From 2bb5568533f77bfbeb6ca50ec3a464a69a238bde Mon Sep 17 00:00:00 2001
From: Gleb Mazovetskiy <glex.spb@gmail.com>
Date: Fri, 29 Dec 2017 03:59:01 +0200
Subject: rake update[v4-dev]

---
 assets/stylesheets/_bootstrap-grid.scss            |   2 +-
 assets/stylesheets/_bootstrap-reboot.scss          |   2 +-
 assets/stylesheets/_bootstrap.scss                 |   4 +-
 assets/stylesheets/bootstrap/_alert.scss           |   2 +-
 assets/stylesheets/bootstrap/_button-group.scss    |  90 ++------
 assets/stylesheets/bootstrap/_buttons.scss         |  25 ++-
 assets/stylesheets/bootstrap/_card.scss            |   9 +-
 assets/stylesheets/bootstrap/_close.scss           |   7 +-
 assets/stylesheets/bootstrap/_code.scss            |  14 +-
 assets/stylesheets/bootstrap/_custom-forms.scss    | 195 +++++++++--------
 assets/stylesheets/bootstrap/_dropdown.scss        |  30 ++-
 assets/stylesheets/bootstrap/_forms.scss           | 113 ++++------
 assets/stylesheets/bootstrap/_functions.scss       |   4 +-
 assets/stylesheets/bootstrap/_input-group.scss     | 239 ++++++++-------------
 assets/stylesheets/bootstrap/_list-group.scss      |   3 +-
 assets/stylesheets/bootstrap/_modal.scss           |  12 ++
 assets/stylesheets/bootstrap/_nav.scss             |   4 +-
 assets/stylesheets/bootstrap/_navbar.scss          |   7 +-
 assets/stylesheets/bootstrap/_pagination.scss      |   8 +
 assets/stylesheets/bootstrap/_popover.scss         | 223 +++++++++----------
 assets/stylesheets/bootstrap/_progress.scss        |   5 +-
 assets/stylesheets/bootstrap/_reboot.scss          |   3 +-
 assets/stylesheets/bootstrap/_tables.scss          |   2 +-
 assets/stylesheets/bootstrap/_tooltip.scss         | 122 ++++++-----
 assets/stylesheets/bootstrap/_type.scss            |   4 +-
 assets/stylesheets/bootstrap/_variables.scss       | 182 ++++++++++------
 .../bootstrap/mixins/_background-variant.scss      |   3 +-
 .../stylesheets/bootstrap/mixins/_breakpoints.scss |   6 +-
 assets/stylesheets/bootstrap/mixins/_buttons.scss  |  43 ++--
 assets/stylesheets/bootstrap/mixins/_caret.scss    |  30 +++
 assets/stylesheets/bootstrap/mixins/_forms.scss    |  56 +++--
 .../stylesheets/bootstrap/mixins/_text-hide.scss   |   1 +
 .../stylesheets/bootstrap/utilities/_borders.scss  |   7 +-
 33 files changed, 769 insertions(+), 688 deletions(-)

(limited to 'assets/stylesheets')

diff --git a/assets/stylesheets/_bootstrap-grid.scss b/assets/stylesheets/_bootstrap-grid.scss
index 34b4fd9..94d40a4 100644
--- a/assets/stylesheets/_bootstrap-grid.scss
+++ b/assets/stylesheets/_bootstrap-grid.scss
@@ -1,5 +1,5 @@
 /*!
- * Bootstrap Grid v4.0.0-beta.2 (https://getbootstrap.com)
+ * Bootstrap Grid v4.0.0-beta.3 (https://getbootstrap.com)
  * Copyright 2011-2017 The Bootstrap Authors
  * Copyright 2011-2017 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
diff --git a/assets/stylesheets/_bootstrap-reboot.scss b/assets/stylesheets/_bootstrap-reboot.scss
index 976e7e7..b285bc7 100644
--- a/assets/stylesheets/_bootstrap-reboot.scss
+++ b/assets/stylesheets/_bootstrap-reboot.scss
@@ -1,5 +1,5 @@
 /*!
- * Bootstrap Reboot v4.0.0-beta.2 (https://getbootstrap.com)
+ * Bootstrap Reboot v4.0.0-beta.3 (https://getbootstrap.com)
  * Copyright 2011-2017 The Bootstrap Authors
  * Copyright 2011-2017 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
diff --git a/assets/stylesheets/_bootstrap.scss b/assets/stylesheets/_bootstrap.scss
index ccc5186..966cb67 100644
--- a/assets/stylesheets/_bootstrap.scss
+++ b/assets/stylesheets/_bootstrap.scss
@@ -1,5 +1,5 @@
 /*!
- * Bootstrap v4.0.0-beta.2 (https://getbootstrap.com)
+ * Bootstrap v4.0.0-beta.3 (https://getbootstrap.com)
  * Copyright 2011-2017 The Bootstrap Authors
  * Copyright 2011-2017 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
@@ -9,7 +9,6 @@
 @import "bootstrap/variables";
 @import "bootstrap/mixins";
 @import "bootstrap/root";
-@import "bootstrap/print";
 @import "bootstrap/reboot";
 @import "bootstrap/type";
 @import "bootstrap/images";
@@ -40,3 +39,4 @@
 @import "bootstrap/popover";
 @import "bootstrap/carousel";
 @import "bootstrap/utilities";
+@import "bootstrap/print";
diff --git a/assets/stylesheets/bootstrap/_alert.scss b/assets/stylesheets/bootstrap/_alert.scss
index c2d5c81..dd43e23 100644
--- a/assets/stylesheets/bootstrap/_alert.scss
+++ b/assets/stylesheets/bootstrap/_alert.scss
@@ -46,6 +46,6 @@
 
 @each $color, $value in $theme-colors {
   .alert-#{$color} {
-    @include alert-variant(theme-color-level($color, -10), theme-color-level($color, -9), theme-color-level($color, 6));
+    @include alert-variant(theme-color-level($color, $alert-bg-level), theme-color-level($color, $alert-border-level), theme-color-level($color, $alert-color-level));
   }
 }
diff --git a/assets/stylesheets/bootstrap/_button-group.scss b/assets/stylesheets/bootstrap/_button-group.scss
index 12d4982..c1b8265 100644
--- a/assets/stylesheets/bootstrap/_button-group.scss
+++ b/assets/stylesheets/bootstrap/_button-group.scss
@@ -28,7 +28,7 @@
   .btn + .btn-group,
   .btn-group + .btn,
   .btn-group + .btn-group {
-    margin-left: -$input-btn-border-width;
+    margin-left: -$btn-border-width;
   }
 }
 
@@ -44,46 +44,18 @@
 }
 
 .btn-group {
-  > .btn:not(:first-child):not(:last-child):not(.dropdown-toggle) {
-    border-radius: 0;
-  }
-
-  // Set corners individual because sometimes a single button can be in a .btn-group
-  // and we need :first-child and :last-child to both match
   > .btn:first-child {
     margin-left: 0;
-
-    &:not(:last-child):not(.dropdown-toggle) {
-      @include border-right-radius(0);
-    }
-  }
-
-
-  // Need .dropdown-toggle since :last-child doesn't apply given a .dropdown-menu
-  // immediately after it
-  > .btn:last-child:not(:first-child),
-  > .dropdown-toggle:not(:first-child) {
-    @include border-left-radius(0);
-  }
-
-  // Custom edits for including btn-groups within btn-groups (useful for including
-  // dropdown buttons within a btn-group)
-  > .btn-group {
-    float: left;
-  }
-
-  > .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-right-radius(0);
-    }
+  // Reset rounded corners
+  > .btn:not(:last-child):not(.dropdown-toggle),
+  > .btn-group:not(:last-child) > .btn {
+    @include border-right-radius(0);
   }
 
-  > .btn-group:last-child:not(:first-child) > .btn:first-child {
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) > .btn {
     @include border-left-radius(0);
   }
 }
@@ -100,9 +72,9 @@
 // Split button dropdowns
 //
 
-.btn + .dropdown-toggle-split {
-  padding-right: $input-btn-padding-x * .75;
-  padding-left: $input-btn-padding-x * .75;
+.dropdown-toggle-split {
+  padding-right: $btn-padding-x * .75;
+  padding-left: $btn-padding-x * .75;
 
   &::after {
     margin-left: 0;
@@ -110,13 +82,13 @@
 }
 
 .btn-sm + .dropdown-toggle-split {
-  padding-right: $input-btn-padding-x-sm * .75;
-  padding-left: $input-btn-padding-x-sm * .75;
+  padding-right: $btn-padding-x-sm * .75;
+  padding-left: $btn-padding-x-sm * .75;
 }
 
 .btn-lg + .dropdown-toggle-split {
-  padding-right: $input-btn-padding-x-lg * .75;
-  padding-left: $input-btn-padding-x-lg * .75;
+  padding-right: $btn-padding-x-lg * .75;
+  padding-left: $btn-padding-x-lg * .75;
 }
 
 
@@ -150,36 +122,18 @@
   > .btn + .btn-group,
   > .btn-group + .btn,
   > .btn-group + .btn-group {
-    margin-top: -$input-btn-border-width;
+    margin-top: -$btn-border-width;
     margin-left: 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: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);
-    }
+  // Reset rounded corners
+  > .btn:not(:last-child):not(.dropdown-toggle),
+  > .btn-group:not(:last-child) > .btn {
+    @include border-bottom-radius(0);
   }
 
-  > .btn-group:last-child:not(:first-child) > .btn:first-child {
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) > .btn {
     @include border-top-radius(0);
   }
 }
@@ -197,7 +151,7 @@
 // See https://github.com/twbs/bootstrap/pull/12794 and
 // https://github.com/twbs/bootstrap/pull/14559 for more information.
 
