rake update[v4-dev]

25 files changed, 254 insertions, 214 deletions

diff --git a/assets/stylesheets/bootstrap/_badge.scss b/assets/stylesheets/bootstrap/_badge.scss
index 8a76263..fea10eb 100644
--- a/assets/stylesheets/bootstrap/_badge.scss
+++ b/assets/stylesheets/bootstrap/_badge.scss
@@ -9,7 +9,6 @@
   font-size: $badge-font-size;
   font-weight: $badge-font-weight;
   line-height: 1;
-  color: $badge-color;
   text-align: center;
   white-space: nowrap;
   vertical-align: baseline;
diff --git a/assets/stylesheets/bootstrap/_breadcrumb.scss b/assets/stylesheets/bootstrap/_breadcrumb.scss
index 2bc0e20..52fadec 100644
--- a/assets/stylesheets/bootstrap/_breadcrumb.scss
+++ b/assets/stylesheets/bootstrap/_breadcrumb.scss
@@ -1,6 +1,6 @@
 .breadcrumb {
   padding: $breadcrumb-padding-y $breadcrumb-padding-x;
-  margin-bottom: 1rem;
+  margin-bottom: $breadcrumb-margin-bottom;
   list-style: none;
   background-color: $breadcrumb-bg;
   @include border-radius($border-radius);
diff --git a/assets/stylesheets/bootstrap/_button-group.scss b/assets/stylesheets/bootstrap/_button-group.scss
index 30a14d8..4063506 100644
--- a/assets/stylesheets/bootstrap/_button-group.scss
+++ b/assets/stylesheets/bootstrap/_button-group.scss
@@ -10,7 +10,6 @@
   > .btn {
     position: relative;
     flex: 0 1 auto;
-    margin-bottom: 0;
 
     // Bring the hover, focused, and "active" buttons to the front to overlay
     // the borders properly
@@ -66,15 +65,18 @@
 .btn-group > .btn-group {
   float: left;
 }
+
 .btn-group > .btn-group:not(:first-child):not(:last-child) > .btn {
   border-radius: 0;
 }
+
 .btn-group > .btn-group:first-child:not(:last-child) {
   > .btn:last-child,
   > .dropdown-toggle {
     @include border-right-radius(0);
   }
 }
+
 .btn-group > .btn-group:last-child:not(:first-child) > .btn:first-child {
   @include border-left-radius(0);
 }
@@ -129,7 +131,6 @@
 //
 
 .btn-group-vertical {
-  display: inline-flex;
   flex-direction: column;
   align-items: flex-start;
   justify-content: center;
@@ -146,30 +147,35 @@
     margin-top: -$input-btn-border-width;
     margin-left: 0;
   }
-}
 
-.btn-group-vertical > .btn {
-  &:not(:first-child):not(:last-child) {
-    border-radius: 0;
+  > .btn {
+    &:not(:first-child):not(:last-child) {
+      border-radius: 0;
+    }
   }
+
   &:first-child:not(:last-child) {
     @include border-bottom-radius(0);
   }
+
   &:last-child:not(:first-child) {
     @include border-top-radius(0);
   }
-}
-.btn-group-vertical > .btn-group:not(:first-child):not(:last-child) > .btn {
-  border-radius: 0;
-}
-.btn-group-vertical > .btn-group:first-child:not(:last-child) {
-  > .btn:last-child,
-  > .dropdown-toggle {
-    @include border-bottom-radius(0);
+
+  > .btn-group:not(:first-child):not(:last-child) > .btn {
+    border-radius: 0;
+  }
+
+  > .btn-group:first-child:not(:last-child) {
+    > .btn:last-child,
+    > .dropdown-toggle {
+      @include border-bottom-radius(0);
+    }
+  }
+
+  > .btn-group:last-child:not(:first-child) > .btn:first-child {
+    @include border-top-radius(0);
   }
-}
-.btn-group-vertical > .btn-group:last-child:not(:first-child) > .btn:first-child {
-  @include border-top-radius(0);
 }
 
 
diff --git a/assets/stylesheets/bootstrap/_buttons.scss b/assets/stylesheets/bootstrap/_buttons.scss
index 607f24a..c6dbb5d 100644
--- a/assets/stylesheets/bootstrap/_buttons.scss
+++ b/assets/stylesheets/bootstrap/_buttons.scss
@@ -58,7 +58,11 @@ fieldset[disabled] a.btn {
 
 @each $color, $value in $theme-colors {
   .btn-outline-#{$color} {
-    @include button-outline-variant($value, #fff);
+    @if $color == "light" {
+      @include button-outline-variant($value, $gray-900);
+    } @else {
+      @include button-outline-variant($value, $white);
+    }
   }
 }
 
@@ -71,36 +75,28 @@ fieldset[disabled] a.btn {
 .btn-link {
   font-weight: $font-weight-normal;
   color: $link-color;
+  background-color: transparent;
   border-radius: 0;
 
-  &,
-  &:active,
-  &.active,
-  &:disabled {
+  @include hover {
+    color: $link-hover-color;
+    text-decoration: $link-hover-decoration;
     background-color: transparent;
-    @include box-shadow(none);
+    border-color: transparent;
   }
-  &,
+
   &:focus,
-  &:active {
+  &.focus {
     border-color: transparent;
     box-shadow: none;
   }
-  @include hover {
-    border-color: transparent;
-  }
-  @include hover-focus {
-    color: $link-hover-color;
-    text-decoration: $link-hover-decoration;
-    background-color: transparent;
-  }
-  &:disabled {
-    color: $btn-link-disabled-color;
 
