Merge branch 'v4-dev' into dropdown-keyboard

43 files changed, 368 insertions, 357 deletions

diff --git a/scss/_breadcrumb.scss b/scss/_breadcrumb.scss
index 1a09bba20..2bc0e2086 100644
--- a/scss/_breadcrumb.scss
+++ b/scss/_breadcrumb.scss
@@ -1,6 +1,6 @@
 .breadcrumb {
   padding: $breadcrumb-padding-y $breadcrumb-padding-x;
-  margin-bottom: $spacer-y;
+  margin-bottom: 1rem;
   list-style: none;
   background-color: $breadcrumb-bg;
   @include border-radius($border-radius);
diff --git a/scss/_button-group.scss b/scss/_button-group.scss
index facecd37a..af74a55f1 100644
--- a/scss/_button-group.scss
+++ b/scss/_button-group.scss
@@ -99,8 +99,8 @@
 //
 
 .btn + .dropdown-toggle-split {
-  padding-right: $btn-padding-x * .75;
-  padding-left: $btn-padding-x * .75;
+  padding-right: $input-btn-padding-x * .75;
+  padding-left: $input-btn-padding-x * .75;
 
   &::after {
     margin-left: 0;
@@ -108,13 +108,13 @@
 }
 
 .btn-sm + .dropdown-toggle-split {
-  padding-right: $btn-padding-x-sm * .75;
-  padding-left: $btn-padding-x-sm * .75;
+  padding-right: $input-btn-padding-x-sm * .75;
+  padding-left: $input-btn-padding-x-sm * .75;
 }
 
 .btn-lg + .dropdown-toggle-split {
-  padding-right: $btn-padding-x-lg * .75;
-  padding-left: $btn-padding-x-lg * .75;
+  padding-right: $input-btn-padding-x-lg * .75;
+  padding-left: $input-btn-padding-x-lg * .75;
 }
 
 
diff --git a/scss/_buttons.scss b/scss/_buttons.scss
index e36ff0f1f..4a8ffcbe5 100644
--- a/scss/_buttons.scss
+++ b/scss/_buttons.scss
@@ -7,13 +7,12 @@
 .btn {
   display: inline-block;
   font-weight: $btn-font-weight;
-  line-height: $btn-line-height;
   text-align: center;
   white-space: nowrap;
   vertical-align: middle;
   user-select: none;
   border: $input-btn-border-width solid transparent;
-  @include button-size($btn-padding-y, $btn-padding-x, $font-size-base, $btn-border-radius);
+  @include button-size($input-btn-padding-y, $input-btn-padding-x, $font-size-base, $input-btn-line-height, $btn-border-radius);
   @include transition($btn-transition);
 
   // Share hover and focus styles
@@ -73,22 +72,22 @@ fieldset[disabled] a.btn {
 
 // Remove all backgrounds
 .btn-outline-primary {
-  @include button-outline-variant($btn-primary-bg);
+  @include button-outline-variant($btn-primary-bg, $btn-primary-color);
 }
 .btn-outline-secondary {
-  @include button-outline-variant($btn-secondary-border);
+  @include button-outline-variant($btn-secondary-border, $btn-secondary-color);
 }
 .btn-outline-info {
-  @include button-outline-variant($btn-info-bg);
+  @include button-outline-variant($btn-info-bg, $btn-info-color);
 }
 .btn-outline-success {
-  @include button-outline-variant($btn-success-bg);
+  @include button-outline-variant($btn-success-bg, $btn-success-color);
 }
 .btn-outline-warning {
-  @include button-outline-variant($btn-warning-bg);
+  @include button-outline-variant($btn-warning-bg, $btn-warning-color);
 }
 .btn-outline-danger {
-  @include button-outline-variant($btn-danger-bg);
+  @include button-outline-variant($btn-danger-bg, $btn-danger-color);
 }
 
 
@@ -137,12 +136,11 @@ fieldset[disabled] a.btn {
 //
 
 .btn-lg {
-  // line-height: ensure even-numbered height of button next to large input
-  @include button-size($btn-padding-y-lg, $btn-padding-x-lg, $font-size-lg, $btn-border-radius-lg);
+  @include button-size($input-btn-padding-y-lg, $input-btn-padding-x-lg, $font-size-lg, $line-height-lg, $btn-border-radius-lg);
 }
+
 .btn-sm {
-  // line-height: ensure proper height of button next to small input
-  @include button-size($btn-padding-y-sm, $btn-padding-x-sm, $font-size-sm, $btn-border-radius-sm);
+  @include button-size($input-btn-padding-y-sm, $input-btn-padding-x-sm, $font-size-sm, $line-height-sm, $btn-border-radius-sm);
 }
 
 
diff --git a/scss/_card.scss b/scss/_card.scss
index 9fe70e8cf..2c74c0c97 100644
--- a/scss/_card.scss
+++ b/scss/_card.scss
@@ -158,10 +158,6 @@
 }
 
 // Card image
-.card-img {
-  // margin: -1.325rem;
-  @include border-radius($card-border-radius-inner);
-}
 .card-img-overlay {
   position: absolute;
   top: 0;
@@ -171,13 +167,19 @@
   padding: $card-img-overlay-padding;
 }
 
-
+.card-img {
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
+  @include border-radius($card-border-radius-inner);
+}
 
 // Card image caps
 .card-img-top {
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
   @include border-top-radius($card-border-radius-inner);
 }
+
 .card-img-bottom {
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
   @include border-bottom-radius($card-border-radius-inner);
 }
 
@@ -188,17 +190,15 @@
   .card-deck {
     display: flex;
     flex-flow: row wrap;
+    margin-right: -$card-deck-margin;
+    margin-left: -$card-deck-margin;
 
     .card {
       display: flex;
       flex: 1 0 0;
       flex-direction: column;
-
-      // Selectively apply horizontal margins to cards to avoid doing the
-      // negative margin dance like our grid. This differs from the grid
-      // due to the use of margins as gutters instead of padding.
-      &:not(:first-child) { margin-left: $card-deck-margin; }
-      &:not(:last-child) { margin-right: $card-deck-margin; }
+      margin-right: $card-deck-margin;
+      margin-left: $card-deck-margin;
     }
   }
 }
diff --git a/scss/_custom-forms.scss b/scss/_custom-forms.scss
index 39f164822..d303c48d0 100644
--- a/scss/_custom-forms.scss
+++ b/scss/_custom-forms.scss
@@ -1,4 +1,4 @@
-// scss-lint:disable PropertyCount
+// scss-lint:disable PropertyCount, VendorPrefix
 
 // Embedded icons from Open Iconic.
 // Released under MIT and copyright 2014 Waybury.
@@ -229,7 +229,7 @@
   @include box-shadow($custom-file-box-shadow);
 
   @each $lang, $text in map-get($custom-file-text, placeholder) {
-    &:lang(#{$lang})::after {
+    &:lang(#{$lang}):empty::after {
       content: $text;
     }
   }
diff --git a/scss/_dropdown.scss b/scss/_dropdown.scss
index 1c2741a2e..090fdf1c1 100644
--- a/scss/_dropdown.scss
+++ b/scss/_dropdown.scss
@@ -18,9 +18,8 @@
     border-left: $caret-width solid transparent;
   }
 
-  // Prevent the focus on the dropdown toggle when closing dropdowns
-  &:focus {
-    outline: 0;
+  &:empty::after {
+    margin-left: 0;
   }
 }
 
@@ -66,7 +65,7 @@
 .dropdown-item {
   display: block;
   width: 100%; // For `<button>`s
-  padding: 3px $dropdown-item-padding-x;
+  padding: $dropdown-item-padding-y $dropdown-item-padding-x;
   clear: both;
   font-weight: $font-weight-normal;
   color: $dropdown-link-color;
diff --git a/scss/_forms.scss b/scss/_forms.scss
index 85180aa7f..11fa94a25 100644
--- a/scss/_forms.scss
+++ b/scss/_forms.scss
@@ -1,4 +1,4 @@
-// scss-lint:disable QualifyingElement
+// scss-lint:disable QualifyingElement, VendorPrefix
 