-[data-toggle="buttons"] {
+.btn-group-toggle {
   > .btn,
   > .btn-group > .btn {
     margin-bottom: 0; // Override default `<label>` value
diff --git a/assets/stylesheets/bootstrap/_buttons.scss b/assets/stylesheets/bootstrap/_buttons.scss
index 16a478e..3a5f5ee 100644
--- a/assets/stylesheets/bootstrap/_buttons.scss
+++ b/assets/stylesheets/bootstrap/_buttons.scss
@@ -11,31 +11,41 @@
   white-space: nowrap;
   vertical-align: middle;
   user-select: none;
-  border: $input-btn-border-width solid transparent;
-  @include button-size($input-btn-padding-y, $input-btn-padding-x, $font-size-base, $input-btn-line-height, $btn-border-radius);
+  border: $btn-border-width solid transparent;
+  @include button-size($btn-padding-y, $btn-padding-x, $font-size-base, $btn-line-height, $btn-border-radius);
   @include transition($btn-transition);
 
   // Share hover and focus styles
   @include hover-focus {
     text-decoration: none;
   }
+
   &:focus,
   &.focus {
     outline: 0;
-    box-shadow: $input-btn-focus-box-shadow;
+    box-shadow: $btn-focus-box-shadow;
   }
 
   // Disabled comes first so active can properly restyle
   &.disabled,
   &:disabled {
-    opacity: .65;
+    opacity: $btn-disabled-opacity;
     @include box-shadow(none);
   }
 
+  // Opinionated: add "hand" cursor to non-disabled .btn elements
+  &:not([disabled]):not(.disabled) {
+    cursor: pointer;
+  }
+
   &:not([disabled]):not(.disabled):active,
   &:not([disabled]):not(.disabled).active {
     background-image: none;
-    @include box-shadow($input-btn-focus-box-shadow, $btn-active-box-shadow);
+    @include box-shadow($btn-active-box-shadow);
+
+    &:focus {
+      @include box-shadow($btn-focus-box-shadow, $btn-active-box-shadow);
+    }
   }
 }
 
@@ -86,6 +96,7 @@ fieldset[disabled] a.btn {
 
   &:focus,
   &.focus {
+    text-decoration: $link-hover-decoration;
     border-color: transparent;
     box-shadow: none;
   }
@@ -104,11 +115,11 @@ fieldset[disabled] a.btn {
 //
 
 .btn-lg {
-  @include button-size($input-btn-padding-y-lg, $input-btn-padding-x-lg, $font-size-lg, $input-btn-line-height-lg, $btn-border-radius-lg);
+  @include button-size($btn-padding-y-lg, $btn-padding-x-lg, $font-size-lg, $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, $input-btn-line-height-sm, $btn-border-radius-sm);
+  @include button-size($btn-padding-y-sm, $btn-padding-x-sm, $font-size-sm, $btn-line-height-sm, $btn-border-radius-sm);
 }
 
 
diff --git a/assets/stylesheets/bootstrap/_card.scss b/assets/stylesheets/bootstrap/_card.scss
index a3a435a..4c4845c 100644
--- a/assets/stylesheets/bootstrap/_card.scss
+++ b/assets/stylesheets/bootstrap/_card.scss
@@ -172,14 +172,17 @@
   display: flex;
   flex-direction: column;
 
-  .card {
+  // The child selector allows nested `.card` within `.card-group`
+  // to display properly.
+  > .card {
     margin-bottom: $card-group-margin;
   }
 
   @include media-breakpoint-up(sm) {
     flex-flow: row wrap;
-
-    .card {
+    // The child selector allows nested `.card` within `.card-group`
+    // to display properly.
+    > .card {
       // Flexbugs #4: https://github.com/philipwalton/flexbugs#4-flex-shorthand-declarations-with-unitless-flex-basis-values-are-ignored
       flex: 1 0 0%;
       margin-bottom: 0;
diff --git a/assets/stylesheets/bootstrap/_close.scss b/assets/stylesheets/bootstrap/_close.scss
index 897d486..f1763cc 100644
--- a/assets/stylesheets/bootstrap/_close.scss
+++ b/assets/stylesheets/bootstrap/_close.scss
@@ -12,6 +12,11 @@
     text-decoration: none;
     opacity: .75;
   }
+
+  // Opinionated: add "hand" cursor to non-disabled .close elements
+  &:not([disabled]):not(.disabled) {
+    cursor: pointer;
+  }
 }
 
 // Additional properties for button version
@@ -22,7 +27,7 @@
 // stylelint-disable property-no-vendor-prefix, selector-no-qualifying-type
 button.close {
   padding: 0;
-  background: transparent;
+  background-color: transparent;
   border: 0;
   -webkit-appearance: none;
 }
diff --git a/assets/stylesheets/bootstrap/_code.scss b/assets/stylesheets/bootstrap/_code.scss
index a9fe624..9de20fa 100644
--- a/assets/stylesheets/bootstrap/_code.scss
+++ b/assets/stylesheets/bootstrap/_code.scss
@@ -8,24 +8,20 @@ samp {
 
 // Inline code
 code {
-  padding: $code-padding-y $code-padding-x;
   font-size: $code-font-size;
   color: $code-color;
-  background-color: $code-bg;
-  @include border-radius($border-radius);
+  word-break: break-word;
 
   // Streamline the style when inside anchors to avoid broken underline and more
   a > & {
-    padding: 0;
     color: inherit;
-    background-color: inherit;
   }
 }
 
 // User input typically entered via keyboard
 kbd {
-  padding: $code-padding-y $code-padding-x;
-  font-size: $code-font-size;
+  padding: $kbd-padding-y $kbd-padding-x;
+  font-size: $kbd-font-size;
   color: $kbd-color;
   background-color: $kbd-bg;
   @include border-radius($border-radius-sm);
@@ -47,11 +43,9 @@ pre {
 
   // Account for some code outputs that place code tags in pre tags
   code {
-    padding: 0;
     font-size: inherit;
     color: inherit;
-    background-color: transparent;
-    @include border-radius(0);
+    word-break: normal;
   }
 }
 
diff --git a/assets/stylesheets/bootstrap/_custom-forms.scss b/assets/stylesheets/bootstrap/_custom-forms.scss
index a521dbd..d99a86d 100644
--- a/assets/stylesheets/bootstrap/_custom-forms.scss
+++ b/assets/stylesheets/bootstrap/_custom-forms.scss
@@ -9,9 +9,13 @@
 
 .custom-control {
   position: relative;
-  display: inline-flex;
+  display: block;
   min-height: (1rem * $line-height-base);
   padding-left: $custom-control-gutter;
+}
+
+.custom-control-inline {
+  display: inline-flex;
   margin-right: $custom-control-spacer-x;
 }
 
@@ -20,71 +24,98 @@
   z-index: -1; // Put the input behind the label so it doesn't overlay text
   opacity: 0;
 
-  &:checked ~ .custom-control-indicator {
+  &:checked ~ .custom-control-label::before {
     color: $custom-control-indicator-checked-color;
     @include gradient-bg($custom-control-indicator-checked-bg);
     @include box-shadow($custom-control-indicator-checked-box-shadow);
   }
 
-  &:focus ~ .custom-control-indicator {
+  &:focus ~ .custom-control-label::before {
     // the mixin is not used here to make sure there is feedback
     box-shadow: $custom-control-indicator-focus-box-shadow;
   }
 
-  &:active ~ .custom-control-indicator {
+  &:active ~ .custom-control-label::before {
     color: $custom-control-indicator-active-color;
-    @include gradient-bg($custom-control-indicator-active-bg);
+    background-color: $custom-control-indicator-active-bg;
     @include box-shadow($custom-control-indicator-active-box-shadow);
   }
 
   &:disabled {
-    ~ .custom-control-indicator {
-      background-color: $custom-control-indicator-disabled-bg;
-    }
+    ~ .custom-control-label {
+      color: $custom-control-label-disabled-color;
 
-    ~ .custom-control-description {
-      color: $custom-control-description-disabled-color;
+      &::before {
+        background-color: $custom-control-indicator-disabled-bg;
+      }
     }
   }
 }
 
-// Custom indicator
+// Custom control indicators
 //
-// Generates a shadow element to create our makeshift checkbox/radio background.
+// Build the custom controls out of psuedo-elements.
 
-.custom-control-indicator {
-  position: absolute;
-  top: (($line-height-base - $custom-control-indicator-size) / 2);
-  left: 0;
-  display: block;
-  width: $custom-control-indicator-size;
-  height: $custom-control-indicator-size;
-  pointer-events: none;
-  user-select: none;
-  background-color: $custom-control-indicator-bg;
-  background-repeat: no-repeat;
-  background-position: center center;
-  background-size: $custom-control-indicator-bg-size;
-  @include box-shadow($custom-control-indicator-box-shadow);
+.custom-control-label {
+  margin-bottom: 0;
+
+  // Background-color and (when enabled) gradient
+  &::before {
+    position: absolute;
+    top: (($line-height-base - $custom-control-indicator-size) / 2);
+    left: 0;
+    display: block;
+    width: $custom-control-indicator-size;
+    height: $custom-control-indicator-size;
+    pointer-events: none;
+    content: "";
+    user-select: none;
+    background-color: $custom-control-indicator-bg;
+    @include box-shadow($custom-control-indicator-box-shadow);
+  }
+
+  // Foreground (icon)
+  &::after {
+    position: absolute;
+    top: (($line-height-base - $custom-control-indicator-size) / 2);
+    left: 0;
+    display: block;
+    width: $custom-control-indicator-size;
+    height: $custom-control-indicator-size;
+    content: "";
+    background-repeat: no-repeat;
+    background-position: center center;
+    background-size: $custom-control-indicator-bg-size;
+  }
 }
 
+
 // Checkboxes
 //
 // Tweak just a few things for checkboxes.
 
 .custom-checkbox {
-  .custom-control-indicator {
+  .custom-control-label::before {
     @include border-radius($custom-checkbox-indicator-border-radius);
   }
 
-  .custom-control-input:checked ~ .custom-control-indicator {
-    background-image: $custom-checkbox-indicator-icon-checked;
+  .custom-control-input:checked ~ .custom-control-label {
+    &::before {
+      @include gradient-bg($custom-control-indicator-checked-bg);
+    }
+    &::after {
+      background-image: $custom-checkbox-indicator-icon-checked;
+    }
   }
 
-  .custom-control-input:indeterminate ~ .custom-control-indicator {
-    background-color: $custom-checkbox-indicator-indeterminate-bg;
-    background-image: $custom-checkbox-indicator-icon-indeterminate;
-    @include box-shadow($custom-checkbox-indicator-indeterminate-box-shadow);
+  .custom-control-input:indeterminate ~ .custom-control-label {
+    &::before {
+      @include gradient-bg($custom-checkbox-indicator-indeterminate-bg);
+      @include box-shadow($custom-checkbox-indicator-indeterminate-box-shadow);
+    }
+    &::after {
+      background-image: $custom-checkbox-indicator-icon-indeterminate;
+    }
   }
 }
 
@@ -93,30 +124,16 @@
 // Tweak just a few things for radios.
 