-    @include hover-focus {
-      text-decoration: none;
-    }
+  &:disabled,
+  &.disabled {
+    color: $btn-link-disabled-color;
   }
+
+  // No need for an active state here
 }
 
 
@@ -109,11 +105,11 @@ fieldset[disabled] a.btn {
 //
 
 .btn-lg {
-  @include button-size($input-btn-padding-y-lg, $input-btn-padding-x-lg, $font-size-lg, $line-height-lg, $btn-border-radius-lg);
+  @include button-size($input-btn-padding-y-lg, $input-btn-padding-x-lg, $font-size-lg, $input-btn-line-height-lg, $btn-border-radius-lg);
 }
 
 .btn-sm {
-  @include button-size($input-btn-padding-y-sm, $input-btn-padding-x-sm, $font-size-sm, $line-height-sm, $btn-border-radius-sm);
+  @include button-size($input-btn-padding-y-sm, $input-btn-padding-x-sm, $font-size-sm, $input-btn-line-height-sm, $btn-border-radius-sm);
 }
 
 
diff --git a/assets/stylesheets/bootstrap/_card.scss b/assets/stylesheets/bootstrap/_card.scss
index 1ab85a4..40fa425 100644
--- a/assets/stylesheets/bootstrap/_card.scss
+++ b/assets/stylesheets/bootstrap/_card.scss
@@ -56,6 +56,10 @@
       @include border-bottom-radius($card-border-radius);
     }
   }
+
+  .card-header + .list-group > .list-group-item:first-child {
+    border-top: 0;
+  }
 }
 
 
@@ -130,9 +134,15 @@
 
 // Card deck
 
-@include media-breakpoint-up(sm) {
-  .card-deck {
-    display: flex;
+.card-deck {
+  display: flex;
+  flex-direction: column;
+
+  .card {
+    margin-bottom: $card-deck-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
     flex-flow: row wrap;
     margin-right: -$card-deck-margin;
     margin-left: -$card-deck-margin;
@@ -142,6 +152,7 @@
       flex: 1 0 0%;
       flex-direction: column;
       margin-right: $card-deck-margin;
+      margin-bottom: 0; // Override the default
       margin-left: $card-deck-margin;
     }
   }
@@ -152,13 +163,20 @@
 // Card groups
 //
 
-@include media-breakpoint-up(sm) {
-  .card-group {
-    display: flex;
+.card-group {
+  display: flex;
+  flex-direction: column;
+
+  .card {
+    margin-bottom: $card-group-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
     flex-flow: row wrap;
 
     .card {
       flex: 1 0 0%;
+      margin-bottom: 0;
 
       + .card {
         margin-left: 0;
@@ -177,6 +195,7 @@
             border-bottom-right-radius: 0;
           }
         }
+
         &:last-child {
           @include border-left-radius(0);
 
diff --git a/assets/stylesheets/bootstrap/_custom-forms.scss b/assets/stylesheets/bootstrap/_custom-forms.scss
index d1fbf95..1bf268b 100644
--- a/assets/stylesheets/bootstrap/_custom-forms.scss
+++ b/assets/stylesheets/bootstrap/_custom-forms.scss
@@ -139,6 +139,7 @@
   color: $custom-select-color;
   vertical-align: middle;
   background: $custom-select-bg $custom-select-indicator no-repeat right $custom-select-padding-x center;
+  background-clip: padding-box;
   background-size: $custom-select-bg-size;
   border: $custom-select-border-width solid $custom-select-border-color;
   @if $enable-rounded {
@@ -203,7 +204,7 @@
   opacity: 0;
 
   &:focus ~ .custom-file-control {
-    @include box-shadow($custom-file-focus-box-shadow);
+    box-shadow: $custom-file-focus-box-shadow;
   }
 }
 
@@ -214,12 +215,14 @@
   left: 0;
   z-index: 5;
   height: $custom-file-height;
-  padding: $custom-file-padding-x $custom-file-padding-y;
+  padding: $custom-file-padding-y $custom-file-padding-x;
+  overflow: hidden;
   line-height: $custom-file-line-height;
   color: $custom-file-color;
   pointer-events: none;
   user-select: none;
   background-color: $custom-file-bg;
+  background-clip: padding-box;
   border: $custom-file-border-width solid $custom-file-border-color;
   @include border-radius($custom-file-border-radius);
   @include box-shadow($custom-file-box-shadow);
@@ -232,18 +235,16 @@
 
   &::before {
     position: absolute;
-    top: -$custom-file-border-width;
-    right: -$custom-file-border-width;
-    bottom: -$custom-file-border-width;
+    top: 0;
+    right: 0;
     z-index: 6;
     display: block;
     height: $custom-file-height;
-    padding: $custom-file-padding-x $custom-file-padding-y;
+    padding: $custom-file-padding-y $custom-file-padding-x;
     line-height: $custom-file-line-height;
     color: $custom-file-button-color;
     background-color: $custom-file-button-bg;
-    border: $custom-file-border-width solid $custom-file-border-color;
-    @include border-radius(0 $custom-file-border-radius $custom-file-border-radius 0);
+    border-left: $custom-file-border-width solid $custom-file-border-color;
   }
 