 //
 // Textual form controls
@@ -9,9 +9,9 @@
   width: 100%;
   // // Make inputs at least the height of their button counterpart (base line-height + padding + border)
   // height: $input-height;
-  padding: $input-padding-y $input-padding-x;
+  padding: $input-btn-padding-y $input-btn-padding-x;
   font-size: $font-size-base;
-  line-height: $input-line-height;
+  line-height: $input-btn-line-height;
   color: $input-color;
   background-color: $input-bg;
   // Reset unusual Firefox-on-Android default style; see https://github.com/necolas/normalize.css/issues/214.
@@ -95,20 +95,20 @@ select.form-control {
 // For use with horizontal and inline forms, when you need the label text to
 // align with the form controls.
 .col-form-label {
-  padding-top: calc(#{$input-padding-y} - #{$input-btn-border-width} * 2);
-  padding-bottom: calc(#{$input-padding-y} - #{$input-btn-border-width} * 2);
+  padding-top: calc(#{$input-btn-padding-y} - #{$input-btn-border-width} * 2);
+  padding-bottom: calc(#{$input-btn-padding-y} - #{$input-btn-border-width} * 2);
   margin-bottom: 0; // Override the `<label>` default
 }
 
 .col-form-label-lg {
-  padding-top: calc(#{$input-padding-y-lg} - #{$input-btn-border-width} * 2);
-  padding-bottom: calc(#{$input-padding-y-lg} - #{$input-btn-border-width} * 2);
+  padding-top: calc(#{$input-btn-padding-y-lg} - #{$input-btn-border-width} * 2);
+  padding-bottom: calc(#{$input-btn-padding-y-lg} - #{$input-btn-border-width} * 2);
   font-size: $font-size-lg;
 }
 
 .col-form-label-sm {
-  padding-top: calc(#{$input-padding-y-sm} - #{$input-btn-border-width} * 2);
-  padding-bottom: calc(#{$input-padding-y-sm} - #{$input-btn-border-width} * 2);
+  padding-top: calc(#{$input-btn-padding-y-sm} - #{$input-btn-border-width} * 2);
+  padding-bottom: calc(#{$input-btn-padding-y-sm} - #{$input-btn-border-width} * 2);
   font-size: $font-size-sm;
 }
 
@@ -120,8 +120,8 @@ select.form-control {
 // For use with horizontal and inline forms, when you need the legend text to
 // be the same size as regular labels, and to align with the form controls.
 .col-form-legend {
-  padding-top: $input-padding-y;
-  padding-bottom: $input-padding-y;
+  padding-top: $input-btn-padding-y;
+  padding-bottom: $input-btn-padding-y;
   margin-bottom: 0;
   font-size: $font-size-base;
 }
@@ -133,10 +133,10 @@ select.form-control {
 // horizontal form layout.
 
 .form-control-static {
-  padding-top: $input-padding-y;
-  padding-bottom: $input-padding-y;
+  padding-top: $input-btn-padding-y;
+  padding-bottom: $input-btn-padding-y;
   margin-bottom: 0; // match inputs if this class comes on inputs with default margins
-  line-height: $input-line-height;
+  line-height: $input-btn-line-height;
   border: solid transparent;
   border-width: $input-btn-border-width 0;
 
@@ -157,26 +157,30 @@ select.form-control {
 // issue documented in https://github.com/twbs/bootstrap/issues/15074.
 
 .form-control-sm {
-  padding: $input-padding-y-sm $input-padding-x-sm;
+  padding: $input-btn-padding-y-sm $input-btn-padding-x-sm;
   font-size: $font-size-sm;
+  line-height: $input-btn-line-height-sm;
   @include border-radius($input-border-radius-sm);
 }
 
 select.form-control-sm {
   &:not([size]):not([multiple]) {
-    height: $input-height-sm;
+    $select-border-width: ($border-width * 2);
+    height: calc(#{$input-height-sm} + #{$select-border-width});
   }
 }
 
 .form-control-lg {
-  padding: $input-padding-y-lg $input-padding-x-lg;
+  padding: $input-btn-padding-y-lg $input-btn-padding-x-lg;
   font-size: $font-size-lg;
+  line-height: $input-btn-line-height-lg;
   @include border-radius($input-border-radius-lg);
 }
 
 select.form-control-lg {
   &:not([size]):not([multiple]) {
-    height: $input-height-lg;
+    $select-border-width: ($border-width * 2);
+    height: calc(#{$input-height-lg} + #{$select-border-width});
   }
 }
 
@@ -253,7 +257,7 @@ select.form-control-lg {
 .form-control-success,
 .form-control-warning,
 .form-control-danger {
-  padding-right: ($input-padding-x * 3);
+  padding-right: ($input-btn-padding-x * 3);
   background-repeat: no-repeat;
   background-position: center right ($input-height / 4);
   background-size: ($input-height / 2) ($input-height / 2);
diff --git a/scss/_grid.scss b/scss/_grid.scss
index 8c7a9ee31..9ab9ae02b 100644
--- a/scss/_grid.scss
+++ b/scss/_grid.scss
@@ -11,11 +11,12 @@
 
 // Fluid container
 //
-// Utilizes the mixin meant for fixed width containers, but without any defined
-// width for fluid, full width layouts.
+// Utilizes the mixin meant for fixed width containers, but with 100% width for
+// fluid, full width layouts.
 
 @if $enable-grid-classes {
   .container-fluid {
+    width: 100%;
     @include make-container();
   }
 }
diff --git a/scss/_images.scss b/scss/_images.scss
index a8135a6c3..50c56108a 100644
--- a/scss/_images.scss
+++ b/scss/_images.scss
@@ -33,7 +33,7 @@
 }
 
 .figure-img {
-  margin-bottom: ($spacer-y / 2);
+  margin-bottom: ($spacer / 2);
   line-height: 1;
 }
 
diff --git a/scss/_input-group.scss b/scss/_input-group.scss
index 49cdf2830..0b668bff3 100644
--- a/scss/_input-group.scss
+++ b/scss/_input-group.scss
@@ -66,11 +66,11 @@
 //
 
 .input-group-addon {
-  padding: $input-padding-y $input-padding-x;
+  padding: $input-btn-padding-y $input-btn-padding-x;
   margin-bottom: 0; // Allow use of <label> elements by overriding our default margin-bottom
   font-size: $font-size-base; // Match inputs
   font-weight: $font-weight-normal;
-  line-height: $input-line-height;
+  line-height: $input-btn-line-height;
   color: $input-color;
   text-align: center;
   background-color: $input-group-addon-bg;
@@ -79,12 +79,13 @@
 
   // Sizing
   &.form-control-sm {
-    padding: $input-padding-y-sm $input-padding-x-sm;
+    padding: $input-btn-padding-y-sm $input-btn-padding-x-sm;
     font-size: $font-size-sm;
     @include border-radius($input-border-radius-sm);
   }
+
   &.form-control-lg {
-    padding: $input-padding-y-lg $input-padding-x-lg;
+    padding: $input-btn-padding-y-lg $input-btn-padding-x-lg;
     font-size: $font-size-lg;
     @include border-radius($input-border-radius-lg);
   }
diff --git a/scss/_jumbotron.scss b/scss/_jumbotron.scss
index b12d465d9..7966bba1e 100644
--- a/scss/_jumbotron.scss
+++ b/scss/_jumbotron.scss
@@ -9,10 +9,6 @@
   }
 }
 
-.jumbotron-hr {
-  border-top-color: darken($jumbotron-bg, 10%);
-}
-
 .jumbotron-fluid {
   padding-right: 0;
   padding-left: 0;
diff --git a/scss/_list-group.scss b/scss/_list-group.scss
index bb8a8d103..c4b5e2f92 100644
--- a/scss/_list-group.scss
+++ b/scss/_list-group.scss
@@ -42,9 +42,7 @@
 
 .list-group-item {
   position: relative;
-  display: flex;
-  flex-flow: row wrap;
-  align-items: center;
+  display: block;
   padding: $list-group-item-padding-y $list-group-item-padding-x;
   // Place the border on the list items and negative margin up for better styling
   margin-bottom: -$list-group-border-width;
diff --git a/scss/_mixins.scss b/scss/_mixins.scss
index da4738297..13aad2487 100644
--- a/scss/_mixins.scss
+++ b/scss/_mixins.scss
@@ -2,22 +2,6 @@
 //
 // Used in conjunction with global variables to enable certain theme features.
 