 .custom-radio {
-  .custom-control-indicator {
+  .custom-control-label::before {
     border-radius: $custom-radio-indicator-border-radius;
   }
 
-  .custom-control-input:checked ~ .custom-control-indicator {
-    background-image: $custom-radio-indicator-icon-checked;
-  }
-}
-
-
-// Layout options
-//
-// By default radios and checkboxes are `inline-block` with no additional spacing
-// set. Use these optional classes to tweak the layout.
-
-.custom-controls-stacked {
-  display: flex;
-  flex-direction: column;
-
-  .custom-control {
-    margin-bottom: $custom-control-spacer-y;
-
-    + .custom-control {
-      margin-left: 0;
+  .custom-control-input:checked ~ .custom-control-label {
+    &::before {
+      @include gradient-bg($custom-control-indicator-checked-bg);
+    }
+    &::after {
+      background-image: $custom-radio-indicator-icon-checked;
     }
   }
 }
@@ -130,7 +147,7 @@
 
 .custom-select {
   display: inline-block;
-  max-width: 100%;
+  width: 100%;
   height: $input-height;
   padding: $custom-select-padding-y ($custom-select-padding-x + $custom-select-indicator-padding) $custom-select-padding-y $custom-select-padding-x;
   line-height: $custom-select-line-height;
@@ -148,12 +165,12 @@
 
   &:focus {
     border-color: $custom-select-focus-border-color;
-    outline: none;
-    @include box-shadow($custom-select-focus-box-shadow);
+    outline: 0;
+    box-shadow: $custom-select-focus-box-shadow;
 
     &::-ms-value {
       // For visual consistency with other platforms/browsers,
-      // supress the default white text on blue background highlight given to
+      // suppress the default white text on blue background highlight given to
       // the selected option text when the (still closed) <select> receives focus
       // in IE and (under certain conditions) Edge.
       // See https://github.com/twbs/bootstrap/issues/19398.
@@ -162,8 +179,10 @@
     }
   }
 
-  &[multiple] {
+  &[multiple],
+  &[size]:not([size="1"]) {
     height: auto;
+    padding-right: $custom-select-padding-x;
     background-image: none;
   }
 
@@ -185,6 +204,13 @@
   font-size: $custom-select-font-size-sm;
 }
 
+.custom-select-lg {
+  height: $custom-select-height-lg;
+  padding-top: $custom-select-padding-y;
+  padding-bottom: $custom-select-padding-y;
+  font-size: $custom-select-font-size-lg;
+}
+
 
 // File
 //
@@ -193,65 +219,64 @@
 .custom-file {
   position: relative;
   display: inline-block;
-  max-width: 100%;
+  width: 100%;
   height: $custom-file-height;
   margin-bottom: 0;
 }
 
 .custom-file-input {
-  min-width: $custom-file-width;
-  max-width: 100%;
+  position: relative;
+  z-index: 2;
+  width: 100%;
   height: $custom-file-height;
   margin: 0;
   opacity: 0;
 
   &:focus ~ .custom-file-control {
+    border-color: $custom-file-focus-border-color;
     box-shadow: $custom-file-focus-box-shadow;
+
+    &::before {
+      border-color: $custom-file-focus-border-color;
+    }
+  }
+
+  @each $lang, $value in $custom-file-text {
+    &:lang(#{$lang}) ~ .custom-file-label::after {
+      content: $value;
+    }
   }
 }
 
-.custom-file-control {
+.custom-file-label {
   position: absolute;
   top: 0;
   right: 0;
   left: 0;
-  z-index: 5;
+  z-index: 1;
   height: $custom-file-height;
   padding: $custom-file-padding-y $custom-file-padding-x;
   line-height: $custom-file-line-height;
   color: $custom-file-color;
-  pointer-events: none;
-  user-select: none;
   background-color: $custom-file-bg;
   border: $custom-file-border-width solid $custom-file-border-color;
   @include border-radius($custom-file-border-radius);
   @include box-shadow($custom-file-box-shadow);
 
-  @each $lang, $text in map-get($custom-file-text, placeholder) {
-    &:lang(#{$lang}):empty::after {
-      content: $text;
-    }
-  }
-
-  &::before {
+  &::after {
     position: absolute;
-    top: -$custom-file-border-width;
-    right: -$custom-file-border-width;
-    bottom: -$custom-file-border-width;
-    z-index: 6;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    z-index: 3;
     display: block;
-    height: $custom-file-height;
+    height: calc(#{$custom-file-height} - #{$custom-file-border-width} * 2);
     padding: $custom-file-padding-y $custom-file-padding-x;
     line-height: $custom-file-line-height;
     color: $custom-file-button-color;
+    content: "Browse";
     @include gradient-bg($custom-file-button-bg);
-    border: $custom-file-border-width solid $custom-file-border-color;
+    border-left: $custom-file-border-width solid $custom-file-border-color;
     @include border-radius(0 $custom-file-border-radius $custom-file-border-radius 0);
   }
-
-  @each $lang, $text in map-get($custom-file-text, button-label) {
-    &:lang(#{$lang})::before {
-      content: $text;
-    }
-  }
 }
diff --git a/assets/stylesheets/bootstrap/_dropdown.scss b/assets/stylesheets/bootstrap/_dropdown.scss
index 2717641..a9d4cfe 100644
--- a/assets/stylesheets/bootstrap/_dropdown.scss
+++ b/assets/stylesheets/bootstrap/_dropdown.scss
@@ -44,6 +44,34 @@
   }
 }
 
+.dropright {
+  .dropdown-menu {
+    margin-top: 0;
+    margin-left: $dropdown-spacer;
+  }
+
+  .dropdown-toggle {
+    @include caret(right);
+    &::after {
+      vertical-align: 0;
+    }
+  }
+}
+
+.dropleft {
+  .dropdown-menu {
+    margin-top: 0;
+    margin-right: $dropdown-spacer;
+  }
+
+  .dropdown-toggle {
+    @include caret(left);
+    &::before {
+      vertical-align: 0;
+    }
+  }
+}
+
 // Dividers (basically an `<hr>`) within the dropdown
 .dropdown-divider {
   @include nav-divider($dropdown-divider-bg);
@@ -61,7 +89,7 @@
   color: $dropdown-link-color;
   text-align: inherit; // For `<button>`s
   white-space: nowrap; // prevent links from randomly breaking onto new lines
-  background: none; // For `<button>`s
+  background-color: transparent; // For `<button>`s
   border: 0; // For `<button>`s
 
   @include hover-focus {
diff --git a/assets/stylesheets/bootstrap/_forms.scss b/assets/stylesheets/bootstrap/_forms.scss
index 42f2399..b0954f8 100644
--- a/assets/stylesheets/bootstrap/_forms.scss
+++ b/assets/stylesheets/bootstrap/_forms.scss
@@ -7,13 +7,13 @@
 .form-control {
   display: block;
   width: 100%;
-  padding: $input-btn-padding-y $input-btn-padding-x;
+  padding: $input-padding-y $input-padding-x;
   font-size: $font-size-base;
-  line-height: $input-btn-line-height;
+  line-height: $input-line-height;
   color: $input-color;
   background-color: $input-bg;
   background-clip: padding-box;
-  border: $input-btn-border-width solid $input-border-color;
+  border: $input-border-width solid $input-border-color;
 
   // Note: This has no effect on <select>s in some browsers, due to the limited stylability of `<select>`s in CSS.
   @if $enable-rounded {
@@ -76,6 +76,7 @@ select.form-control {
 .form-control-file,
 .form-control-range {
   display: block;
+  width: 100%;
 }
 
 
@@ -83,41 +84,28 @@ select.form-control {
 // Labels
 //
 
-// For use with horizontal and inline forms, when you need the label text to
-// align with the form controls.
+// For use with horizontal and inline forms, when you need the label (or legend)
+// text to align with the form controls.
 .col-form-label {
-  padding-top: calc(#{$input-btn-padding-y} + #{$input-btn-border-width});
-  padding-bottom: calc(#{$input-btn-padding-y} + #{$input-btn-border-width});
-  margin-bottom: 0; // Override the `<label>` default
-  line-height: $input-btn-line-height;
+  padding-top: calc(#{$input-padding-y} + #{$input-border-width});
+  padding-bottom: calc(#{$input-padding-y} + #{$input-border-width});
+  margin-bottom: 0; // Override the `<label>/<legend>` default
+  font-size: inherit; // Override the `<legend>` default
+  line-height: $input-line-height;
 }
 
 .col-form-label-lg {
-  padding-top: calc(#{$input-btn-padding-y-lg} + #{$input-btn-border-width});
-  padding-bottom: calc(#{$input-btn-padding-y-lg} + #{$input-btn-border-width});
+  padding-top: calc(#{$input-padding-y-lg} + #{$input-border-width});
+  padding-bottom: calc(#{$input-padding-y-lg} + #{$input-border-width});
   font-size: $font-size-lg;
-  line-height: $input-btn-line-height-lg;
+  line-height: $input-line-height-lg;
 }
 
 .col-form-label-sm {
-  padding-top: calc(#{$input-btn-padding-y-sm} + #{$input-btn-border-width});
-  padding-bottom: calc(#{$input-btn-padding-y-sm} + #{$input-btn-border-width});
+  padding-top: calc(#{$input-padding-y-sm} + #{$input-border-width});
+  padding-bottom: calc(#{$input-padding-y-sm} + #{$input-border-width});
   font-size: $font-size-sm;
-  line-height: $input-btn-line-height-sm;
-}
-
-
-//
-// Legends
-//
-
-// 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-btn-padding-y;
-  padding-bottom: $input-btn-padding-y;
-  margin-bottom: 0;
-  font-size: $font-size-base;
+  line-height: $input-line-height-sm;
 }
 
 
@@ -129,13 +117,13 @@ select.form-control {
 .form-control-plaintext {
   display: block;
   width: 100%;
-  padding-top: $input-btn-padding-y;
-  padding-bottom: $input-btn-padding-y;
+  padding-top: $input-padding-y;
+  padding-bottom: $input-padding-y;
   margin-bottom: 0; // match inputs if this class comes on inputs with default margins
-  line-height: $input-btn-line-height;
+  line-height: $input-line-height;
   background-color: transparent;
   border: solid transparent;
-  border-width: $input-btn-border-width 0;
+  border-width: $input-border-width 0;
 
   &.form-control-sm,
   &.form-control-lg {
@@ -154,9 +142,9 @@ select.form-control {
 // issue documented in https://github.com/twbs/bootstrap/issues/15074.
 