   @each $lang, $text in map-get($custom-file-text, button-label) {
diff --git a/assets/stylesheets/bootstrap/_forms.scss b/assets/stylesheets/bootstrap/_forms.scss
index 519554b..33163a0 100644
--- a/assets/stylesheets/bootstrap/_forms.scss
+++ b/assets/stylesheets/bootstrap/_forms.scss
@@ -7,8 +7,6 @@
 .form-control {
   display: block;
   width: 100%;
-  // // Make inputs at least the height of their button counterpart (base line-height + padding + border)
-  // height: $input-height;
   padding: $input-btn-padding-y $input-btn-padding-x;
   font-size: $font-size-base;
   line-height: $input-btn-line-height;
@@ -236,23 +234,16 @@ select.form-control-lg {
   position: absolute;
   margin-top: $form-check-input-margin-y;
   margin-left: -$form-check-input-gutter;
-
-  &:only-child {
-    position: static;
-  }
 }
 
 // Radios and checkboxes on same line
 .form-check-inline {
   display: inline-block;
+  margin-right: $form-check-inline-margin-x;
 
   .form-check-label {
     vertical-align: middle;
   }
-
-  + .form-check-inline {
-    margin-left: $form-check-inline-margin-x;
-  }
 }
 
 
diff --git a/assets/stylesheets/bootstrap/_functions.scss b/assets/stylesheets/bootstrap/_functions.scss
index 6c0601c..a63680a 100644
--- a/assets/stylesheets/bootstrap/_functions.scss
+++ b/assets/stylesheets/bootstrap/_functions.scss
@@ -72,7 +72,7 @@
   @return map-get($theme-colors, $key);
 }
 
-@function grayscale($key: "100") {
+@function gray($key: "100") {
   @return map-get($grays, $key);
 }
 
diff --git a/assets/stylesheets/bootstrap/_grid.scss b/assets/stylesheets/bootstrap/_grid.scss
index 9ab9ae0..a227515 100644
--- a/assets/stylesheets/bootstrap/_grid.scss
+++ b/assets/stylesheets/bootstrap/_grid.scss
@@ -16,7 +16,6 @@
 
 @if $enable-grid-classes {
   .container-fluid {
-    width: 100%;
     @include make-container();
   }
 }
diff --git a/assets/stylesheets/bootstrap/_input-group.scss b/assets/stylesheets/bootstrap/_input-group.scss
index 0b668bf..95b17be 100644
--- a/assets/stylesheets/bootstrap/_input-group.scss
+++ b/assets/stylesheets/bootstrap/_input-group.scss
@@ -5,6 +5,7 @@
 .input-group {
   position: relative;
   display: flex;
+  align-items: center;
   width: 100%;
 
   .form-control {
@@ -28,10 +29,6 @@
 .input-group-addon,
 .input-group-btn,
 .input-group .form-control {
-  // Vertically centers the content of the addons within the input group
-  display: flex;
-  align-items: center;
-
   &:not(:first-child):not(:last-child) {
     @include border-radius(0);
   }
@@ -40,7 +37,6 @@
 .input-group-addon,
 .input-group-btn {
   white-space: nowrap;
-  vertical-align: middle; // Match the inputs
 }
 
 
@@ -71,9 +67,10 @@
   font-size: $font-size-base; // Match inputs
   font-weight: $font-weight-normal;
   line-height: $input-btn-line-height;
-  color: $input-color;
+  color: $input-group-addon-color;
   text-align: center;
   background-color: $input-group-addon-bg;
+  background-clip: padding-box;
   border: $input-btn-border-width solid $input-group-addon-border-color;
   @include border-radius($input-border-radius);
 
@@ -144,6 +141,8 @@
   // element above the siblings.
   > .btn {
     position: relative;
+    background-clip: padding-box;
+    border: $input-btn-border-width solid $input-group-btn-border-color;
 
     + .btn {
       margin-left: (-$input-btn-border-width);
diff --git a/assets/stylesheets/bootstrap/_modal.scss b/assets/stylesheets/bootstrap/_modal.scss
index c0c4067..a563e6f 100644
--- a/assets/stylesheets/bootstrap/_modal.scss
+++ b/assets/stylesheets/bootstrap/_modal.scss
@@ -43,6 +43,8 @@
   position: relative;
   width: auto;
   margin: $modal-dialog-margin;
+  // allow clicks to pass through for custom click handling to close modal
+  pointer-events: none;
 }
 
 // Actual modal
@@ -50,6 +52,8 @@
   position: relative;
   display: flex;
   flex-direction: column;
+  // counteract the pointer-events: none; in the .modal-dialog
+  pointer-events: auto;
   background-color: $modal-content-bg;
   background-clip: padding-box;
   border: $modal-content-border-width solid $modal-content-border-color;
@@ -82,6 +86,10 @@
   justify-content: space-between; // Put modal header elements (title and dismiss) on opposite ends
   padding: $modal-header-padding;
   border-bottom: $modal-header-border-width solid $modal-header-border-color;
+
+  .close {
+    margin-left: auto; // Force icon to the right even when there's no .modal-title
+  }
 }
 