-@mixin box-shadow($shadow...) {
-  @if $enable-shadows {
-    box-shadow: $shadow;
-  }
-}
-
-@mixin transition($transition...) {
-  @if $enable-transitions {
-    @if length($transition) == 0 {
-      transition: $transition-base;
-    } @else {
-      transition: $transition;
-    }
-  }
-}
-
 // Utilities
 @import "mixins/breakpoints";
 @import "mixins/hover";
@@ -47,7 +31,9 @@
 // // Skins
 @import "mixins/background-variant";
 @import "mixins/border-radius";
+@import "mixins/box-shadow";
 @import "mixins/gradients";
+@import "mixins/transition";
 
 // // Layout
 @import "mixins/clearfix";
diff --git a/scss/_nav.scss b/scss/_nav.scss
index 7d902a7c0..2b6b2a7f3 100644
--- a/scss/_nav.scss
+++ b/scss/_nav.scss
@@ -13,7 +13,7 @@
 
 .nav-link {
   display: block;
-  padding: $nav-link-padding;
+  padding: $nav-link-padding-y $nav-link-padding-x;
 
   @include hover-focus {
     text-decoration: none;
@@ -26,7 +26,6 @@
   }
 }
 
-
 //
 // Tabs
 //
@@ -76,12 +75,12 @@
 .nav-pills {
   .nav-link {
     @include border-radius($nav-pills-border-radius);
-  }
 
-  .nav-link.active,
-  .nav-item.show .nav-link {
-    color: $nav-pills-active-link-color;
-    background-color: $nav-pills-active-link-bg;
+    &.active,
+    .show & {
+      color: $nav-pills-active-link-color;
+      background-color: $nav-pills-active-link-bg;
+    }
   }
 }
 
@@ -99,7 +98,8 @@
 
 .nav-justified {
   .nav-item {
-    flex: 1 1 100%;
+    flex-basis: 0;
+    flex-grow: 1;
     text-align: center;
   }
 }
diff --git a/scss/_navbar.scss b/scss/_navbar.scss
index 6c31017dc..854e7df12 100644
--- a/scss/_navbar.scss
+++ b/scss/_navbar.scss
@@ -18,11 +18,22 @@
 .navbar {
   position: relative;
   display: flex;
-  flex-direction: column;
+  flex-wrap: wrap; // allow us to do the line break for collapsing content
+  align-items: center;
+  justify-content: space-between; // space out brand from logo
   padding: $navbar-padding-y $navbar-padding-x;
 
-  @include media-breakpoint-down(nth(map-keys($grid-breakpoints), 1)) {
-    > .container {
+  // Because flex properties aren't inherited, we need to redeclare these first
+  // few properities so that content nested within behave properly.
+  > .container,
+  > .container-fluid {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    justify-content: space-between;
+
+    @include media-breakpoint-down(nth(map-keys($grid-breakpoints), 1)) {
+      width: 100%; // prevent flex parent container from collapsing
       margin-right: 0;
       margin-left: 0;
     }
@@ -36,11 +47,10 @@
 
 .navbar-brand {
   display: inline-block;
-  align-self: flex-start;
-  padding-top: .25rem;
-  padding-bottom: .25rem;
+  padding-top: $navbar-brand-padding-y;
+  padding-bottom: $navbar-brand-padding-y;
   margin-right: $navbar-padding-x;
-  font-size: $font-size-lg;
+  font-size: $navbar-brand-font-size;
   line-height: inherit;
   white-space: nowrap;
 
@@ -74,8 +84,8 @@
 
 .navbar-text {
   display: inline-block;
-  padding-top:    .425rem;
-  padding-bottom: .425rem;
+  padding-top: $nav-link-padding-y;
+  padding-bottom: $nav-link-padding-y;
 }
 
 
@@ -84,9 +94,15 @@
 // Custom styles for responsive collapsing and toggling of navbar contents.
 // Powered by the collapse Bootstrap JavaScript plugin.
 
+// When collapsed, prevent the toggleable navbar contents from appearing in
+// the default flexbox row orienation. Requires the use of `flex-wrap: wrap`
+// on the `.navbar` parent.
+.navbar-collapse {
+  flex-basis: 100%;
+}
+
 // Button for toggling the navbar when in its collapsed state
 .navbar-toggler {
-  align-self: flex-start; // Prevent toggler from growing to full width when it's the only visible navbar child
   padding: $navbar-toggler-padding-y $navbar-toggler-padding-x;
   font-size: $navbar-toggler-font-size;
   line-height: 1;
@@ -111,23 +127,12 @@
   background-size: 100% 100%;
 }
 
-// Use `position` on the toggler to prevent it from being auto placed as a flex
-// item and allow easy placement.
-.navbar-toggler-left {
-  position: absolute;
-  left: $navbar-padding-x;
-}
-.navbar-toggler-right {
-  position: absolute;
-  right: $navbar-padding-x;
-}
-
-// Generate series of `.navbar-toggleable-*` responsive classes for configuring
+// Generate series of `.navbar-expand-*` responsive classes for configuring
 // where your navbar collapses.
-.navbar-toggleable {
+.navbar-expand {
   @each $breakpoint in map-keys($grid-breakpoints) {
     $next: breakpoint-next($breakpoint, $grid-breakpoints);
-    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
+    $infix: breakpoint-infix($next, $grid-breakpoints);
 
     &#{$infix} {
       @include media-breakpoint-down($breakpoint) {
@@ -138,7 +143,8 @@
           }
         }
 
-        > .container {
+        > .container,
+        > .container-fluid {
           padding-right: 0;
           padding-left: 0;
         }
@@ -147,11 +153,15 @@
       @include media-breakpoint-up($next) {
         flex-direction: row;
         flex-wrap: nowrap;
-        align-items: center;
+        justify-content: flex-start;
 
         .navbar-nav {
           flex-direction: row;
 
+          .dropdown-menu {
+            position: absolute;
+          }
+
           .nav-link {
             padding-right: .5rem;
             padding-left: .5rem;
@@ -159,16 +169,14 @@
         }
 
         // For nesting containers, have to redeclare for alignment purposes
-        > .container {
-          display: flex;
+        > .container,
+        > .container-fluid {
           flex-wrap: nowrap;
-          align-items: center;
         }
 
         // scss-lint:disable ImportantRule
         .navbar-collapse {
           display: flex !important;
-          width: 100%;
         }
         // scss-lint:enable ImportantRule
 
@@ -187,8 +195,7 @@
 
 // Dark links against a light background
 .navbar-light {
-  .navbar-brand,
-  .navbar-toggler {
+  .navbar-brand {
     color: $navbar-light-active-color;
 
     @include hover-focus {
@@ -218,6 +225,7 @@
   }
 
   .navbar-toggler {
+    color: $navbar-light-color;
     border-color: $navbar-light-toggler-border;
   }
 
@@ -232,8 +240,7 @@
 
 // White links against a dark background
 .navbar-inverse {
-  .navbar-brand,
-  .navbar-toggler {
+  .navbar-brand {
     color: $navbar-inverse-active-color;
 