 .form-control-sm {
-  padding: $input-btn-padding-y-sm $input-btn-padding-x-sm;
+  padding: $input-padding-y-sm $input-padding-x-sm;
   font-size: $font-size-sm;
-  line-height: $input-btn-line-height-sm;
+  line-height: $input-line-height-sm;
   @include border-radius($input-border-radius-sm);
 }
 
@@ -167,9 +155,9 @@ select.form-control-sm {
 }
 
 .form-control-lg {
-  padding: $input-btn-padding-y-lg $input-btn-padding-x-lg;
+  padding: $input-padding-y-lg $input-padding-x-lg;
   font-size: $font-size-lg;
-  line-height: $input-btn-line-height-lg;
+  line-height: $input-line-height-lg;
   @include border-radius($input-border-radius-lg);
 }
 
@@ -220,33 +208,35 @@ select.form-control-lg {
 .form-check {
   position: relative;
   display: block;
-  margin-bottom: $form-check-margin-bottom;
-
-  &.disabled {
-    .form-check-label {
-      color: $text-muted;
-    }
-  }
-}
-
-.form-check-label {
   padding-left: $form-check-input-gutter;
-  margin-bottom: 0; // Override default `<label>` bottom margin
 }
 
 .form-check-input {
   position: absolute;
   margin-top: $form-check-input-margin-y;
   margin-left: -$form-check-input-gutter;
+
+  &:disabled ~ .form-check-label {
+    color: $text-muted;
+  }
+}
+
+.form-check-label {
+  margin-bottom: 0; // Override default `<label>` bottom margin
 }
 
-// Radios and checkboxes on same line
 .form-check-inline {
-  display: inline-block;
+  display: inline-flex;
+  align-items: center;
+  padding-left: 0; // Override base .form-check
   margin-right: $form-check-inline-margin-x;
 
-  .form-check-label {
-    vertical-align: middle;
+  // Undo .form-check-input defaults and add some `margin-right`.
+  .form-check-input {
+    position: static;
+    margin-top: 0;
+    margin-right: $form-check-inline-input-margin-x;
+    margin-left: 0;
   }
 }
 
@@ -323,10 +313,6 @@ select.form-control-lg {
       align-items: center;
       justify-content: center;
       width: auto;
-      margin-top: 0;
-      margin-bottom: 0;
-    }
-    .form-check-label {
       padding-left: 0;
     }
     .form-check-input {
@@ -336,23 +322,12 @@ select.form-control-lg {
       margin-left: 0;
     }
 
-    // Custom form controls
     .custom-control {
-      display: flex;
       align-items: center;
       justify-content: center;
-      padding-left: 0;
     }
-    .custom-control-indicator {
-      position: static;
-      display: inline-block;
-      margin-right: $form-check-input-margin-x; // Flexbox alignment means we lose our HTML space here, so we compensate.
-      vertical-align: text-bottom;
-    }
-
-    // Re-override the feedback icon.
-    .has-feedback .form-control-feedback {
-      top: 0;
+    .custom-control-label {
+      margin-bottom: 0;
     }
   }
 }
diff --git a/assets/stylesheets/bootstrap/_functions.scss b/assets/stylesheets/bootstrap/_functions.scss
index a95ad43..1266d34 100644
--- a/assets/stylesheets/bootstrap/_functions.scss
+++ b/assets/stylesheets/bootstrap/_functions.scss
@@ -56,14 +56,14 @@
 
   $yiq: (($r * 299) + ($g * 587) + ($b * 114)) / 1000;
 
-  @if ($yiq >= 150) {
+  @if ($yiq >= $yiq-contrasted-threshold) {
     @return $yiq-text-dark;
   } @else {
     @return $yiq-text-light;
   }
 }
 
-// Retreive color Sass maps
+// Retrieve color Sass maps
 @function color($key: "blue") {
   @return map-get($colors, $key);
 }
diff --git a/assets/stylesheets/bootstrap/_input-group.scss b/assets/stylesheets/bootstrap/_input-group.scss
index 9315051..7ef0267 100644
--- a/assets/stylesheets/bootstrap/_input-group.scss
+++ b/assets/stylesheets/bootstrap/_input-group.scss
@@ -7,101 +7,99 @@
 .input-group {
   position: relative;
   display: flex;
+  flex-wrap: wrap; // For form validation feedback
   align-items: stretch;
   width: 100%;
 
-  .form-control {
-    // Ensure that the input is always above the *appended* addon button for
-    // proper border colors.
-    position: relative;
-    z-index: 1;
+  .form-control,
+  .custom-select,
+  .custom-file {
+    position: relative; // For focus state's z-index
     flex: 1 1 auto;
     // Add width 1% and flex-basis auto to ensure that button will not wrap out
     // the column. Applies to IE Edge+ and Firefox. Chrome does not require this.
     width: 1%;
     margin-bottom: 0;
 
-    // Bring the "active" form control to the front
-    @include hover-focus-active {
-      z-index: 2;
+    // Bring the "active" form control to the top of surrounding elements
+    &:focus {
+      z-index: 3;
+    }
+
+    + .form-control {
+      margin-left: -$input-border-width;
     }
   }
-}
 
-.input-group-addon,
-.input-group-btn,
-.input-group .form-control,
-.input-group .custom-select,
-.input-group .custom-file {
-  display: flex;
-  align-items: center;
+  .form-control,
+  .custom-select {
+    &:not(:last-child) { @include border-right-radius(0); }
+    &:not(:first-child) { @include border-left-radius(0); }
+  }
 
-  &:not(:first-child):not(:last-child) {
-    @include border-radius(0);
+  // Custom file inputs have more complex markup, thus requiring different
+  // border-radius overrides.
+  .custom-file {
+    display: flex;
+    align-items: center;
+
+    &:not(:last-child) .custom-file-control,
+    &:not(:last-child) .custom-file-control::before { @include border-right-radius(0); }
+    &:not(:first-child) .custom-file-control,
+    &:not(:first-child) .custom-file-control::before { @include border-left-radius(0); }
   }
 }
 
-.input-group .custom-file {
+
+// Prepend and append
+//
+// While it requires one extra layer of HTML for each, dedicated prepend and
+// append elements allow us to 1) be less clever, 2) simplify our selectors, and
+// 3) support HTML5 form validation.
+
+.input-group-prepend,
+.input-group-append {
   display: flex;
   align-items: center;
-}
 
-.input-group .custom-select,
-.input-group .custom-file {
-  width: 100%;
-}
+  // Ensure buttons are always above inputs for more visually pleasing borders.
+  // This isn't needed for `.input-group-text` since it shares the same border-color
+  // as our inputs.
+  .btn {
+    position: relative;
+    z-index: 2;
+  }
 
-.input-group-addon,
-.input-group-btn {
-  white-space: nowrap;
+  .btn + .btn,
+  .btn + .input-group-text,
+  .input-group-text + .input-group-text,
+  .input-group-text + .btn {
+    margin-left: -$input-border-width;
+  }
 }
 
-// Sizing options
-//
-// Remix the default form control sizing classes into new ones for easier
-// manipulation.
-
-.input-group-lg > .form-control,
-.input-group-lg > .input-group-addon,
-.input-group-lg > .input-group-btn > .btn {
-  @extend .form-control-lg;
-}
-.input-group-sm > .form-control,
-.input-group-sm > .input-group-addon,
-.input-group-sm > .input-group-btn > .btn {
-  @extend .form-control-sm;
-}
+.input-group-prepend { margin-right: -$input-border-width; }
+.input-group-append { margin-left: -$input-border-width; }
 
 
+// Textual addons
 //
-// Text input groups
-//
+// Serves as a catch-all element for any text or radio/checkbox input you wish
+// to prepend or append to an input.
 
-.input-group-addon {
-  padding: $input-btn-padding-y $input-btn-padding-x;
+.input-group-text {
+  padding: $input-padding-y $input-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-btn-line-height;
+  line-height: $input-line-height;
   color: $input-group-addon-color;
   text-align: center;
+  white-space: nowrap;
   background-color: $input-group-addon-bg;
-  border: $input-btn-border-width solid $input-group-addon-border-color;
+  border: $input-border-width solid $input-group-addon-border-color;
   @include border-radius($input-border-radius);
 
-  // Sizing
-  &.form-control-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-btn-padding-y-lg $input-btn-padding-x-lg;
-    font-size: $font-size-lg;
-    @include border-radius($input-border-radius-lg);
-  }
-
   // Nuke default margins from checkboxes and radios to vertically center within.
   input[type="radio"],
   input[type="checkbox"] {
@@ -110,100 +108,49 @@
 }
 
 
+// Sizing
 //
-// Reset rounded corners
-//
-
-.input-group .form-control:not(:last-child),
-.input-group .custom-select:not(:last-child),
-.input-group .custom-file:not(:last-child) .custom-file-control::before,
-.input-group-addon:not(:last-child),
-.input-group-btn:not(:last-child) > .btn,
-.input-group-btn:not(:last-child) > .btn-group > .btn,
-.input-group-btn:not(:last-child) > .dropdown-toggle,
-.input-group-btn:not(:first-child) > .btn:not(:last-child):not(.dropdown-toggle),
-.input-group-btn:not(:first-child) > .btn-group:not(:last-child) > .btn {
-  @include border-right-radius(0);
-}
+// Remix the default form control sizing classes into new ones for easier
+// manipulation.
 
-.input-group-addon:not(:last-child) {
-  border-right: 0;
+.input-group-lg > .form-control,
+.input-group-lg > .input-group-prepend > .input-group-text,
+.input-group-lg > .input-group-append > .input-group-text,
+.input-group-lg > .input-group-prepend > .btn,
+.input-group-lg > .input-group-append > .btn {
+  @extend .form-control-lg;
 }
 
-.input-group .form-control:not(:first-child),
-.input-group .custom-select:not(:first-child),
-.input-group .custom-file:not(:first-child) .custom-file-control,
-.input-group-addon:not(:first-child),
-.input-group-btn:not(:first-child) > .btn,
-.input-group-btn:not(:first-child) > .btn-group > .btn,
-.input-group-btn:not(:first-child) > .dropdown-toggle,
-.input-group-btn:not(:last-child) > .btn:not(:first-child),
-.input-group-btn:not(:last-child) > .btn-group:not(:first-child) > .btn {
-  @include border-left-radius(0);
+.input-group-sm > .form-control,
+.input-group-sm > .input-group-prepend > .input-group-text,
+.input-group-sm > .input-group-append > .input-group-text,
+.input-group-sm > .input-group-prepend > .btn,
+.input-group-sm > .input-group-append > .btn {
+  @extend .form-control-sm;
 }
 
-.form-control,
-.custom-select,
-.custom-file {
-  + .input-group-addon:not(:first-child) {
-    border-left: 0;
-  }
-}
 
+// Prepend and append rounded corners
 //
-// Button input groups
-//
+// These rulesets must come after the sizing ones to properly override sm and lg
+// border-radius values when extending. They're more specific than we'd like
+// with the `.input-group >` part, but without it, we cannot override the sizing.
 
