, $dividend-unit);
+  }
+  @return $result;
+}
+
+// Remove px-unit from $rfs-base-font-size for calculations
+@if $rfs-base-font-size-unit == "px" {
+  $rfs-base-font-size: divide($rfs-base-font-size, $rfs-base-font-size * 0 + 1);
+}
+@else if $rfs-base-font-size-unit == "rem" {
+  $rfs-base-font-size: divide($rfs-base-font-size, divide($rfs-base-font-size * 0 + 1, $rfs-rem-value));
+}
+
+// Cache $rfs-breakpoint unit to prevent multiple calls
+$rfs-breakpoint-unit-cache: unit($rfs-breakpoint);
+
+// Remove unit from $rfs-breakpoint for calculations
+@if $rfs-breakpoint-unit-cache == "px" {
+  $rfs-breakpoint: divide($rfs-breakpoint, $rfs-breakpoint * 0 + 1);
+}
+@else if $rfs-breakpoint-unit-cache == "rem" or $rfs-breakpoint-unit-cache == "em" {
+  $rfs-breakpoint: divide($rfs-breakpoint, divide($rfs-breakpoint * 0 + 1, $rfs-rem-value));
+}
+
+// Internal mixin that adds disable classes to the selector if needed.
+@mixin _rfs-disable-class {
+  @if $rfs-class == "disable" {
+    // Adding an extra class increases specificity, which prevents the media query to override the font size
+    &,
+    .disable-responsive-font-size &,
+    &.disable-responsive-font-size {
+      @content;
+    }
+  }
+  @else {
+    @content;
+  }
+}
+
+// Internal mixin that adds enable classes to the selector if needed.
+@mixin _rfs-enable-class {
+  @if $rfs-class == "enable" {
+    .enable-responsive-font-size &,
+    &.enable-responsive-font-size {
+      @content;
+    }
+  }
+  @else {
+    @content;
+  }
+}
+
+// Internal mixin used to determine which media query needs to be used
+@mixin _rfs-media-query($mq-value) {
+  @if $rfs-two-dimensional {
+    @media (max-width: #{$mq-value}), (max-height: #{$mq-value}) {
+      @content;
+    }
+  }
+  @else {
+    @media (max-width: #{$mq-value}) {
+      @content;
+    }
+  }
+}
+
+// Responsive font size mixin
+@mixin rfs($fs, $important: false) {
+  // Cache $fs unit
+  $fs-unit: if(type-of($fs) == "number", unit($fs), false);
+
+  // Add !important suffix if needed
+  $rfs-suffix: if($important, " !important", "");
+
+  // If $fs isn't a number (like inherit) or $fs has a unit (not px or rem, like 1.5em) or $ is 0, just print the value
+  @if not $fs-unit or $fs-unit != "" and $fs-unit != "px" and $fs-unit != "rem" or $fs == 0 {
+    font-size: #{$fs}#{$rfs-suffix};
+  }
+  @else {
+    // Remove unit from $fs for calculations
+    @if $fs-unit == "px" {
+      $fs: divide($fs, $fs * 0 + 1);
+    }
+    @else if $fs-unit == "rem" {
+      $fs: divide($fs, divide($fs * 0 + 1, $rfs-rem-value));
+    }
+
+    // Set default font size
+    $rfs-static: if($rfs-font-size-unit == rem, #{divide($fs, $rfs-rem-value)}rem, #{$fs}px);
+
+    // Only add the media query if the font size is bigger than the minimum font size
+    @if $fs <= $rfs-base-font-size or not $enable-responsive-font-sizes {
+      font-size: #{$rfs-static}#{$rfs-suffix};
+    }
+    @else {
+      // Calculate the minimum font size for $fs
+      $fs-min: $rfs-base-font-size + divide($fs - $rfs-base-font-size, $rfs-factor);
+
+      // Calculate difference between $fs and the minimum font size
+      $fs-diff: $fs - $fs-min;
+
+      // Base font-size formatting
+      $min-width: if($rfs-font-size-unit == rem, #{divide($fs-min, $rfs-rem-value)}rem, #{$fs-min}px);
+
+      // Use `vmin` if two-dimensional is enabled
+      $variable-unit: if($rfs-two-dimensional, vmin, vw);
+
+      // Calculate the variable width between 0 and $rfs-breakpoint
+      $variable-width: #{divide($fs-diff * 100, $rfs-breakpoint)}#{$variable-unit};
+
+      // Set the calculated font-size
+      $rfs-fluid: calc(#{$min-width} + #{$variable-width}) #{$rfs-suffix};
+
+      // Breakpoint formatting
+      $mq-value: if($rfs-breakpoint-unit == px, #{$rfs-breakpoint}px, #{divide($rfs-breakpoint, $rfs-rem-value)}#{$rfs-breakpoint-unit});
+
+      @include _rfs-disable-class {
+        font-size: #{$rfs-static}#{$rfs-suffix};
+      }
+
+      @include _rfs-media-query($mq-value) {
+        @include _rfs-enable-class {
+          font-size: $rfs-fluid;
+        }
+
+        // Include safari iframe resize fix if needed
+        min-width: if($rfs-safari-iframe-resize-bug-fix, (0 * 1vw), null);
+      }
+    }
+  }
+}
+
+// The font-size & responsive-font-size mixins use RFS to rescale the font size
+@mixin font-size($fs, $important: false) {
+  @include rfs($fs, $important);
+}
+
+@mixin responsive-font-size($fs, $important: false) {
+  @include rfs($fs, $important);
+}