     @include hover-focus {
@@ -263,6 +270,7 @@
   }
 
   .navbar-toggler {
+    color: $navbar-inverse-color;
     border-color: $navbar-inverse-toggler-border;
   }
 
diff --git a/scss/_popover.scss b/scss/_popover.scss
index 1b6363405..82a335fa1 100644
--- a/scss/_popover.scss
+++ b/scss/_popover.scss
@@ -132,6 +132,7 @@
   padding: $popover-title-padding-y $popover-title-padding-x;
   margin-bottom: 0; // Reset the default from Reboot
   font-size: $font-size-base;
+  color: $popover-title-color;
   background-color: $popover-title-bg;
   border-bottom: $popover-border-width solid darken($popover-title-bg, 5%);
   $offset-border-width: calc(#{$border-radius-lg} - #{$popover-border-width});
@@ -144,6 +145,7 @@
 
 .popover-content {
   padding: $popover-content-padding-y $popover-content-padding-x;
+  color: $popover-content-color;
 }
 
 
diff --git a/scss/_progress.scss b/scss/_progress.scss
index ccca51e8d..66571843c 100644
--- a/scss/_progress.scss
+++ b/scss/_progress.scss
@@ -18,6 +18,7 @@
   line-height: $progress-height;
   color: $progress-bar-color;
   background-color: $progress-bar-bg;
+  @include transition($progress-bar-transition);
 }
 
 .progress-bar-striped {
diff --git a/scss/_reboot.scss b/scss/_reboot.scss
index 78753af00..c52e6f887 100644
--- a/scss/_reboot.scss
+++ b/scss/_reboot.scss
@@ -22,8 +22,8 @@ html {
   box-sizing: border-box; // 1
   font-family: sans-serif; // 2
   line-height: 1.15; // 3
-  -ms-text-size-adjust: 100%; // 4
   -webkit-text-size-adjust: 100%; // 4
+  -ms-text-size-adjust: 100%; // 4
   -ms-overflow-style: scrollbar; // 5
   -webkit-tap-highlight-color: rgba(0,0,0,0); // 6
 }
diff --git a/scss/_tables.scss b/scss/_tables.scss
index 47c3ac297..f041f6094 100644
--- a/scss/_tables.scss
+++ b/scss/_tables.scss
@@ -125,14 +125,27 @@
   th,
   td,
   thead th {
-    border-color: $body-bg;
+    border-color: $table-inverse-border;
   }
 
   &.table-bordered {
     border: 0;
   }
-}
 
+  &.table-striped {
+    tbody tr:nth-of-type(odd) {
+      background-color: $table-inverse-bg-accent;
+    }
+  }
+
+  &.table-hover {
+    tbody tr {
+      @include hover {
+        background-color: $table-inverse-bg-hover;
+      }
+    }
+  }
+}
 
 
 // Responsive tables
@@ -142,13 +155,15 @@
 // will display normally.
 
 .table-responsive {
-  display: block;
-  width: 100%;
-  overflow-x: auto;
-  -ms-overflow-style: -ms-autohiding-scrollbar; // See https://github.com/twbs/bootstrap/pull/10057
-
-  // Prevent double border on horizontal scroll due to use of `display: block;`
-  &.table-bordered {
-    border: 0;
+  @include media-breakpoint-down(md) {
+    display: block;
+    width: 100%;
+    overflow-x: auto;
+    -ms-overflow-style: -ms-autohiding-scrollbar; // See https://github.com/twbs/bootstrap/pull/10057
+
+    // Prevent double border on horizontal scroll due to use of `display: block;`
+    &.table-bordered {
+      border: 0;
+    }
   }
 }
diff --git a/scss/_type.scss b/scss/_type.scss
index 13a64b06f..fc9c791c4 100644
--- a/scss/_type.scss
+++ b/scss/_type.scss
@@ -51,8 +51,8 @@ h6, .h6 { font-size: $font-size-h6; }
 //
 
 hr {
-  margin-top: $spacer-y;
-  margin-bottom: $spacer-y;
+  margin-top: 1rem;
+  margin-bottom: 1rem;
   border: 0;
   border-top: $hr-border-width solid $hr-border-color;
 }
diff --git a/scss/_variables.scss b/scss/_variables.scss
index 09ac11a9d..f517797fa 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -21,8 +21,8 @@
 // Forms
 // Dropdowns
 // Z-index master list
-// Navbar
 // Navs
+// Navbar
 // Pagination
 // Jumbotron
 // Form states and alerts
@@ -138,36 +138,15 @@ $enable-print-styles:       true !default;
 // variables. Mostly focused on spacing.
 // You can add more entries to the $spacers map, should you need more variation.
 
-$spacer:   1rem !default;
-$spacer-x: $spacer !default;
-$spacer-y: $spacer !default;
+$spacer: 1rem !default;
 $spacers: (
-  0: (
-    x: 0,
-    y: 0
-  ),
-  1: (
-    x: ($spacer-x * .25),
-    y: ($spacer-y * .25)
-  ),
-  2: (
-    x: ($spacer-x * .5),
-    y: ($spacer-y * .5)
-  ),
-  3: (
-    x: $spacer-x,
-    y: $spacer-y
-  ),
-  4: (
-    x: ($spacer-x * 1.5),
-    y: ($spacer-y * 1.5)
-  ),
-  5: (
-    x: ($spacer-x * 3),
-    y: ($spacer-y * 3)
-  )
+  0: 0,
+  1: ($spacer * .25),
+  2: ($spacer * .5),
+  3: $spacer,
+  4: ($spacer * 1.5),
+  5: ($spacer * 3)
 ) !default;
-$border-width: 1px !default;
 
 // This variable affects the `.h-*` and `.w-*` classes.
 $sizes: (
@@ -237,11 +216,35 @@ $grid-gutter-widths: (
   xl: $grid-gutter-width-base
 ) !default;
 
+
+// Components
+//
+// Define common padding and border radius sizes and more.
+
+$line-height-lg:         1.5 !default;
+$line-height-sm:         1.5 !default;
+
+$border-width: 1px !default;
+
+$border-radius:          .25rem !default;
+$border-radius-lg:       .3rem !default;
+$border-radius-sm:       .2rem !default;
+
+$component-active-color: $white !default;
+$component-active-bg:    $brand-primary !default;
+
+$caret-width:            .3em !default;
+
+$transition-base:        all .2s ease-in-out !default;
+$transition-fade:        opacity .15s linear !default;
+$transition-collapse:    height .35s ease !default;
+
+
 // Fonts
 //
 // Font, line-height, and color for body text, headings, and more.
 
-$font-family-sans-serif: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif !default;
+$font-family-sans-serif: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif !default;
 $font-family-monospace:  Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
 $font-family-base:       $font-family-sans-serif !default;
 
@@ -305,27 +308,6 @@ $nested-kbd-font-weight: $font-weight-bold !default;
 $list-inline-padding: 5px !default;
 
 
-// Components
-//
-// Define common padding and border radius sizes and more.
-
-$line-height-lg:         (4 / 3) !default;
-$line-height-sm:         1.5 !default;
-
-$border-radius:          .25rem !default;
-$border-radius-lg:       .3rem !default;
-$border-radius-sm:       .2rem !default;
-
-$component-active-color: $white !default;
-$component-active-bg:    $brand-primary !default;
-
-$caret-width:            .3em !default;
-
-$transition-base:        all .2s ease-in-out !default;
-$transition-fade:        opacity .15s linear !default;
-$transition-collapse:    height .35s ease !default;
-
-
 // Tables
 //
 // Customizes the `.table` component with basic values, each used across all table variations.
@@ -334,28 +316,40 @@ $table-cell-padding:            .75rem !default;
 $table-sm-cell-padding:         .3rem !default;
 
 $table-bg:                      transparent !default;
-
-$table-inverse-bg:              $gray-dark !default;
-$table-inverse-color:           $body-bg !default;
-
 $table-bg-accent:               rgba($black,.05) !default;
 $table-bg-hover:                rgba($black,.075) !default;
 $table-bg-active:               $table-bg-hover !default;
 
+$table-border-width:            $border-width !default;
+$table-border-color:            $gray-lighter !default;
+
 $table-head-bg:                 $gray-lighter !default;
 $table-head-color:              $gray !default;
 
-$table-border-width:            $border-width !default;
-$table-border-color:            $gray-lighter !default;
+$table-inverse-bg:              $gray-dark !default;
+$table-inverse-bg-accent:       rgba($white, .05) !default;
+$table-inverse-bg-hover:        rgba($white, .075) !default;
+$table-inverse-bg-active:       $table-inverse-bg-hover !default;
+$table-inverse-border:          lighten($gray-dark, 7.5%) !default;
+$table-inverse-color:           $body-bg !default;
 
 
 // Buttons
 //
 // For each of Bootstrap's buttons, define text, background and border color.
 