-.input-group-btn {
-  position: relative;
-  align-items: stretch;
-  // Jankily prevent input button groups from wrapping with `white-space` and
-  // `font-size` in combination with `inline-block` on buttons.
-  font-size: 0;
-  white-space: nowrap;
-
-  // Negative margin for spacing, position for bringing hovered/focused/actived
-  // element above the siblings.
-  > .btn {
-    position: relative;
-
-    + .btn {
-      margin-left: (-$input-btn-border-width);
-    }
-
-    // Bring the "active" button to the front
-    @include hover-focus-active {
-      z-index: 2;
-    }
-  }
 
-  &:first-child > .btn + .btn {
-    margin-left: 0;
-  }
+.input-group > .input-group-prepend > .btn,
+.input-group > .input-group-prepend > .input-group-text,
+.input-group > .input-group-append:not(:last-child) > .btn,
+.input-group > .input-group-append:not(:last-child) > .input-group-text,
+.input-group > .input-group-append:last-child > .btn:not(:last-child):not(.dropdown-toggle),
+.input-group > .input-group-append:last-child > .input-group-text:not(:last-child) {
+  @include border-right-radius(0);
+}
 
-  // Negative margin to only have a single, shared border between the two
-  &:not(:last-child) {
-    > .btn,
-    > .btn-group {
-      margin-right: (-$input-btn-border-width);
-    }
-  }
-  &:not(:first-child) {
-    > .btn,
-    > .btn-group {
-      z-index: 1;
-      // remove nagative margin ($input-btn-border-width) to solve overlapping issue with button.
-      margin-left: 0;
-
-      // When input is first, overlap the right side of it with the button(-group)
-      &:first-child {
-        margin-left: (-$input-btn-border-width);
-      }
-
-      // Because specificity
-      @include hover-focus-active {
-        z-index: 2;
-      }
-    }
-  }
+.input-group > .input-group-append > .btn,
+.input-group > .input-group-append > .input-group-text,
+.input-group > .input-group-prepend:not(:first-child) > .btn,
+.input-group > .input-group-prepend:not(:first-child) > .input-group-text,
+.input-group > .input-group-prepend:first-child > .btn:not(:first-child),
+.input-group > .input-group-prepend:first-child > .input-group-text:not(:first-child) {
+  @include border-left-radius(0);
 }
diff --git a/assets/stylesheets/bootstrap/_list-group.scss b/assets/stylesheets/bootstrap/_list-group.scss
index d771364..9f145c1 100644
--- a/assets/stylesheets/bootstrap/_list-group.scss
+++ b/assets/stylesheets/bootstrap/_list-group.scss
@@ -59,6 +59,7 @@
   }
 
   @include hover-focus {
+    z-index: 1; // Place hover/active items above their siblings for proper border styling
     text-decoration: none;
   }
 
@@ -70,7 +71,7 @@
 
   // Include both here for `<a>`s and `<button>`s
   &.active {
-    z-index: 1; // Place active items above their siblings for proper border styling
+    z-index: 2; // Place active items above their siblings for proper border styling
     color: $list-group-active-color;
     background-color: $list-group-active-bg;
     border-color: $list-group-active-border-color;
diff --git a/assets/stylesheets/bootstrap/_modal.scss b/assets/stylesheets/bootstrap/_modal.scss
index 5fabc83..edda836 100644
--- a/assets/stylesheets/bootstrap/_modal.scss
+++ b/assets/stylesheets/bootstrap/_modal.scss
@@ -50,11 +50,18 @@
   }
 }
 
+.modal-dialog-centered {
+  display: flex;
+  align-items: center;
+  min-height: calc(100% - (#{$modal-dialog-margin} * 2));
+}
+
 // Actual modal
 .modal-content {
   position: relative;
   display: flex;
   flex-direction: column;
+  width: 100%; // Ensure `.modal-content` extends the full width of the parent `.modal-dialog`
   // counteract the pointer-events: none; in the .modal-dialog
   pointer-events: auto;
   background-color: $modal-content-bg;
@@ -144,11 +151,16 @@
     margin: $modal-dialog-margin-y-sm-up auto;
   }
 
+  .modal-dialog-centered {
+    min-height: calc(100% - (#{$modal-dialog-margin-y-sm-up} * 2));
+  }
+
   .modal-content {
     @include box-shadow($modal-content-box-shadow-sm-up);
   }
 
   .modal-sm { max-width: $modal-sm; }
+
 }
 
 @include media-breakpoint-up(lg) {
diff --git a/assets/stylesheets/bootstrap/_nav.scss b/assets/stylesheets/bootstrap/_nav.scss
index 14e76c9..fc82161 100644
--- a/assets/stylesheets/bootstrap/_nav.scss
+++ b/assets/stylesheets/bootstrap/_nav.scss
@@ -41,7 +41,7 @@
     @include border-top-radius($nav-tabs-border-radius);
 
     @include hover-focus {
-      border-color: $nav-tabs-link-hover-border-color $nav-tabs-link-hover-border-color $nav-tabs-border-color;
+      border-color: $nav-tabs-link-hover-border-color;
     }
 
     &.disabled {
@@ -55,7 +55,7 @@
   .nav-item.show .nav-link {
     color: $nav-tabs-link-active-color;
     background-color: $nav-tabs-link-active-bg;
-    border-color: $nav-tabs-link-active-border-color $nav-tabs-link-active-border-color $nav-tabs-link-active-bg;
+    border-color: $nav-tabs-link-active-border-color;
   }
 
   .dropdown-menu {
diff --git a/assets/stylesheets/bootstrap/_navbar.scss b/assets/stylesheets/bootstrap/_navbar.scss
index 6b023e8..6b76649 100644
--- a/assets/stylesheets/bootstrap/_navbar.scss
+++ b/assets/stylesheets/bootstrap/_navbar.scss
@@ -109,13 +109,18 @@
   padding: $navbar-toggler-padding-y $navbar-toggler-padding-x;
   font-size: $navbar-toggler-font-size;
   line-height: 1;
-  background: transparent; // remove default button style
+  background-color: transparent; // remove default button style
   border: $border-width solid transparent; // remove default button style
   @include border-radius($navbar-toggler-border-radius);
 
   @include hover-focus {
     text-decoration: none;
   }
+
+  // Opinionated: add "hand" cursor to non-disabled .navbar-toggler elements
+  &:not([disabled]):not(.disabled) {
+    cursor: pointer;
+  }
 }
 
 // Keep as a separate element so folks can easily override it with another icon
diff --git a/assets/stylesheets/bootstrap/_pagination.scss b/assets/stylesheets/bootstrap/_pagination.scss
index 97977f4..286febc 100644
--- a/assets/stylesheets/bootstrap/_pagination.scss
+++ b/assets/stylesheets/bootstrap/_pagination.scss
@@ -20,6 +20,12 @@
     background-color: $pagination-hover-bg;
     border-color: $pagination-hover-border-color;
   }
+
+
+  // Opinionated: add "hand" cursor to non-disabled .page-link elements
+  &:not([disabled]):not(.disabled) {
+    cursor: pointer;
+  }
 }
 
 .page-item {
@@ -45,6 +51,8 @@
   &.disabled .page-link {
     color: $pagination-disabled-color;
     pointer-events: none;
+    // Opinionated: remove the "hand" cursor set previously for .page-link
+    cursor: auto;
     background-color: $pagination-disabled-bg;
     border-color: $pagination-disabled-border-color;
   }
diff --git a/assets/stylesheets/bootstrap/_popover.scss b/assets/stylesheets/bootstrap/_popover.scss
index 4503767..3ef5f62 100644
--- a/assets/stylesheets/bootstrap/_popover.scss
+++ b/assets/stylesheets/bootstrap/_popover.scss
@@ -8,166 +8,155 @@
   // Our parent element can be arbitrary since tooltips are by default inserted as a sibling of their target element.
   // So reset our font and text properties to avoid inheriting weird values.
   @include reset-text();
-  font-size: $font-size-sm;
+  font-size: $popover-font-size;
   // Allow breaking very long words so they don't overflow the popover's bounds
   word-wrap: break-word;
   background-color: $popover-bg;
   background-clip: padding-box;
   border: $popover-border-width solid $popover-border-color;
-  @include border-radius($border-radius-lg);
+  @include border-radius($popover-border-radius);
   @include box-shadow($popover-box-shadow);
 
-  // Arrows
-  //
-  // .arrow is outer, .arrow::after is inner
-
   .arrow {
     position: absolute;
     display: block;
     width: $popover-arrow-width;
     height: $popover-arrow-height;
+    margin: 0 $border-radius-lg;
+
+    &::before,
+    &::after {
+      position: absolute;
+      display: block;
+      content: "";
+      border-color: transparent;
+      border-style: solid;
+    }
+  }
+}
+
+.bs-popover-top {
+  margin-bottom: $popover-arrow-height;
+
+  .arrow {
+    bottom: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
   }
 
   .arrow::before,
   .arrow::after {
-    position: absolute;
-    display: block;
-    border-color: transparent;
-    border-style: solid;
+    border-width: $popover-arrow-height ($popover-arrow-width / 2) 0;
   }
 
   .arrow::before {
-    content: "";
-    border-width: $popover-arrow-width;
+    bottom: 0;
+    border-top-color: $popover-arrow-outer-color;
   }
+
   .arrow::after {
-    content: "";
-    border-width: $popover-arrow-width;
+    bottom: $popover-border-width;
+    border-top-color: $popover-arrow-color;
   }
+}
 
-  // Popover directions
-
-  &.bs-popover-top {
-    margin-bottom: $popover-arrow-width;
-
-    .arrow {
-      bottom: 0;
-    }
-
-    .arrow::before,
-    .arrow::after {
-      border-bottom-width: 0;
-    }
+.bs-popover-right {
+  margin-left: $popover-arrow-height;
 