 // Title text within header
diff --git a/assets/stylesheets/bootstrap/_pagination.scss b/assets/stylesheets/bootstrap/_pagination.scss
index a049299..4ef1442 100644
--- a/assets/stylesheets/bootstrap/_pagination.scss
+++ b/assets/stylesheets/bootstrap/_pagination.scss
@@ -38,7 +38,7 @@
   position: relative;
   display: block;
   padding: $pagination-padding-y $pagination-padding-x;
-  margin-left: -1px;
+  margin-left: -$pagination-border-width;
   line-height: $pagination-line-height;
   color: $pagination-color;
   background-color: $pagination-bg;
diff --git a/assets/stylesheets/bootstrap/_progress.scss b/assets/stylesheets/bootstrap/_progress.scss
index f7491a6..efbb440 100644
--- a/assets/stylesheets/bootstrap/_progress.scss
+++ b/assets/stylesheets/bootstrap/_progress.scss
@@ -5,21 +5,19 @@
 
 .progress {
   display: flex;
+  height: $progress-height;
   overflow: hidden; // force rounded corners by cropping it
   font-size: $progress-font-size;
-  line-height: $progress-height;
-  text-align: center;
   background-color: $progress-bg;
   @include border-radius($progress-border-radius);
-  @include box-shadow($progress-box-shadow);
 }
 
 .progress-bar {
-  height: $progress-height;
-  line-height: $progress-height;
+  display: flex;
+  align-items: center;
+  justify-content: center;
   color: $progress-bar-color;
   background-color: $progress-bar-bg;
-  @include transition($progress-bar-transition);
 }
 
 .progress-bar-striped {
diff --git a/assets/stylesheets/bootstrap/_reboot.scss b/assets/stylesheets/bootstrap/_reboot.scss
index 33fc2d6..41f084b 100644
--- a/assets/stylesheets/bootstrap/_reboot.scss
+++ b/assets/stylesheets/bootstrap/_reboot.scss
@@ -18,8 +18,13 @@
 //    we force a non-overlapping, non-auto-hiding scrollbar to counteract.
 // 6. Change the default tap highlight to be completely transparent in iOS.
 
-html {
+*,
+*::before,
+*::after {
   box-sizing: border-box; // 1
+}
+
+html {
   font-family: sans-serif; // 2
   line-height: 1.15; // 3
   -webkit-text-size-adjust: 100%; // 4
@@ -28,12 +33,6 @@ html {
   -webkit-tap-highlight-color: rgba(0,0,0,0); // 6
 }
 
-*,
-*::before,
-*::after {
-  box-sizing: inherit; // 1
-}
-
 // IE10+ doesn't honor `<meta name="viewport">` in some cases.
 @at-root {
   @-ms-viewport { width: device-width; }
@@ -48,6 +47,8 @@ article, aside, dialog, figcaption, figure, footer, header, hgroup, main, nav, s
 //
 // 1. Remove the margin in all browsers.
 // 2. As a best practice, apply a default `background-color`.
+// 3. Set an explicit initial text-align value so that we can later use the
+//    the `inherit` value on things like `<th>` elements.
 
 body {
   margin: 0; // 1
@@ -56,6 +57,7 @@ body {
   font-weight: $font-weight-base;
   line-height: $line-height-base;
   color: $body-color;
+  text-align: left; // 3
   background-color: $body-bg; // 2
 }
 
@@ -100,7 +102,7 @@ h1, h2, h3, h4, h5, h6 {
 // bottom margin to use `rem` units instead of `em`.
 p {
   margin-top: 0;
-  margin-bottom: 1rem;
+  margin-bottom: $paragraph-margin-bottom;
 }
 
 // Abbreviations
@@ -270,7 +272,7 @@ svg:not(:root) {
 // DON'T remove the click delay when `<meta name="viewport" content="width=device-width">` is present.
 // However, they DO support removing the click delay via `touch-action: manipulation`.
 // See:
-// * https://v4-alpha.getbootstrap.com/content/reboot/#click-delay-optimization-for-touch
+// * https://getbootstrap.com/docs/4.0/content/reboot/#click-delay-optimization-for-touch
 // * http://caniuse.com/#feat=css-touch-action
 // * https://patrickhlauke.github.io/touch/tests/results/#suppressing-300ms-delay
 
@@ -278,7 +280,7 @@ a,
 area,
 button,
 [role="button"],
-input,
+input:not([type=range]),
 label,
 select,
 summary,
@@ -304,8 +306,9 @@ caption {
 }
 
 th {
-  // Matches default `<td>` alignment
-  text-align: left;
+  // Matches default `<td>` alignment by inheriting from the `<body>`, or the
+  // closest parent with a set `text-align`.
+  text-align: inherit;
 }
 
 
diff --git a/assets/stylesheets/bootstrap/_tables.scss b/assets/stylesheets/bootstrap/_tables.scss
index a652d17..3238439 100644
--- a/assets/stylesheets/bootstrap/_tables.scss
+++ b/assets/stylesheets/bootstrap/_tables.scss
@@ -99,32 +99,36 @@
 @include table-row-variant(active, $table-active-bg);
 
 
-// Inverse styles
+// Dark styles
 //
 // Same table markup, but inverted color scheme: dark background and light text.
 