-$btn-padding-x:                  1rem !default;
-$btn-padding-y:                  .5rem !default;
-$btn-line-height:                1.25 !default;
+$input-btn-padding-y:       .5rem !default;
+$input-btn-padding-x:       1rem !default;
+$input-btn-line-height:     1.25 !default;
+
+$input-btn-padding-y-sm:    .25rem !default;
+$input-btn-padding-x-sm:    .5rem !default;
+$input-btn-line-height-sm:  1.5 !default;
+
+$input-btn-padding-y-lg:    .5rem !default;
+$input-btn-padding-x-lg:    1rem !default;
+$input-btn-line-height-lg:  1.5 !default;
+
 $btn-font-weight:                $font-weight-normal !default;
 $btn-box-shadow:                 inset 0 1px 0 rgba($white,.15), 0 1px 1px rgba($black,.075) !default;
 $btn-focus-box-shadow:           0 0 0 2px rgba($brand-primary, .25) !default;
@@ -387,12 +381,6 @@ $btn-danger-border:              $btn-danger-bg !default;
 
 $btn-link-disabled-color:        $gray-light !default;
 
-$btn-padding-x-sm:               .5rem !default;
-$btn-padding-y-sm:               .25rem !default;
-
-$btn-padding-x-lg:               1.5rem !default;
-$btn-padding-y-lg:               .75rem !default;
-
 $btn-block-spacing-y:            .5rem !default;
 
 // Allows for customizing button radius independently from global border radius
@@ -405,10 +393,6 @@ $btn-transition:                 all .2s ease-in-out !default;
 
 // Forms
 
-$input-padding-x:                .75rem !default;
-$input-padding-y:                .5rem !default;
-$input-line-height:              1.25 !default;
-
 $input-bg:                       $white !default;
 $input-bg-disabled:              $gray-lighter !default;
 
@@ -428,15 +412,9 @@ $input-color-focus:              $input-color !default;
 
 $input-color-placeholder:        $gray-light !default;
 
-$input-padding-x-sm:             .5rem !default;
-$input-padding-y-sm:             .25rem !default;
-
-$input-padding-x-lg:             1.5rem !default;
-$input-padding-y-lg:             .75rem !default;
-
-$input-height:                   (($font-size-base * $input-line-height) + ($input-padding-y * 2)) !default;
-$input-height-lg:                (($font-size-lg * $line-height-lg) + ($input-padding-y-lg * 2)) !default;
-$input-height-sm:                (($font-size-sm * $line-height-sm) + ($input-padding-y-sm * 2)) !default;
+$input-height:                   (($font-size-base * $input-btn-line-height) + ($input-btn-padding-y * 2)) !default;
+$input-height-lg:                (($font-size-lg * $input-btn-line-height-lg) + ($input-btn-padding-y-lg * 2)) !default;
+$input-height-sm:                (($font-size-sm * $input-btn-line-height-sm) + ($input-btn-padding-y-sm * 2)) !default;
 
 $input-transition:               border-color ease-in-out .15s, box-shadow ease-in-out .15s !default;
 
@@ -450,7 +428,7 @@ $form-check-input-margin-x: .25rem !default;
 
 $form-check-inline-margin-x: .75rem !default;
 
-$form-group-margin-bottom:       $spacer-y !default;
+$form-group-margin-bottom:       1rem !default;
 
 $input-group-addon-bg:           $gray-lighter !default;
 $input-group-addon-border-color: $input-border-color !default;
@@ -458,8 +436,8 @@ $input-group-addon-border-color: $input-border-color !default;
 $cursor-disabled:                not-allowed !default;
 
 $custom-control-gutter:   1.5rem !default;
-$custom-control-spacer-x: 1rem !default;
 $custom-control-spacer-y: .25rem !default;
+$custom-control-spacer-x: 1rem !default;
 
 $custom-control-indicator-size:       1rem !default;
 $custom-control-indicator-bg:         #ddd !default;
@@ -491,10 +469,10 @@ $custom-checkbox-indeterminate-box-shadow: none !default;
 $custom-radio-radius: 50% !default;
 $custom-radio-checked-icon: str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3E%3Ccircle r='3' fill='#{$custom-control-checked-indicator-color}'/%3E%3C/svg%3E"), "#", "%23") !default;
 
-$custom-select-padding-x:          .75rem  !default;
 $custom-select-padding-y:          .375rem !default;
+$custom-select-padding-x:          .75rem  !default;
 $custom-select-indicator-padding:   1rem !default; // Extra padding to account for the presence of the background-image based indicator
-$custom-select-line-height:         $input-line-height !default;
+$custom-select-line-height:         $input-btn-line-height !default;
 $custom-select-color:               $input-color !default;
 $custom-select-disabled-color:      $gray-light !default;
 $custom-select-bg:            $white !default;
@@ -515,8 +493,8 @@ $custom-file-height:           2.5rem !default;
 $custom-file-width:            14rem !default;
 $custom-file-focus-box-shadow: 0 0 0 .075rem $white, 0 0 0 .2rem $brand-primary !default;
 
-$custom-file-padding-x:     .5rem !default;
 $custom-file-padding-y:     1rem !default;
+$custom-file-padding-x:     .5rem !default;
 $custom-file-line-height:   1.5 !default;
 $custom-file-color:         $gray !default;
 $custom-file-bg:            $white !default;
@@ -569,6 +547,7 @@ $dropdown-link-active-bg:        $component-active-bg !default;
 
 $dropdown-link-disabled-color:   $gray-light !default;
 
+$dropdown-item-padding-y:        .25rem !default;
 $dropdown-item-padding-x:        1.5rem !default;
 
 $dropdown-header-color:          $gray-light !default;
@@ -588,13 +567,42 @@ $zindex-modal:              1050 !default;
 $zindex-popover:            1060 !default;
 $zindex-tooltip:            1070 !default;
 
+// Navs
+
+$nav-item-margin:               .2rem !default;
+$nav-item-inline-spacer:        1rem !default;
+$nav-link-padding-y:            .5rem !default;
+$nav-link-padding-x:            1rem !default;
+$nav-link-hover-bg:             $gray-lighter !default;
+$nav-disabled-link-color:       $gray-light !default;
+
+$nav-tabs-border-color:                       #ddd !default;
+$nav-tabs-border-width:                       $border-width !default;
+$nav-tabs-border-radius:                      $border-radius !default;
+$nav-tabs-link-hover-border-color:            $gray-lighter !default;
+$nav-tabs-active-link-color:                  $gray !default;
+$nav-tabs-active-link-bg:                     $body-bg !default;
+$nav-tabs-active-link-border-color:           #ddd !default;
+$nav-tabs-justified-link-border-color:        #ddd !default;
+$nav-tabs-justified-active-link-border-color: $body-bg !default;
+
+$nav-pills-border-radius:     $border-radius !default;
+$nav-pills-active-link-color: $component-active-color !default;
+$nav-pills-active-link-bg:    $component-active-bg !default;
+
 // Navbar
 