-    .arrow::before {
-      bottom: -$popover-arrow-width;
-      margin-left: -$popover-arrow-width;
-      border-top-color: $popover-arrow-outer-color;
-    }
-
-    .arrow::after {
-      bottom: calc((#{$popover-arrow-width} - #{$popover-border-width}) * -1);
-      margin-left: -$popover-arrow-width;
-      border-top-color: $popover-arrow-color;
-    }
+  .arrow {
+    left: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
+    width: $popover-arrow-height;
+    height: $popover-arrow-width;
+    margin: $border-radius-lg 0; // make sure the arrow does not touch the popover's rounded corners
   }
 
-  &.bs-popover-right {
-    margin-left: $popover-arrow-width;
+  .arrow::before,
+  .arrow::after {
+    border-width: ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2) 0;
+  }
 
-    .arrow {
-      left: 0;
-    }
+  .arrow::before {
+    left: 0;
+    border-right-color: $popover-arrow-outer-color;
+  }
 
-    .arrow::before,
-    .arrow::after {
-      margin-top: -$popover-arrow-width;
-      border-left-width: 0;
-    }
+  .arrow::after {
+    left: $popover-border-width;
+    border-right-color: $popover-arrow-color;
+  }
+}
 
-    .arrow::before {
-      left: -$popover-arrow-width;
-      border-right-color: $popover-arrow-outer-color;
-    }
+.bs-popover-bottom {
+  margin-top: $popover-arrow-height;
 
-    .arrow::after {
-      left: calc((#{$popover-arrow-width} - #{$popover-border-width}) * -1);
-      border-right-color: $popover-arrow-color;
-    }
+  .arrow {
+    top: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
   }
 
-  &.bs-popover-bottom {
-    margin-top: $popover-arrow-width;
+  .arrow::before,
+  .arrow::after {
+    border-width: 0 ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2);
+  }
 
-    .arrow {
-      top: 0;
-    }
+  .arrow::before {
+    top: 0;
+    border-bottom-color: $popover-arrow-outer-color;
+  }
 
-    .arrow::before,
-    .arrow::after {
-      margin-left: -$popover-arrow-width;
-      border-top-width: 0;
-    }
+  .arrow::after {
+    top: $popover-border-width;
+    border-bottom-color: $popover-arrow-color;
+  }
 
-    .arrow::before {
-      top: -$popover-arrow-width;
-      border-bottom-color: $popover-arrow-outer-color;
-    }
+  // This will remove the popover-header's border just below the arrow
+  .popover-header::before {
+    position: absolute;
+    top: 0;
+    left: 50%;
+    display: block;
+    width: $popover-arrow-width;
+    margin-left: ($popover-arrow-width / -2);
+    content: "";
+    border-bottom: $popover-border-width solid $popover-header-bg;
+  }
+}
 
-    .arrow::after {
-      top: calc((#{$popover-arrow-width} - #{$popover-border-width}) * -1);
-      border-bottom-color: $popover-arrow-color;
-    }
+.bs-popover-left {
+  margin-right: $popover-arrow-height;
 
-    // This will remove the popover-header's border just below the arrow
-    .popover-header::before {
-      position: absolute;
-      top: 0;
-      left: 50%;
-      display: block;
-      width: 20px;
-      margin-left: -10px;
-      content: "";
-      border-bottom: $popover-border-width solid $popover-header-bg;
-    }
+  .arrow {
+    right: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
+    width: $popover-arrow-height;
+    height: $popover-arrow-width;
+    margin: $border-radius-lg 0; // make sure the arrow does not touch the popover's rounded corners
   }
 
-  &.bs-popover-left {
-    margin-right: $popover-arrow-width;
-
-    .arrow {
-      right: 0;
-    }
+  .arrow::before,
+  .arrow::after {
+    border-width: ($popover-arrow-width / 2) 0 ($popover-arrow-width / 2) $popover-arrow-height;
+  }
 
-    .arrow::before,
-    .arrow::after {
-      margin-top: -$popover-arrow-width;
-      border-right-width: 0;
-    }
+  .arrow::before {
+    right: 0;
+    border-left-color: $popover-arrow-outer-color;
+  }
 
-    .arrow::before {
-      right: -$popover-arrow-width;
-      border-left-color: $popover-arrow-outer-color;
-    }
+  .arrow::after {
+    right: $popover-border-width;
+    border-left-color: $popover-arrow-color;
+  }
+}
 
-    .arrow::after {
-      right: calc((#{$popover-arrow-width} - #{$popover-border-width}) * -1);
-      border-left-color: $popover-arrow-color;
-    }
+.bs-popover-auto {
+  &[x-placement^="top"] {
+    @extend .bs-popover-top;
   }
-  &.bs-popover-auto {
-    &[x-placement^="top"] {
-      @extend .bs-popover-top;
-    }
-    &[x-placement^="right"] {
-      @extend .bs-popover-right;
-    }
-    &[x-placement^="bottom"] {
-      @extend .bs-popover-bottom;
-    }
-    &[x-placement^="left"] {
-      @extend .bs-popover-left;
-    }
+  &[x-placement^="right"] {
+    @extend .bs-popover-right;
+  }
+  &[x-placement^="bottom"] {
+    @extend .bs-popover-bottom;
+  }
+  &[x-placement^="left"] {
+    @extend .bs-popover-left;
   }
 }
 
diff --git a/assets/stylesheets/bootstrap/_progress.scss b/assets/stylesheets/bootstrap/_progress.scss
index efbb440..a581116 100644
--- a/assets/stylesheets/bootstrap/_progress.scss
+++ b/assets/stylesheets/bootstrap/_progress.scss
@@ -10,14 +10,17 @@
   font-size: $progress-font-size;
   background-color: $progress-bg;
   @include border-radius($progress-border-radius);
+  @include box-shadow($progress-box-shadow);
 }
 
 .progress-bar {
   display: flex;
-  align-items: center;
+  flex-direction: column;
   justify-content: center;
   color: $progress-bar-color;
+  text-align: center;
   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 f98a719..5393413 100644
--- a/assets/stylesheets/bootstrap/_reboot.scss
+++ b/assets/stylesheets/bootstrap/_reboot.scss
@@ -71,7 +71,7 @@ body {
 //
 // Credit: https://github.com/suitcss/base
 [tabindex="-1"]:focus {
-  outline: none !important;
+  outline: 0 !important;
 }
 
 
@@ -491,6 +491,7 @@ output {
 
 summary {
   display: list-item; // Add the correct display in all browsers
+  cursor: pointer;
 }
 
 template {
diff --git a/assets/stylesheets/bootstrap/_tables.scss b/assets/stylesheets/bootstrap/_tables.scss
index 6bd0b91..0e3b119 100644
--- a/assets/stylesheets/bootstrap/_tables.scss
+++ b/assets/stylesheets/bootstrap/_tables.scss
@@ -171,7 +171,7 @@
         -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 {
+        > .table-bordered {
           border: 0;
         }
       }
diff --git a/assets/stylesheets/bootstrap/_tooltip.scss b/assets/stylesheets/bootstrap/_tooltip.scss
index 7b5db1c..1286ebf 100644
--- a/assets/stylesheets/bootstrap/_tooltip.scss
+++ b/assets/stylesheets/bootstrap/_tooltip.scss
@@ -7,7 +7,7 @@
   // Our parent element can be arbitrary since tooltips are by default inserted as a sibling of their target element.
   // So reset our font and text properties to avoid inheriting weird values.
   @include reset-text();
-  font-size: $font-size-sm;
+  font-size: $tooltip-font-size;
   // Allow breaking very long words so they don't overflow the tooltip's bounds
   word-wrap: break-word;
   opacity: 0;
@@ -19,80 +19,88 @@
     display: block;
     width: $tooltip-arrow-width;
     height: $tooltip-arrow-height;
-  }
 
-  .arrow::before {
-    position: absolute;
-    border-color: transparent;
-    border-style: solid;
+    &::before {
+      position: absolute;
+      content: "";
+      border-color: transparent;
+      border-style: solid;
+    }
   }
+}
 
-  &.bs-tooltip-top {
-    padding: $tooltip-arrow-width 0;
-    .arrow {
-      bottom: 0;
-    }
+.bs-tooltip-top {
+  padding: $tooltip-arrow-height 0;
 
-    .arrow::before {
-      margin-left: -($tooltip-arrow-width - 2);
-      content: "";
-      border-width: $tooltip-arrow-width $tooltip-arrow-width 0;
+  .arrow {
+    bottom: 0;
+
+    &::before {
+      top: 0;
+      border-width: $tooltip-arrow-height ($tooltip-arrow-width / 2) 0;
       border-top-color: $tooltip-arrow-color;
     }
   }
-  &.bs-tooltip-right {
-    padding: 0 $tooltip-arrow-width;
-    .arrow {
-      left: 0;
-    }
+}
 
-    .arrow::before {
-      margin-top: -($tooltip-arrow-width - 2);
-      content: "";
-      border-width: $tooltip-arrow-width $tooltip-arrow-width $tooltip-arrow-width 0;
+.bs-tooltip-right {
+  padding: 0 $tooltip-arrow-height;
+
+  .arrow {
+    left: 0;
+    width: $tooltip-arrow-height;
+    height: $tooltip-arrow-width;
+
+    &::before {
+      right: 0;
+      border-width: ($tooltip-arrow-width / 2) $tooltip-arrow-height ($tooltip-arrow-width / 2) 0;
       border-right-color: $tooltip-arrow-color;
     }
   }
-  &.bs-tooltip-bottom {
-    padding: $tooltip-arrow-width 0;
-    .arrow {
-      top: 0;
-    }
+}
 
-    .arrow::before {
-      margin-left: -($tooltip-arrow-width - 2);
-      content: "";
-      border-width: 0 $tooltip-arrow-width $tooltip-arrow-width;
+.bs-tooltip-bottom {
+  padding: $tooltip-arrow-height 0;
+
+  .arrow {
+    top: 0;
+
+    &::before {
+      bottom: 0;
+      border-width: 0 ($tooltip-arrow-width / 2) $tooltip-arrow-height;
       border-bottom-color: $tooltip-arrow-color;
     }
   }
-  &.bs-tooltip-left {
-    padding: 0 $tooltip-arrow-width;
-    .arrow {
-      right: 0;
-    }
+}
 