-.thead-inverse {
-  th {
-    color: $table-inverse-color;
-    background-color: $table-inverse-bg;
+.table {
+  .thead-dark {
+    th {
+      color: $table-dark-color;
+      background-color: $table-dark-bg;
+      border-color: $table-dark-border-color;
+    }
   }
-}
 
-.thead-default {
-  th {
-    color: $table-head-color;
-    background-color: $table-head-bg;
+  .thead-light {
+    th {
+      color: $table-head-color;
+      background-color: $table-head-bg;
+      border-color: $table-border-color;
+    }
   }
 }
 
-.table-inverse {
-  color: $table-inverse-color;
-  background-color: $table-inverse-bg;
+.table-dark {
+  color: $table-dark-color;
+  background-color: $table-dark-bg;
 
   th,
   td,
   thead th {
-    border-color: $table-inverse-border-color;
+    border-color: $table-dark-border-color;
   }
 
   &.table-bordered {
@@ -133,14 +137,14 @@
 
   &.table-striped {
     tbody tr:nth-of-type(odd) {
-      background-color: $table-inverse-accent-bg;
+      background-color: $table-dark-accent-bg;
     }
   }
 
   &.table-hover {
     tbody tr {
       @include hover {
-        background-color: $table-inverse-hover-bg;
+        background-color: $table-dark-hover-bg;
       }
     }
   }
@@ -149,20 +153,27 @@
 
 // Responsive tables
 //
-// Add `.table-responsive` to `.table`s and we'll make them mobile friendly by
-// enabling horizontal scrolling. Only applies <768px. Everything above that
-// will display normally.
+// Generate series of `.table-responsive-*` classes for configuring the screen
+// size of where your table will overflow.
 
 .table-responsive {
-  @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;
+  @each $breakpoint in map-keys($grid-breakpoints) {
+    $next: breakpoint-next($breakpoint, $grid-breakpoints);
+    $infix: breakpoint-infix($next, $grid-breakpoints);
+
+    &#{$infix} {
+      @include media-breakpoint-down($breakpoint) {
+        display: block;
+        width: 100%;
+        overflow-x: auto;
+        -webkit-overflow-scrolling: touch;
+        -ms-overflow-style: -ms-autohiding-scrollbar; // See https://github.com/twbs/bootstrap/pull/10057
+
+        // Prevent double border on horizontal scroll due to use of `display: block;`
+        &.table-bordered {
+          border: 0;
+        }
+      }
     }
   }
 }
diff --git a/assets/stylesheets/bootstrap/_variables.scss b/assets/stylesheets/bootstrap/_variables.scss
index e2bacef..c0b5494 100644
--- a/assets/stylesheets/bootstrap/_variables.scss
+++ b/assets/stylesheets/bootstrap/_variables.scss
@@ -1,48 +1,8 @@
 // Variables
 //
-// Copy settings from this file into the provided `_custom.scss` to override
-// the Bootstrap defaults without modifying key, versioned files.
-//
 // Variables should follow the `$component-state-property-size` formula for
 // consistent naming. Ex: $nav-link-disabled-color and $modal-content-box-shadow-xs.
 
-// Table of Contents
-//
-// Color system
-// Options
-// Spacing
-// Body
-// Links
-// Grid breakpoints
-// Grid containers
-// Grid columns
-// Fonts
-// Components
-// Tables
-// Buttons
-// Forms
-// Dropdowns
-// Z-index master list
-// Navs
-// Navbar
-// Pagination
-// Jumbotron
-// Form states and alerts
-// Cards
-// Tooltips
-// Popovers
-// Badges
-// Modals
-// Alerts
-// Progress bars
-// List group
-// Image thumbnails
-// Figures
-// Breadcrumbs
-// Carousel
-// Close
-// Code
-
 
 //
 // Color system
@@ -60,7 +20,8 @@ $gray-800: #343a40 !default;
 $gray-900: #212529 !default;
 $black:  #000 !default;
 
-$grays: (
+$grays: () !default;
+$grays: map-merge((
   100: $gray-100,
   200: $gray-200,
   300: $gray-300,
@@ -70,7 +31,7 @@ $grays: (
   700: $gray-700,
   800: $gray-800,
   900: $gray-900
-) !default;
+), $grays);
 
 $blue:    #007bff !default;
 $indigo:  #6610f2 !default;
@@ -83,7 +44,8 @@ $green:   #28a745 !default;
 $teal:    #20c997 !default;
 $cyan:    #17a2b8 !default;
 
-$colors: (
+$colors: () !default;
+$colors: map-merge((
   blue: $blue,
   indigo: $indigo,
   purple: $purple,
@@ -97,9 +59,10 @@ $colors: (
   white: $white,
   gray: $gray-600,
   gray-dark: $gray-800
-) !default;
+), $colors);
 
-$theme-colors: (
+$theme-colors: () !default;
+$theme-colors: map-merge((
   primary: $blue,
   secondary: $gray-600,
   success: $green,
@@ -108,7 +71,7 @@ $theme-colors: (
   danger: $red,
   light: $gray-100,
   dark: $gray-800
-) !default;
+), $theme-colors);
 