-$navbar-padding-x:                  $spacer !default;
 $navbar-padding-y:                  ($spacer / 2) !default;
+$navbar-padding-x:                  $spacer !default;
+
+$navbar-brand-font-size:            $font-size-lg !default;
+// Compute the navbar-brand padding-y so the navbar-brand will have the same height as navbar-text and nav-link
+$nav-link-height:                   $navbar-brand-font-size * $line-height-base !default;
+$navbar-brand-height:               ($font-size-base * $line-height-base + $nav-link-padding-y * 2) !default;
+$navbar-brand-padding-y:            ($navbar-brand-height - $nav-link-height) / 2 !default;
 
-$navbar-toggler-padding-x:           .75rem !default;
 $navbar-toggler-padding-y:           .25rem !default;
+$navbar-toggler-padding-x:           .75rem !default;
 $navbar-toggler-font-size:           $font-size-lg !default;
 $navbar-toggler-border-radius:       $btn-border-radius !default;
 
@@ -612,32 +620,14 @@ $navbar-light-disabled-color:       rgba($black,.3) !default;
 $navbar-light-toggler-bg: str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath stroke='#{$navbar-light-color}' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E"), "#", "%23") !default;
 $navbar-light-toggler-border:       rgba($black,.1) !default;
 
-// Navs
-
-$nav-link-padding:              .5em 1em !default;
-$nav-disabled-link-color:       $gray-light !default;
-
-$nav-tabs-border-color:                       #ddd !default;
-$nav-tabs-border-width:                       $border-width !default;
-$nav-tabs-border-radius:                      $border-radius !default;
-$nav-tabs-link-hover-border-color:            $gray-lighter !default;
-$nav-tabs-active-link-color:                  $gray !default;
-$nav-tabs-active-link-bg:                     $body-bg !default;
-$nav-tabs-active-link-border-color:           #ddd !default;
-
-$nav-pills-border-radius:     $border-radius !default;
-$nav-pills-active-link-color: $component-active-color !default;
-$nav-pills-active-link-bg:    $component-active-bg !default;
-
-
 // Pagination
 
-$pagination-padding-x:                .75rem !default;
 $pagination-padding-y:                .5rem !default;
-$pagination-padding-x-sm:             .5rem !default;
+$pagination-padding-x:                .75rem !default;
 $pagination-padding-y-sm:             .25rem !default;
-$pagination-padding-x-lg:             1.5rem !default;
+$pagination-padding-x-sm:             .5rem !default;
 $pagination-padding-y-lg:             .75rem !default;
+$pagination-padding-x-lg:             1.5rem !default;
 $pagination-line-height:              1.25 !default;
 
 $pagination-color:                     $link-color !default;
@@ -688,8 +678,8 @@ $state-danger-border:            darken($state-danger-bg, 5%) !default;
 
 // Cards
 
-$card-spacer-x:            1.25rem !default;
 $card-spacer-y:            .75rem !default;
+$card-spacer-x:            1.25rem !default;
 $card-border-width:        1px !default;
 $card-border-radius:       $border-radius !default;
 $card-border-color:        rgba($black,.125) !default;
@@ -732,11 +722,13 @@ $popover-border-color:                rgba($black,.2) !default;
 $popover-box-shadow:                  0 5px 10px rgba($black,.2) !default;
 
 $popover-title-bg:                    darken($popover-bg, 3%) !default;
-$popover-title-padding-x:             14px !default;
+$popover-title-color:                 $headings-color !default;
 $popover-title-padding-y:             8px !default;
+$popover-title-padding-x:             14px !default;
 
-$popover-content-padding-x:           14px !default;
+$popover-content-color:               $body-color !default;
 $popover-content-padding-y:           9px !default;
+$popover-content-padding-x:           14px !default;
 
 $popover-arrow-width:                 10px !default;
 $popover-arrow-color:                 $popover-bg !default;
@@ -758,8 +750,8 @@ $badge-color:                 $white !default;
 $badge-link-hover-color:      $white !default;
 $badge-font-size:             75% !default;
 $badge-font-weight:           $font-weight-bold !default;
-$badge-padding-x:             .4em !default;
 $badge-padding-y:             .25em !default;
+$badge-padding-x:             .4em !default;
 
 $badge-pill-padding-x:        .6em !default;
 // Use a higher than normal value to ensure completely rounded edges when
@@ -802,9 +794,9 @@ $modal-transition:            transform .3s ease-out !default;
 //
 // Define alert colors, border radius, and padding.
 
-$alert-padding-x:             1.25rem !default;
 $alert-padding-y:             .75rem !default;
-$alert-margin-bottom:         $spacer-y !default;
+$alert-padding-x:             1.25rem !default;
+$alert-margin-bottom:         1rem !default;
 $alert-border-radius:         $border-radius !default;
 $alert-link-font-weight:      $font-weight-bold !default;
 $alert-border-width:          $border-width !default;
@@ -836,6 +828,7 @@ $progress-box-shadow:           inset 0 .1rem .1rem rgba($black,.1) !default;
 $progress-bar-color:            $white !default;
 $progress-bar-bg:               $brand-primary !default;
 $progress-bar-animation-timing: 1s linear infinite !default;
+$progress-bar-transition:       width .6s ease !default;
 
 // List group
 
@@ -845,8 +838,8 @@ $list-group-border-color:        rgba($black,.125) !default;
 $list-group-border-width:        $border-width !default;
 $list-group-border-radius:       $border-radius !default;
 
-$list-group-item-padding-x:      1.25rem !default;
 $list-group-item-padding-y:      .75rem !default;
+$list-group-item-padding-x:      1.25rem !default;
 
 $list-group-hover-bg:            $gray-lightest !default;
 $list-group-active-color:        $component-active-color !default;
@@ -924,8 +917,8 @@ $close-text-shadow:           0 1px 0 $white !default;
 // Code
 
 $code-font-size:              90% !default;
-$code-padding-x:              .4rem !default;
 $code-padding-y:              .2rem !default;
+$code-padding-x:              .4rem !default;
 $code-color:                  #bd4147 !default;
 $code-bg:                     $gray-lightest !default;
 
diff --git a/scss/mixins/_alert.scss b/scss/mixins/_alert.scss
index 6ed3a81ab..1e9307ebb 100644
--- a/scss/mixins/_alert.scss
+++ b/scss/mixins/_alert.scss
@@ -1,9 +1,9 @@
 // Alerts
 
 @mixin alert-variant($background, $border, $body-color) {
+  color: $body-color;
   background-color: $background;
   border-color: $border;
-  color: $body-color;
 
   hr {
     border-top-color: darken($border, 5%);
diff --git a/scss/mixins/_border-radius.scss b/scss/mixins/_border-radius.scss
index 54f29f41d..2024febcf 100644
--- a/scss/mixins/_border-radius.scss
+++ b/scss/mixins/_border-radius.scss
@@ -8,15 +8,15 @@
 
 @mixin border-top-radius($radius) {
   @if $enable-rounded {
-    border-top-right-radius: $radius;
     border-top-left-radius: $radius;
+    border-top-right-radius: $radius;
   }
 }
 
 @mixin border-right-radius($radius) {
   @if $enable-rounded {
-    border-bottom-right-radius: $radius;
     border-top-right-radius: $radius;
+    border-bottom-right-radius: $radius;
   }
 }
 