-    .arrow::before {
-      right: 0;
-      margin-top: -($tooltip-arrow-width - 2);
-      content: "";
-      border-width: $tooltip-arrow-width 0 $tooltip-arrow-width $tooltip-arrow-width;
+.bs-tooltip-left {
+  padding: 0 $tooltip-arrow-height;
+
+  .arrow {
+    right: 0;
+    width: $tooltip-arrow-height;
+    height: $tooltip-arrow-width;
+
+    &::before {
+      left: 0;
+      border-width: ($tooltip-arrow-width / 2) 0 ($tooltip-arrow-width / 2) $tooltip-arrow-height;
       border-left-color: $tooltip-arrow-color;
     }
   }
-  &.bs-tooltip-auto {
-    &[x-placement^="top"] {
-      @extend .bs-tooltip-top;
-    }
-    &[x-placement^="right"] {
-      @extend .bs-tooltip-right;
-    }
-    &[x-placement^="bottom"] {
-      @extend .bs-tooltip-bottom;
-    }
-    &[x-placement^="left"] {
-      @extend .bs-tooltip-left;
-    }
+}
+
+.bs-tooltip-auto {
+  &[x-placement^="top"] {
+    @extend .bs-tooltip-top;
+  }
+  &[x-placement^="right"] {
+    @extend .bs-tooltip-right;
+  }
+  &[x-placement^="bottom"] {
+    @extend .bs-tooltip-bottom;
+  }
+  &[x-placement^="left"] {
+    @extend .bs-tooltip-left;
   }
 }
 
@@ -103,5 +111,5 @@
   color: $tooltip-color;
   text-align: center;
   background-color: $tooltip-bg;
-  @include border-radius($border-radius);
+  @include border-radius($tooltip-border-radius);
 }
diff --git a/assets/stylesheets/bootstrap/_type.scss b/assets/stylesheets/bootstrap/_type.scss
index b1b8f61..57d610f 100644
--- a/assets/stylesheets/bootstrap/_type.scss
+++ b/assets/stylesheets/bootstrap/_type.scss
@@ -53,8 +53,8 @@ h6, .h6 { font-size: $h6-font-size; }
 //
 
 hr {
-  margin-top: 1rem;
-  margin-bottom: 1rem;
+  margin-top: $hr-margin-y;
+  margin-bottom: $hr-margin-y;
   border: 0;
   border-top: $hr-border-width solid $hr-border-color;
 }
diff --git a/assets/stylesheets/bootstrap/_variables.scss b/assets/stylesheets/bootstrap/_variables.scss
index 50972c5..26b44e9 100644
--- a/assets/stylesheets/bootstrap/_variables.scss
+++ b/assets/stylesheets/bootstrap/_variables.scss
@@ -87,10 +87,12 @@ $theme-colors: map-merge((
 // Set a specific jump point for requesting color jumps
 $theme-color-interval:      8% !default;
 
-// Customize the light and dark text colors for use in our YIQ color contrast function.
-$yiq-text-dark: #111 !default;
-$yiq-text-light: #fff !default;
+// The yiq lightness value that determines when the lightness of color changes from "dark" to "light". Acceptable values are between 0 and 255.
+$yiq-contrasted-threshold: 150 !default;
 
+// Customize the light and dark text colors for use in our YIQ color contrast function.
+$yiq-text-dark: $gray-900 !default;
+$yiq-text-light: $white !default;
 
 // Options
 //
@@ -221,7 +223,7 @@ $transition-collapse:         height .35s ease !default;
 
 // stylelint-disable value-keyword-case
 $font-family-sans-serif:      -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol" !default;
-$font-family-monospace:       "SFMono-Regular", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
+$font-family-monospace:       SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
 $font-family-base:            $font-family-sans-serif !default;
 // stylelint-enable value-keyword-case
 
@@ -280,9 +282,11 @@ $dt-font-weight:              $font-weight-bold !default;
 $kbd-box-shadow:              inset 0 -.1rem 0 rgba($black, .25) !default;
 $nested-kbd-font-weight:      $font-weight-bold !default;
 
-$list-inline-padding:         5px !default;
+$list-inline-padding:         .5rem !default;
+
+$mark-bg:                     #fcf8e3 !default;
 
-$mark-bg: #fcf8e3 !default;
+$hr-margin-y:                 $spacer !default;
 
 
 // Tables
@@ -298,7 +302,7 @@ $table-hover-bg:              rgba($black, .075) !default;
 $table-active-bg:             $table-hover-bg !default;
 
 $table-border-width:          $border-width !default;
-$table-border-color:          $gray-200 !default;
+$table-border-color:          $gray-300 !default;
 
 $table-head-bg:               $gray-200 !default;
 $table-head-color:            $gray-700 !default;
@@ -310,9 +314,9 @@ $table-dark-border-color:     lighten($gray-900, 7.5%) !default;
 $table-dark-color:            $body-bg !default;
 
 
-// Buttons
+// Buttons + Forms
 //
-// For each of Bootstrap's buttons, define text, background and border color.
+// Shared variables that are reassigned to `$input-` and `$btn-` specific variables.
 
 $input-btn-padding-y:         .375rem !default;
 $input-btn-padding-x:         .75rem !default;
@@ -330,8 +334,32 @@ $input-btn-padding-y-lg:      .5rem !default;
 $input-btn-padding-x-lg:      1rem !default;
 $input-btn-line-height-lg:    $line-height-lg !default;
 
+$input-btn-border-width:      $border-width !default;
+
+
+// Buttons
+//
+// For each of Bootstrap's buttons, define text, background, and border color.
+
+$btn-padding-y:               $input-btn-padding-y !default;
+$btn-padding-x:               $input-btn-padding-x !default;
+$btn-line-height:             $input-btn-line-height !default;
+
+$btn-padding-y-sm:            $input-btn-padding-y-sm !default;
+$btn-padding-x-sm:            $input-btn-padding-x-sm !default;
+$btn-line-height-sm:          $input-btn-line-height-sm !default;
+
+$btn-padding-y-lg:            $input-btn-padding-y-lg !default;
+$btn-padding-x-lg:            $input-btn-padding-x-lg !default;
+$btn-line-height-lg:          $input-btn-line-height-lg !default;
+
+$btn-border-width:            $input-btn-border-width !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-width:             $input-btn-focus-width !default;
+$btn-focus-box-shadow:        $input-btn-focus-box-shadow !default;
+$btn-disabled-opacity:        .65 !default;
 $btn-active-box-shadow:       inset 0 3px 5px rgba($black, .125) !default;
 
 $btn-link-disabled-color:     $gray-600 !default;
@@ -348,12 +376,24 @@ $btn-transition:              color .15s ease-in-out, background-color .15s ease
 
 // Forms
 
+$input-padding-y:                       $input-btn-padding-y !default;
+$input-padding-x:                       $input-btn-padding-x !default;
+$input-line-height:                     $input-btn-line-height !default;
+
+$input-padding-y-sm:                    $input-btn-padding-y-sm !default;
+$input-padding-x-sm:                    $input-btn-padding-x-sm !default;
+$input-line-height-sm:                  $input-btn-line-height-sm !default;
+
+$input-padding-y-lg:                    $input-btn-padding-y-lg !default;
+$input-padding-x-lg:                    $input-btn-padding-x-lg !default;
+$input-line-height-lg:                  $input-btn-line-height-lg !default;
+
 $input-bg:                              $white !default;
 $input-disabled-bg:                     $gray-200 !default;
 
 $input-color:                           $gray-700 !default;
 $input-border-color:                    $gray-400 !default;
-$input-btn-border-width:                $border-width !default; // For form controls and buttons
+$input-border-width:                    $input-btn-border-width !default;
 $input-box-shadow:                      inset 0 1px 1px rgba($black, .075) !default;
 
 $input-border-radius:                   $border-radius !default;
@@ -363,6 +403,8 @@ $input-border-radius-sm:                $border-radius-sm !default;
 $input-focus-bg:                        $input-bg !default;
 $input-focus-border-color:              lighten(theme-color("primary"), 25%) !default;
 $input-focus-color:                     $input-color !default;
+$input-focus-width:                     $input-btn-focus-width !default;
+$input-focus-box-shadow:                $input-btn-focus-box-shadow !default;
 
 $input-placeholder-color:               $gray-600 !default;
 
@@ -377,16 +419,16 @@ $input-height-sm:                       calc(#{$input-height-inner-sm} + #{$inpu
 $input-height-inner-lg:                 ($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;
 
-$input-transition:                      border-color ease-in-out .15s, box-shadow ease-in-out .15s !default;
+$input-transition:                      border-color .15s ease-in-out, box-shadow .15s ease-in-out !default;
 
 $form-text-margin-top:                  .25rem !default;
 
-$form-check-margin-bottom:              .5rem !default;
 $form-check-input-gutter:               1.25rem !default;
-$form-check-input-margin-y:             .25rem !default;
+$form-check-input-margin-y:             .3rem !default;
 $form-check-input-margin-x:             .25rem !default;
 
 $form-check-inline-margin-x:            .75rem !default;
+$form-check-inline-input-margin-x:      .3125rem !default;
 
 $form-group-margin-bottom:              1rem !default;
 
@@ -395,16 +437,15 @@ $input-group-addon-bg:                  $gray-200 !default;
 $input-group-addon-border-color:        $input-border-color !default;
 
 $custom-control-gutter:                 1.5rem !default;
-$custom-control-spacer-y:               .25rem !default;
 $custom-control-spacer-x:               1rem !default;
 
 $custom-control-indicator-size:         1rem !default;
-$custom-control-indicator-bg:           #ddd !default;
+$custom-control-indicator-bg:           $gray-300 !default;
 $custom-control-indicator-bg-size:      50% 50% !default;
 $custom-control-indicator-box-shadow:   inset 0 .25rem .25rem rgba($black, .1) !default;
 
 $custom-control-indicator-disabled-bg:          $gray-200 !default;
-$custom-control-description-disabled-color:     $gray-600 !default;
+$custom-control-label-disabled-color:     $gray-600 !default;
 
 $custom-control-indicator-checked-color:        $white !default;
 $custom-control-indicator-checked-bg:           theme-color("primary") !default;
@@ -437,21 +478,24 @@ $custom-select-disabled-color:      $gray-600 !default;
 $custom-select-bg:                  $white !default;
 $custom-select-disabled-bg:         $gray-200 !default;
 $custom-select-bg-size:             8px 10px !default; // In pixels because image dimensions
-$custom-select-indicator-color:     #333 !default;
+$custom-select-indicator-color:     $gray-800 !default;
 $custom-select-indicator:           str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 5'%3E%3Cpath fill='#{$custom-select-indicator-color}' d='M2 0L0 2h4zm0 5L0 3h4z'/%3E%3C/svg%3E"), "#", "%23") !default;
 $custom-select-border-width:        $input-btn-border-width !default;
 $custom-select-border-color:        $input-border-color !default;
 $custom-select-border-radius:       $border-radius !default;
 