 // Set a specific jump point for requesting color jumps
 $theme-color-interval: 8% !default;
@@ -167,6 +130,12 @@ $link-decoration:       none !default;
 $link-hover-color:      darken($link-color, 15%) !default;
 $link-hover-decoration: underline !default;
 
+// Paragraphs
+//
+// Style p element.
+
+$paragraph-margin-bottom: 1rem !default;
+
 
 // Grid breakpoints
 //
@@ -212,6 +181,7 @@ $line-height-lg:         1.5 !default;
 $line-height-sm:         1.5 !default;
 
 $border-width: 1px !default;
+$border-color: $gray-200 !default;
 
 $border-radius:          .25rem !default;
 $border-radius-lg:       .3rem !default;
@@ -231,14 +201,15 @@ $transition-collapse:    height .35s ease !default;
 //
 // Font, line-height, and color for body text, headings, and more.
 
-$font-family-sans-serif: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif !default;
-$font-family-monospace:  Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
+$font-family-sans-serif: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol" !default;
+$font-family-monospace:  "SFMono-Regular", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
 $font-family-base:       $font-family-sans-serif !default;
 
 $font-size-base: 1rem !default; // Assumes the browser default, typically `16px`
 $font-size-lg:   1.25rem !default;
 $font-size-sm:   .875rem !default;
 
+$font-weight-light: 300 !default;
 $font-weight-normal: normal !default;
 $font-weight-bold: bold !default;
 
@@ -312,11 +283,11 @@ $table-border-color:            $gray-200 !default;
 $table-head-bg:                 $gray-200 !default;
 $table-head-color:              $gray-700 !default;
 
-$table-inverse-bg:              $gray-900 !default;
-$table-inverse-accent-bg:       rgba($white, .05) !default;
-$table-inverse-hover-bg:        rgba($white, .075) !default;
-$table-inverse-border-color:    lighten($gray-900, 7.5%) !default;
-$table-inverse-color:           $body-bg !default;
+$table-dark-bg:              $gray-900 !default;
+$table-dark-accent-bg:       rgba($white, .05) !default;
+$table-dark-hover-bg:        rgba($white, .075) !default;
+$table-dark-border-color:    lighten($gray-900, 7.5%) !default;
+$table-dark-color:           $body-bg !default;
 
 
 // Buttons
@@ -349,7 +320,7 @@ $btn-border-radius:              $border-radius !default;
 $btn-border-radius-lg:           $border-radius-lg !default;
 $btn-border-radius-sm:           $border-radius-sm !default;
 
-$btn-transition:                 all .15s ease-in-out !default;
+$btn-transition:                 background-color .15s ease-in-out, border-color .15s ease-in-out, box-shadow .15s ease-in-out !default;
 
 
 // Forms
@@ -381,7 +352,7 @@ $input-height:                  calc(#{$input-height-inner} + #{$input-height-bo
 $input-height-inner-sm:         ($font-size-sm * $input-btn-line-height-sm) + ($input-btn-padding-y-sm * 2) !default;
 $input-height-sm:               calc(#{$input-height-inner-sm} + #{$input-height-border}) !default;
 
-$input-height-inner-lg:         ($font-size-sm * $input-btn-line-height-lg) + ($input-btn-padding-y-lg * 2) !default;
+$input-height-inner-lg:         ($font-size-lg * $input-btn-line-height-lg) + ($input-btn-padding-y-lg * 2) !default;
 $input-height-lg:               calc(#{$input-height-inner-lg} + #{$input-height-border}) !default;
 
 $input-transition:               border-color ease-in-out .15s, box-shadow ease-in-out .15s !default;
@@ -397,8 +368,10 @@ $form-check-inline-margin-x: .75rem !default;
 
 $form-group-margin-bottom:       1rem !default;
 
+$input-group-addon-color:        $input-color !default;
 $input-group-addon-bg:           $gray-200 !default;
 $input-group-addon-border-color: $input-border-color !default;
+$input-group-btn-border-color:   $input-border-color !default;
 
 $custom-control-gutter:   1.5rem !default;
 $custom-control-spacer-y: .25rem !default;
@@ -455,21 +428,21 @@ $custom-select-focus-box-shadow:   inset 0 1px 2px rgba($black, .075), 0 0 5px r
 $custom-select-font-size-sm:  75% !default;
 $custom-select-height-sm: $input-height-sm !default;
 
-$custom-file-height:           2.5rem !default;
+$custom-file-height:           $input-height !default;
 $custom-file-width:            14rem !default;
 $custom-file-focus-box-shadow: 0 0 0 .075rem $white, 0 0 0 .2rem theme-color("primary") !default;
 
-$custom-file-padding-y:     1rem !default;
-$custom-file-padding-x:     .5rem !default;
-$custom-file-line-height:   1.5 !default;
-$custom-file-color:         $gray-700 !default;
-$custom-file-bg:            $white !default;
-$custom-file-border-width:  $border-width !default;
+$custom-file-padding-y:     $input-btn-padding-y !default;
+$custom-file-padding-x:     $input-btn-padding-x !default;
+$custom-file-line-height:   $input-btn-line-height !default;
+$custom-file-color:         $input-color !default;
+$custom-file-bg:            $input-bg !default;
+$custom-file-border-width:  $input-btn-border-width !default;
 $custom-file-border-color:  $input-border-color !default;
-$custom-file-border-radius: $border-radius !default;
-$custom-file-box-shadow:    inset 0 .2rem .4rem rgba($black,.05) !default;
+$custom-file-border-radius: $input-border-radius !default;
+$custom-file-box-shadow:    $input-box-shadow !default;
 $custom-file-button-color:  $custom-file-color !default;
-$custom-file-button-bg:     $gray-200 !default;
+$custom-file-button-bg:     $input-group-addon-bg !default;
 $custom-file-text: (
   placeholder: (
     en: "Choose file..."
@@ -612,7 +585,7 @@ $jumbotron-bg:                   $gray-200 !default;
 
