1 files changed, 127 insertions, 0 deletions
diff --git a/scss/mixins/_breakpoints.scss b/scss/mixins/_breakpoints.scss
new file mode 100644
index 0000000..286be89
--- /dev/null
+++ b/scss/mixins/_breakpoints.scss
@@ -0,0 +1,127 @@
+// Breakpoint viewport sizes and media queries.
+//
+// Breakpoints are defined as a map of (name: minimum width), order from small to large:
+//
+//    (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px)
+//
+// The map defined in the `$grid-breakpoints` global variable is used as the `$breakpoints` argument by default.
+
+// Name of the next breakpoint, or null for the last breakpoint.
+//
+//    >> breakpoint-next(sm)
+//    md
+//    >> breakpoint-next(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px))
+//    md
+//    >> breakpoint-next(sm, $breakpoint-names: (xs sm md lg xl xxl))
+//    md
+@function breakpoint-next($name, $breakpoints: $grid-breakpoints, $breakpoint-names: map-keys($breakpoints)) {
+  $n: index($breakpoint-names, $name);
+  @if not $n {
+    @error "breakpoint `#{$name}` not found in `#{$breakpoints}`";
+  }
+  @return if($n < length($breakpoint-names), nth($breakpoint-names, $n + 1), null);
+}
+
+// Minimum breakpoint width. Null for the smallest (first) breakpoint.
+//
+//    >> breakpoint-min(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px))
+//    576px
+@function breakpoint-min($name, $breakpoints: $grid-breakpoints) {
+  $min: map-get($breakpoints, $name);
+  @return if($min != 0, $min, null);
+}
+
+// Maximum breakpoint width.
+// The maximum value is reduced by 0.02px to work around the limitations of
+// `min-` and `max-` prefixes and viewports with fractional widths.
+// See https://www.w3.org/TR/mediaqueries-4/#mq-min-max
+// Uses 0.02px rather than 0.01px to work around a current rounding bug in Safari.
+// See https://bugs.webkit.org/show_bug.cgi?id=178261
+//
+//    >> breakpoint-max(md, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px))
+//    767.98px
+@function breakpoint-max($name, $breakpoints: $grid-breakpoints) {
+  $max: map-get($breakpoints, $name);
+  @return if($max and $max > 0, $max - .02, null);
+}
+
+// Returns a blank string if smallest breakpoint, otherwise returns the name with a dash in front.
+// Useful for making responsive utilities.
+//
+//    >> breakpoint-infix(xs, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px))
+//    ""  (Returns a blank string)
+//    >> breakpoint-infix(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px, xxl: 1400px))
+//    "-sm"
+@function breakpoint-infix($name, $breakpoints: $grid-breakpoints) {
+  @return if(breakpoint-min($name, $breakpoints) == null, "", "-#{$name}");
+}
+
+// Media of at least the minimum breakpoint width. No query for the smallest breakpoint.
+// Makes the @content apply to the given breakpoint and wider.
+@mixin media-breakpoint-up($name, $breakpoints: $grid-breakpoints) {
+  $min: breakpoint-min($name, $breakpoints);
+  @if $min {
+    @media (min-width: $min) {
+      @content;
+    }
+  } @else {
+    @content;
+  }
+}
+
+// Media of at most the maximum breakpoint width. No query for the largest breakpoint.
+// Makes the @content apply to the given breakpoint and narrower.
+@mixin media-breakpoint-down($name, $breakpoints: $grid-breakpoints) {
+  $max: breakpoint-max($name, $breakpoints);
+  @if $max {
+    @media (max-width: $max) {
+      @content;
+    }
+  } @else {
+    @content;
+  }
+}
+
+// Media that spans multiple breakpoint widths.
+// Makes the @content apply between the min and max breakpoints
+@mixin media-breakpoint-between($lower, $upper, $breakpoints: $grid-breakpoints) {
+  $min: breakpoint-min($lower, $breakpoints);
+  $max: breakpoint-max($upper, $breakpoints);
+
+  @if $min != null and $max != null {
+    @media (min-width: $min) and (max-width: $max) {
+      @content;
+    }
+  } @else if $max == null {
+    @include media-breakpoint-up($lower, $breakpoints) {
+      @content;
+    }
+  } @else if $min == null {
+    @include media-breakpoint-down($upper, $breakpoints) {
+      @content;
+    }
+  }
+}
+
+// Media between the breakpoint's minimum and maximum widths.
+// No minimum for the smallest breakpoint, and no maximum for the largest one.
+// Makes the @content apply only to the given breakpoint, not viewports any wider or narrower.
+@mixin media-breakpoint-only($name, $breakpoints: $grid-breakpoints) {
+  $min:  breakpoint-min($name, $breakpoints);
+  $next: breakpoint-next($name, $breakpoints);
+  $max:  breakpoint-max($next, $breakpoints);
+
+  @if $min != null and $max != null {
+    @media (min-width: $min) and (max-width: $max) {
+      @content;
+    }
+  } @else if $max == null {
+    @include media-breakpoint-up($name, $breakpoints) {
+      @content;
+    }
+  } @else if $min == null {
+    @include media-breakpoint-down($next, $breakpoints) {
+      @content;
+    }
+  }
+}