@@ -29,7 +29,7 @@
 
 @mixin border-left-radius($radius) {
   @if $enable-rounded {
-    border-bottom-left-radius: $radius;
     border-top-left-radius: $radius;
+    border-bottom-left-radius: $radius;
   }
 }
diff --git a/scss/mixins/_box-shadow.scss b/scss/mixins/_box-shadow.scss
new file mode 100644
index 000000000..b2410e53a
--- /dev/null
+++ b/scss/mixins/_box-shadow.scss
@@ -0,0 +1,5 @@
+@mixin box-shadow($shadow...) {
+  @if $enable-shadows {
+    box-shadow: $shadow;
+  }
+}
diff --git a/scss/mixins/_breakpoints.scss b/scss/mixins/_breakpoints.scss
index 904b60f7a..be1d034d8 100644
--- a/scss/mixins/_breakpoints.scss
+++ b/scss/mixins/_breakpoints.scss
@@ -78,10 +78,11 @@
 // Media that spans multiple breakpoint widths.
 // Makes the @content apply between the min and max breakpoints
 @mixin media-breakpoint-between($lower, $upper, $breakpoints: $grid-breakpoints) {
-  @include media-breakpoint-up($lower, $breakpoints) {
-    @include media-breakpoint-down($upper, $breakpoints) {
-      @content;
-    }
+  $min: breakpoint-max($lower, $breakpoints);
+  $max: breakpoint-max($upper, $breakpoints);
+
+  @media (min-width: $min) and (max-width: $max) {
+    @content;
   }
 }
 
@@ -89,7 +90,10 @@
 // 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: $grid-breakpoints) {
-  @include media-breakpoint-between($name, $name, $breakpoints) {
+  $min: breakpoint-min($name, $breakpoints);
+  $max: breakpoint-max($name, $breakpoints);
+
+  @media (min-width: $min) and (max-width: $max) {
     @content;
   }
 }
diff --git a/scss/mixins/_buttons.scss b/scss/mixins/_buttons.scss
index f9981e326..47f2834ff 100644
--- a/scss/mixins/_buttons.scss
+++ b/scss/mixins/_buttons.scss
@@ -48,8 +48,8 @@
 
 @mixin button-outline-variant($color, $color-hover: #fff) {
   color: $color;
-  background-image: none;
   background-color: transparent;
+  background-image: none;
   border-color: $color;
 
   @include hover {
@@ -79,8 +79,9 @@
 }
 
 // Button sizes
-@mixin button-size($padding-y, $padding-x, $font-size, $border-radius) {
+@mixin button-size($padding-y, $padding-x, $font-size, $line-height, $border-radius) {
   padding: $padding-y $padding-x;
   font-size: $font-size;
+  line-height: $line-height;
   @include border-radius($border-radius);
 }
diff --git a/scss/mixins/_clearfix.scss b/scss/mixins/_clearfix.scss
index b72cf2712..11a977b73 100644
--- a/scss/mixins/_clearfix.scss
+++ b/scss/mixins/_clearfix.scss
@@ -1,7 +1,7 @@
 @mixin clearfix() {
   &::after {
     display: block;
-    content: "";
     clear: both;
+    content: "";
   }
 }
diff --git a/scss/mixins/_forms.scss b/scss/mixins/_forms.scss
index 9fde3a8a6..33b186a8d 100644
--- a/scss/mixins/_forms.scss
+++ b/scss/mixins/_forms.scss
@@ -27,8 +27,8 @@
   // Set validation states also for addons
   .input-group-addon {
     color: $color;
-    border-color: $color;
     background-color: lighten($color, 40%);
+    border-color: $color;
   }
 }
 
diff --git a/scss/mixins/_gradients.scss b/scss/mixins/_gradients.scss
index 8bfd97c4d..bad79f961 100644
--- a/scss/mixins/_gradients.scss
+++ b/scss/mixins/_gradients.scss
@@ -17,8 +17,8 @@
 }
 
 @mixin gradient-directional($start-color: #555, $end-color: #333, $deg: 45deg) {
-  background-repeat: repeat-x;
   background-image: linear-gradient($deg, $start-color, $end-color);
+  background-repeat: repeat-x;
 }
 @mixin gradient-x-three-colors($start-color: #00b3ee, $mid-color: #7a43b6, $color-stop: 50%, $end-color: #c3325f) {
   background-image: linear-gradient(to right, $start-color, $mid-color $color-stop, $end-color);
diff --git a/scss/mixins/_grid-framework.scss b/scss/mixins/_grid-framework.scss
index 0aa814ab2..5459a86f4 100644
--- a/scss/mixins/_grid-framework.scss
+++ b/scss/mixins/_grid-framework.scss
@@ -22,7 +22,8 @@
         @extend %grid-column;
       }
     }
-    .col#{$infix} {
+    .col#{$infix},
+    .col#{$infix}-auto {
       @extend %grid-column;
     }
 
diff --git a/scss/mixins/_grid.scss b/scss/mixins/_grid.scss
index 9cd8c7bbb..87920e284 100644
--- a/scss/mixins/_grid.scss
+++ b/scss/mixins/_grid.scss
@@ -3,9 +3,8 @@
 // Generate semantic grid columns with these mixins.
 
 @mixin make-container($gutters: $grid-gutter-widths) {
-  position: relative;
-  margin-left: auto;
   margin-right: auto;
+  margin-left: auto;
 
   @each $breakpoint in map-keys($gutters) {
     @include media-breakpoint-up($breakpoint) {
@@ -68,12 +67,7 @@
 }
 
 @mixin make-col($size, $columns: $grid-columns) {
-  flex: 0 0 percentage($size / $columns);
-  // width: percentage($size / $columns);
-  // Add a `max-width` to ensure content within each column does not blow out
-  // the width of the column. Applies to IE10+ and Firefox. Chrome and Safari
-  // do not appear to require this.
-  max-width: percentage($size / $columns);
+  width: percentage($size / $columns);
 }
 
 @mixin make-col-offset($size, $columns: $grid-columns) {
diff --git a/scss/mixins/_hover.scss b/scss/mixins/_hover.scss
index 6dd55e705..4aa4b1d5d 100644
--- a/scss/mixins/_hover.scss
+++ b/scss/mixins/_hover.scss
@@ -8,16 +8,18 @@
 //    }
 //  }
 //  @else {
+// scss-lint:disable Indentation
     &:hover { @content }
+// scss-lint:enable Indentation
 //  }
 }
 
+
 @mixin hover-focus {
   @if $enable-hover-media-query {
     &:focus { @content }
     @include hover { @content }
-  }
-  @else {
+  } @else {
     &:focus,
     &:hover {
       @content
@@ -32,8 +34,7 @@
       @content
     }
     @include hover { @content }
-  }
-  @else {
+  } @else {
     &,
     &:focus,
     &:hover {
@@ -49,8 +50,7 @@
       @content
     }
     @include hover { @content }
-  }
-  @else {
+  } @else {
     &:focus,
     &:active,
     &:hover {
diff --git a/scss/mixins/_list-group.scss b/scss/mixins/_list-group.scss
index 278787bbe..ba27b5041 100644
--- a/scss/mixins/_list-group.scss
+++ b/scss/mixins/_list-group.scss
@@ -6,6 +6,7 @@
     background-color: $background;
   }
 
+  //scss-lint:disable QualifyingElement
   a.list-group-item-#{$state},
   button.list-group-item-#{$state} {
     color: $color;
@@ -21,4 +22,5 @@
       border-color: $color;
     }
   }
+  // scss-lint:enable QualifyingElement
 }
diff --git a/scss/mixins/_nav-divider.scss b/scss/mixins/_nav-divider.scss
index fb3d12e9f..493de03a3 100644
--- a/scss/mixins/_nav-divider.scss
+++ b/scss/mixins/_nav-divider.scss
@@ -3,8 +3,8 @@
 // Dividers (basically an hr) within dropdowns and nav lists
 