 $card-spacer-y:            .75rem !default;
 $card-spacer-x:            1.25rem !default;
-$card-border-width:        1px !default;
+$card-border-width:        $border-width !default;
 $card-border-radius:       $border-radius !default;
 $card-border-color:        rgba($black,.125) !default;
 $card-inner-border-radius: calc(#{$card-border-radius} - #{$card-border-width}) !default;
@@ -621,7 +594,8 @@ $card-bg:                  $white !default;
 
 $card-img-overlay-padding: 1.25rem !default;
 
-$card-deck-margin:          ($grid-gutter-width / 2) !default;
+$card-group-margin:         ($grid-gutter-width / 2) !default;
+$card-deck-margin:          $card-group-margin !default;
 
 $card-columns-count:        3 !default;
 $card-columns-gap:          1.25rem !default;
@@ -672,7 +646,6 @@ $popover-arrow-outer-color:           fade-in($popover-border-color, .05) !defau
 
 // Badges
 
-$badge-color:                 $white !default;
 $badge-font-size:             75% !default;
 $badge-font-weight:           $font-weight-bold !default;
 $badge-padding-y:             .25em !default;
@@ -787,6 +760,8 @@ $breadcrumb-padding-y:          .75rem !default;
 $breadcrumb-padding-x:          1rem !default;
 $breadcrumb-item-padding:       .5rem !default;
 
+$breadcrumb-margin-bottom:      1rem !default;
+
 $breadcrumb-bg:                 $gray-200 !default;
 $breadcrumb-divider-color:      $gray-600 !default;
 $breadcrumb-active-color:       $gray-600 !default;
diff --git a/assets/stylesheets/bootstrap/mixins/_breakpoints.scss b/assets/stylesheets/bootstrap/mixins/_breakpoints.scss
index 8d7378d..082c5f9 100644
--- a/assets/stylesheets/bootstrap/mixins/_breakpoints.scss
+++ b/assets/stylesheets/bootstrap/mixins/_breakpoints.scss
@@ -98,8 +98,12 @@
       @content;
     }
   } @else if $max == null {
-    @include media-breakpoint-up($name)
+    @include media-breakpoint-up($name) {
+      @content;
+    }
   } @else if $min == null {
-    @include media-breakpoint-down($name)
+    @include media-breakpoint-down($name) {
+      @content;
+    }
   }
 }
diff --git a/assets/stylesheets/bootstrap/mixins/_buttons.scss b/assets/stylesheets/bootstrap/mixins/_buttons.scss
index f7ec576..312a18f 100644
--- a/assets/stylesheets/bootstrap/mixins/_buttons.scss
+++ b/assets/stylesheets/bootstrap/mixins/_buttons.scss
@@ -9,7 +9,7 @@
   border-color: $border;
   @include box-shadow($btn-box-shadow);
 
-  &:hover {
+  @include hover {
     @include color-yiq($background);
     background-color: $active-background;
     border-color: $active-border;
diff --git a/assets/stylesheets/bootstrap/mixins/_forms.scss b/assets/stylesheets/bootstrap/mixins/_forms.scss
index 4a1e0bc..67e198c 100644
--- a/assets/stylesheets/bootstrap/mixins/_forms.scss
+++ b/assets/stylesheets/bootstrap/mixins/_forms.scss
@@ -33,8 +33,8 @@
         box-shadow: 0 0 0 .2rem rgba($color,.25);
       }
 
-      ~ .invalid-feedback,
-      ~ .invalid-tooltip {
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
         display: block;
       }
     }
diff --git a/assets/stylesheets/bootstrap/mixins/_grid-framework.scss b/assets/stylesheets/bootstrap/mixins/_grid-framework.scss
index d8195dd..a9e7c75 100644
--- a/assets/stylesheets/bootstrap/mixins/_grid-framework.scss
+++ b/assets/stylesheets/bootstrap/mixins/_grid-framework.scss
@@ -51,6 +51,15 @@
           order: $i;
         }
       }
+
+      // `$columns - 1` because offsetting by the width of an entire row isn't possible
+      @for $i from 0 through ($columns - 1) {
+        @if not ($infix == "" and $i == 0) { // Avoid emitting useless .offset-0
+          .offset#{$infix}-#{$i} {
+            @include make-col-offset($i, $columns)
+          }
+        }
+      }
     }
   }
 }
diff --git a/assets/stylesheets/bootstrap/mixins/_grid.scss b/assets/stylesheets/bootstrap/mixins/_grid.scss
index 67dbcd3..584c78b 100644
--- a/assets/stylesheets/bootstrap/mixins/_grid.scss
+++ b/assets/stylesheets/bootstrap/mixins/_grid.scss
@@ -3,11 +3,11 @@
 // Generate semantic grid columns with these mixins.
 
 @mixin make-container() {
+  width: 100%;
   margin-right: auto;
   margin-left: auto;
   padding-right: ($grid-gutter-width / 2);
   padding-left:  ($grid-gutter-width / 2);
-  width: 100%;
 }
 
 
@@ -45,3 +45,7 @@
   // do not appear to require this.
   max-width: percentage($size / $columns);
 }
+
+@mixin make-col-offset($size, $columns: $grid-columns) {
+  margin-left: percentage($size / $columns);
+}
diff --git a/assets/stylesheets/bootstrap/utilities/_borders.scss b/assets/stylesheets/bootstrap/utilities/_borders.scss
index 82e177c..b7e91c2 100644
--- a/assets/stylesheets/bootstrap/utilities/_borders.scss
+++ b/assets/stylesheets/bootstrap/utilities/_borders.scss
@@ -2,7 +2,7 @@
 // Border
 //
 
-.border          { border: 1px solid $gray-200 !important; }
+.border          { border: $border-width solid $border-color !important; }
 .border-0        { border: 0 !important; }
 .border-top-0    { border-top: 0 !important; }
 .border-right-0  { border-right: 0 !important; }
diff --git a/assets/stylesheets/bootstrap/utilities/_position.scss b/assets/stylesheets/bootstrap/utilities/_position.scss
index 74b8d39..bddae21 100644
--- a/assets/stylesheets/bootstrap/utilities/_position.scss
+++ b/assets/stylesheets/bootstrap/utilities/_position.scss
@@ -1,4 +1,13 @@
-// Positioning
+// Common values
+
+// Sass list not in variables since it's not intended for customization.
+$positions: static, relative, absolute, fixed, sticky;
+
+@each $position in $positions {
+  .position-#{$position} { position: $position !important; }
+}
+
+// Shorthand
 
 .fixed-top {
   position: fixed;
diff --git a/assets/stylesheets/bootstrap/utilities/_spacing.scss b/assets/stylesheets/bootstrap/utilities/_spacing.scss
index c89816b..150d316 100644
--- a/assets/stylesheets/bootstrap/utilities/_spacing.scss
+++ b/assets/stylesheets/bootstrap/utilities/_spacing.scss
@@ -7,35 +7,43 @@
     @each $prop, $abbrev in (margin: m, padding: p) {
       @each $size, $length in $spacers {
 
-        .#{$abbrev}#{$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}#{$infix}-#{$size} { #{$prop}: $length !important; }
+        .#{$abbrev}t#{$infix}-#{$size},
+        .#{$abbrev}y#{$infix}-#{$size} {
+          #{$prop}-top: $length !important;
+        }
+        .#{$abbrev}r#{$infix}-#{$size},
         .#{$abbrev}x#{$infix}-#{$size} {
           #{$prop}-right: $length !important;
-          #{$prop}-left:  $length !important;
         }
+        .#{$abbrev}b#{$infix}-#{$size},
         .#{$abbrev}y#{$infix}-#{$size} {
-          #{$prop}-top:    $length !important;
           #{$prop}-bottom: $length !important;
         }
+        .#{$abbrev}l#{$infix}-#{$size},
+        .#{$abbrev}x#{$infix}-#{$size} {
+          #{$prop}-left: $length !important;
+        }
       }
     }
 
     // Some special margin utils
-    .m#{$infix}-auto  { margin:        auto !important; }
-    .mt#{$infix}-auto { margin-top:    auto !important; }
-    .mr#{$infix}-auto { margin-right:  auto !important; }
-    .mb#{$infix}-auto { margin-bottom: auto !important; }
-    .ml#{$infix}-auto { margin-left:   auto !important; }
+    .m#{$infix}-auto { margin: auto !important; }
+    .mt#{$infix}-auto,
+    .my#{$infix}-auto {
+      margin-top: auto !important;
+    }
+    .mr#{$infix}-auto,
     .mx#{$infix}-auto {
       margin-right: auto !important;
-      margin-left:  auto !important;
     }
+    .mb#{$infix}-auto,
     .my#{$infix}-auto {
-      margin-top:    auto !important;
       margin-bottom: auto !important;
     }
+    .ml#{$infix}-auto,
+    .mx#{$infix}-auto {
+      margin-left: auto !important;
+    }
   }
 }
diff --git a/assets/stylesheets/bootstrap/utilities/_text.scss b/assets/stylesheets/bootstrap/utilities/_text.scss
index d337e0d..7573f29 100644
--- a/assets/stylesheets/bootstrap/utilities/_text.scss
+++ b/assets/stylesheets/bootstrap/utilities/_text.scss
@@ -28,9 +28,10 @@
 
 // Weight and italics
 
-.font-weight-normal { font-weight: $font-weight-normal; }
-.font-weight-bold   { font-weight: $font-weight-bold; }
-.font-italic        { font-style: italic; }
+.font-weight-light  { font-weight: $font-weight-light !important; }
+.font-weight-normal { font-weight: $font-weight-normal !important; }
+.font-weight-bold   { font-weight: $font-weight-bold !important; }
+.font-italic        { font-style: italic !important; }
 
 // Contextual colors