 @mixin nav-divider($color: #e5e5e5) {
-  height: 1px;
-  margin: ($spacer-y / 2) 0;
+  height: 0;
+  margin: ($spacer / 2) 0;
   overflow: hidden;
-  background-color: $color;
+  border-top: 1px solid $color;
 }
diff --git a/scss/mixins/_reset-text.scss b/scss/mixins/_reset-text.scss
index b95273097..4cf9e79c7 100644
--- a/scss/mixins/_reset-text.scss
+++ b/scss/mixins/_reset-text.scss
@@ -1,17 +1,18 @@
+// scss-lint:disable DuplicateProperty
 @mixin reset-text {
   font-family: $font-family-base;
   // We deliberately do NOT reset font-size or word-wrap.
   font-style: normal;
   font-weight: $font-weight-normal;
-  letter-spacing: normal;
-  line-break: auto;
   line-height: $line-height-base;
   text-align: left; // Fallback for where `start` is not supported
   text-align: start;
   text-decoration: none;
   text-shadow: none;
   text-transform: none;
-  white-space: normal;
+  letter-spacing: normal;
   word-break: normal;
   word-spacing: normal;
+  white-space: normal;
+  line-break: auto;
 }
diff --git a/scss/mixins/_resize.scss b/scss/mixins/_resize.scss
index 83fa63791..66f233a63 100644
--- a/scss/mixins/_resize.scss
+++ b/scss/mixins/_resize.scss
@@ -1,6 +1,6 @@
 // Resize anything
 
 @mixin resizable($direction) {
-  resize: $direction; // Options: horizontal, vertical, both
   overflow: auto; // Per CSS3 UI, `resize` only applies when `overflow` isn't `visible`
+  resize: $direction; // Options: horizontal, vertical, both
 }
diff --git a/scss/mixins/_screen-reader.scss b/scss/mixins/_screen-reader.scss
index c20858324..a5fa51c5c 100644
--- a/scss/mixins/_screen-reader.scss
+++ b/scss/mixins/_screen-reader.scss
@@ -1,15 +1,17 @@
 // Only display content to screen readers
 //
 // See: http://a11yproject.com/posts/how-to-hide-content
+// See: http://hugogiraudel.com/2016/10/13/css-hide-and-seek/
 
 @mixin sr-only {
   position: absolute;
   width: 1px;
   height: 1px;
   padding: 0;
-  margin: -1px;
   overflow: hidden;
   clip: rect(0,0,0,0);
+  white-space: nowrap;
+  clip-path: inset(50%);
   border: 0;
 }
 
@@ -25,8 +27,9 @@
     position: static;
     width: auto;
     height: auto;
-    margin: 0;
     overflow: visible;
     clip: auto;
+    white-space: normal;
+    clip-path: none;
   }
 }
diff --git a/scss/mixins/_text-truncate.scss b/scss/mixins/_text-truncate.scss
index 5a40bf533..3504bb1aa 100644
--- a/scss/mixins/_text-truncate.scss
+++ b/scss/mixins/_text-truncate.scss
@@ -5,4 +5,4 @@
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
-}
\ No newline at end of file
+}
diff --git a/scss/mixins/_transition.scss b/scss/mixins/_transition.scss
new file mode 100644
index 000000000..7e33dee31
--- /dev/null
+++ b/scss/mixins/_transition.scss
@@ -0,0 +1,9 @@
+@mixin transition($transition...) {
+  @if $enable-transitions {
+    @if length($transition) == 0 {
+      transition: $transition-base;
+    } @else {
+      transition: $transition;
+    }
+  }
+}
diff --git a/scss/mixins/_visibility.scss b/scss/mixins/_visibility.scss
index 88c50b05d..f67fc1c52 100644
--- a/scss/mixins/_visibility.scss
+++ b/scss/mixins/_visibility.scss
@@ -1,5 +1,5 @@
 // Visibility
 
-@mixin invisible {
-  visibility: hidden !important;
+@mixin invisible($visibility) {
+  visibility: $visibility !important;
 }
diff --git a/scss/utilities/_display.scss b/scss/utilities/_display.scss
index ae942a6fb..45353620a 100644
--- a/scss/utilities/_display.scss
+++ b/scss/utilities/_display.scss
@@ -1,5 +1,5 @@
 //
-// Display utilities
+// Utilities for common `display` values
 //
 
 @each $breakpoint in map-keys($grid-breakpoints) {
@@ -16,3 +16,38 @@
     .d#{$infix}-inline-flex  { display: inline-flex !important; }
   }
 }
+
+
+//
+// Utilities for toggling `display` in print
+//
+
+.d-print-block {
+  display: none !important;
+
+  @media print {
+    display: block !important;
+  }
+}
+
+.d-print-inline {
+  display: none !important;
+
+  @media print {
+    display: inline !important;
+  }
+}
+
+.d-print-inline-block {
+  display: none !important;
+
+  @media print {
+    display: inline-block !important;
+  }
+}
+
+.d-print-none {
+  @media print {
+    display: none !important;
+  }
+}
diff --git a/scss/utilities/_spacing.scss b/scss/utilities/_spacing.scss
index 6056e2b7e..c89816b5e 100644
--- a/scss/utilities/_spacing.scss
+++ b/scss/utilities/_spacing.scss
@@ -5,22 +5,20 @@
     $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
 
     @each $prop, $abbrev in (margin: m, padding: p) {
-      @each $size, $lengths in $spacers {
-        $length-x: map-get($lengths, x);
-        $length-y: map-get($lengths, y);
+      @each $size, $length in $spacers {
 
-        .#{$abbrev}#{$infix}-#{$size}  { #{$prop}:        $length-y $length-x !important; }
-        .#{$abbrev}t#{$infix}-#{$size} { #{$prop}-top:    $length-y !important; }
-        .#{$abbrev}r#{$infix}-#{$size} { #{$prop}-right:  $length-x !important; }
-        .#{$abbrev}b#{$infix}-#{$size} { #{$prop}-bottom: $length-y !important; }
-        .#{$abbrev}l#{$infix}-#{$size} { #{$prop}-left:   $length-x !important; }
+        .#{$abbrev}#{$infix}-#{$size}  { #{$prop}:        $length !important; }
+        .#{$abbrev}t#{$infix}-#{$size} { #{$prop}-top:    $length !important; }
+        .#{$abbrev}r#{$infix}-#{$size} { #{$prop}-right:  $length !important; }
+        .#{$abbrev}b#{$infix}-#{$size} { #{$prop}-bottom: $length !important; }
+        .#{$abbrev}l#{$infix}-#{$size} { #{$prop}-left:   $length !important; }
         .#{$abbrev}x#{$infix}-#{$size} {
-          #{$prop}-right: $length-x !important;
-          #{$prop}-left:  $length-x !important;
+          #{$prop}-right: $length !important;
+          #{$prop}-left:  $length !important;
         }
         .#{$abbrev}y#{$infix}-#{$size} {
-          #{$prop}-top:    $length-y !important;
-          #{$prop}-bottom: $length-y !important;
+          #{$prop}-top:    $length !important;
+          #{$prop}-bottom: $length !important;
         }
       }
     }
diff --git a/scss/utilities/_visibility.scss b/scss/utilities/_visibility.scss
index fcedc9cb9..823406dc3 100644
--- a/scss/utilities/_visibility.scss
+++ b/scss/utilities/_visibility.scss
@@ -2,54 +2,10 @@
 // Visibility utilities
 //
 
-.invisible {
-  @include invisible();
-}
-
-// Responsive visibility utilities
-
-@each $bp in map-keys($grid-breakpoints) {
-  .hidden-#{$bp}-up {
-    @include media-breakpoint-up($bp) {
-      display: none !important;
-    }
-  }
-  .hidden-#{$bp}-down {
-    @include media-breakpoint-down($bp) {
-      display: none !important;
-    }
-  }
+.visible {
+  @include invisible(visible);
 }
 
-
-// Print utilities
-//
-// Media queries are placed on the inside to be mixin-friendly.
-
-.visible-print-block {
-  display: none !important;
-
-  @media print {
-    display: block !important;
-  }
-}
-.visible-print-inline {
-  display: none !important;
-
-  @media print {
-    display: inline !important;
-  }
-}
-.visible-print-inline-block {
-  display: none !important;
-
-  @media print {
-    display: inline-block !important;
-  }
-}
-
-.hidden-print {
-  @media print {
-    display: none !important;
-  }
+.invisible {
+  @include invisible(hidden);
 }