-$custom-select-focus-border-color:  lighten(theme-color("primary"), 25%) !default;
-$custom-select-focus-box-shadow:    inset 0 1px 2px rgba($black, .075), 0 0 5px rgba($custom-select-focus-border-color, .5) !default;
+$custom-select-focus-border-color:  $input-focus-border-color !default;
+$custom-select-focus-box-shadow:    inset 0 1px 2px rgba($black, .075), $input-btn-focus-box-shadow !default;
 
 $custom-select-font-size-sm:        75% !default;
 $custom-select-height-sm:           $input-height-sm !default;
 
+$custom-select-font-size-lg:        125% !default;
+$custom-select-height-lg:           $input-height-lg !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-focus-border-color:    $input-focus-border-color !default;
+$custom-file-focus-box-shadow:      $input-btn-focus-box-shadow !default;
 
 $custom-file-padding-y:             $input-btn-padding-y !default;
 $custom-file-padding-x:             $input-btn-padding-x !default;
@@ -465,16 +509,13 @@ $custom-file-box-shadow:            $input-box-shadow !default;
 $custom-file-button-color:          $custom-file-color !default;
 $custom-file-button-bg:             $input-group-addon-bg !default;
 $custom-file-text: (
-  placeholder: (
-    en: "Choose file..."
-  ),
-  button-label: (
-    en: "Browse"
-  )
+  en: "Browse"
 ) !default;
 
 
 // Form validation
+$form-feedback-margin-top:          $form-text-margin-top !default;
+$form-feedback-font-size:           $small-font-size !default;
 $form-feedback-valid-color:         theme-color("success") !default;
 $form-feedback-invalid-color:       theme-color("danger") !default;
 
@@ -527,13 +568,13 @@ $nav-link-padding-y:                .5rem !default;
 $nav-link-padding-x:                1rem !default;
 $nav-link-disabled-color:           $gray-600 !default;
 
-$nav-tabs-border-color:             #ddd !default;
+$nav-tabs-border-color:             $gray-300 !default;
 $nav-tabs-border-width:             $border-width !default;
 $nav-tabs-border-radius:            $border-radius !default;
-$nav-tabs-link-hover-border-color:  $gray-200 !default;
+$nav-tabs-link-hover-border-color:  $gray-200 $gray-200 $nav-tabs-border-color !default;
 $nav-tabs-link-active-color:        $gray-700 !default;
 $nav-tabs-link-active-bg:           $body-bg !default;
-$nav-tabs-link-active-border-color: #ddd !default;
+$nav-tabs-link-active-border-color: $gray-300 $gray-300 $nav-tabs-link-active-bg !default;
 
 $nav-pills-border-radius:           $border-radius !default;
 $nav-pills-link-active-color:       $component-active-color !default;
@@ -582,11 +623,11 @@ $pagination-line-height:            1.25 !default;
 $pagination-color:                  $link-color !default;
 $pagination-bg:                     $white !default;
 $pagination-border-width:           $border-width !default;
-$pagination-border-color:           #ddd !default;
+$pagination-border-color:           $gray-300 !default;
 
 $pagination-hover-color:            $link-hover-color !default;
 $pagination-hover-bg:               $gray-200 !default;
-$pagination-hover-border-color:     #ddd !default;
+$pagination-hover-border-color:     $gray-300 !default;
 
 $pagination-active-color:           $white !default;
 $pagination-active-bg:              theme-color("primary") !default;
@@ -594,7 +635,7 @@ $pagination-active-border-color:    theme-color("primary") !default;
 
 $pagination-disabled-color:         $gray-600 !default;
 $pagination-disabled-bg:            $white !default;
-$pagination-disabled-border-color:  #ddd !default;
+$pagination-disabled-border-color:  $gray-300 !default;
 
 
 // Jumbotron
@@ -626,26 +667,29 @@ $card-columns-margin:               $card-spacer-y !default;
 
 // Tooltips
 
-$tooltip-max-width:                 200px !default;
-$tooltip-color:                     $white !default;
-$tooltip-bg:                        $black !default;
-$tooltip-opacity:                   .9 !default;
-$tooltip-padding-y:                 3px !default;
-$tooltip-padding-x:                 8px !default;
-$tooltip-margin:                    0 !default;
+$tooltip-font-size:           $font-size-sm !default;
+$tooltip-max-width:           200px !default;
+$tooltip-color:               $white !default;
+$tooltip-bg:                  $black !default;
+$tooltip-border-radius:        $border-radius !default;
+$tooltip-opacity:             .9 !default;
+$tooltip-padding-y:           .25rem !default;
+$tooltip-padding-x:           .5rem !default;
+$tooltip-margin:              0 !default;
 
-
-$tooltip-arrow-width:               5px !default;
-$tooltip-arrow-height:              5px !default;
-$tooltip-arrow-color:               $tooltip-bg !default;
+$tooltip-arrow-width:         .8rem !default;
+$tooltip-arrow-height:        .4rem !default;
+$tooltip-arrow-color:         $tooltip-bg !default;
 
 
 // Popovers
 
+$popover-font-size:                 $font-size-sm !default;
 $popover-bg:                        $white !default;
 $popover-max-width:                 276px !default;
 $popover-border-width:              $border-width !default;
 $popover-border-color:              rgba($black, .2) !default;
+$popover-border-radius:             $border-radius-lg !default;
 $popover-box-shadow:                0 .25rem .5rem rgba($black, .2) !default;
 
 $popover-header-bg:                 darken($popover-bg, 3%) !default;
@@ -657,8 +701,8 @@ $popover-body-color:                $body-color !default;
 $popover-body-padding-y:            $popover-header-padding-y !default;
 $popover-body-padding-x:            $popover-header-padding-x !default;
 
-$popover-arrow-width:               .8rem !default;
-$popover-arrow-height:              .4rem !default;
+$popover-arrow-width:               1rem !default;
+$popover-arrow-height:              .5rem !default;
 $popover-arrow-color:               $popover-bg !default;
 
 $popover-arrow-outer-color:         fade-in($popover-border-color, .05) !default;
@@ -681,26 +725,26 @@ $badge-pill-border-radius:          10rem !default;
 // Modals
 
 // Padding applied to the modal body
-$modal-inner-padding:               15px !default;
+$modal-inner-padding:         1rem !default;
 
-$modal-dialog-margin:               10px !default;
-$modal-dialog-margin-y-sm-up:       30px !default;
+$modal-dialog-margin:         .5rem !default;
+$modal-dialog-margin-y-sm-up: 1.75rem !default;
 
 $modal-title-line-height:           $line-height-base !default;
 
-$modal-content-bg:                  $white !default;
-$modal-content-border-color:        rgba($black, .2) !default;
-$modal-content-border-width:        $border-width !default;
-$modal-content-box-shadow-xs:       0 3px 9px rgba($black, .5) !default;
-$modal-content-box-shadow-sm-up:    0 5px 15px rgba($black, .5) !default;
+$modal-content-bg:               $white !default;
+$modal-content-border-color:     rgba($black, .2) !default;
+$modal-content-border-width:     $border-width !default;
+$modal-content-box-shadow-xs:    0 .25rem .5rem rgba($black, .5) !default;
+$modal-content-box-shadow-sm-up: 0 .5rem 1rem rgba($black, .5) !default;
 
-$modal-backdrop-bg:                 $black !default;
-$modal-backdrop-opacity:            .5 !default;
-$modal-header-border-color:         $gray-200 !default;
-$modal-footer-border-color:         $modal-header-border-color !default;
-$modal-header-border-width:         $modal-content-border-width !default;
-$modal-footer-border-width:         $modal-header-border-width !default;
-$modal-header-padding:              15px !default;
+$modal-backdrop-bg:           $black !default;
+$modal-backdrop-opacity:      .5 !default;
+$modal-header-border-color:   $gray-200 !default;
+$modal-footer-border-color:   $modal-header-border-color !default;
+$modal-header-border-width:   $modal-content-border-width !default;
+$modal-footer-border-width:   $modal-header-border-width !default;
+$modal-header-padding:        1rem !default;
 
 $modal-lg:                          800px !default;
 $modal-md:                          500px !default;
@@ -720,6 +764,10 @@ $alert-border-radius:               $border-radius !default;
 $alert-link-font-weight:            $font-weight-bold !default;
 $alert-border-width:                $border-width !default;
 
+$alert-bg-level:                    -10 !default;
+$alert-border-level:                -9 !default;
+$alert-color-level:                 6 !default;
+
 
 // Progress bars
 
@@ -763,7 +811,7 @@ $list-group-action-active-bg:       $gray-200 !default;
 $thumbnail-padding:                 .25rem !default;
 $thumbnail-bg:                      $body-bg !default;
 $thumbnail-border-width:            $border-width !default;
-$thumbnail-border-color:            #ddd !default;
+$thumbnail-border-color:            $gray-300 !default;
 $thumbnail-border-radius:           $border-radius !default;
 $thumbnail-box-shadow:              0 1px 2px rgba($black, .075) !default;
 
@@ -819,12 +867,12 @@ $close-text-shadow:                 0 1px 0 $white !default;
 
 // Code
 
-$code-font-size:                    90% !default;
-$code-padding-y:                    .2rem !default;
-$code-padding-x:                    .4rem !default;
-$code-color:                        #bd4147 !default;
-$code-bg:                           $gray-100 !default;
+$code-font-size:                    87.5% !default;
+$code-color:                        $pink !default;
 
+$kbd-padding-y:                     .2rem !default;
+$kbd-padding-x:                     .4rem !default;
+$kbd-font-size:                     $code-font-size !default;
 $kbd-color:                         $white !default;
 $kbd-bg:                            $gray-900 !default;
 
diff --git a/assets/stylesheets/bootstrap/mixins/_background-variant.scss b/assets/stylesheets/bootstrap/mixins/_background-variant.scss
index 7d1bc97..494439d 100644
--- a/assets/stylesheets/bootstrap/mixins/_background-variant.scss
+++ b/assets/stylesheets/bootstrap/mixins/_background-variant.scss
@@ -6,7 +6,8 @@
   #{$parent} {
     background-color: $color !important;
   }
-  a#{$parent} {
+  a#{$parent},
+  button#{$parent} {
     @include hover-focus {
       background-color: darken($color, 10%) !important;
     }
diff --git a/assets/stylesheets/bootstrap/mixins/_breakpoints.scss b/assets/stylesheets/bootstrap/mixins/_breakpoints.scss
index a9866bd..7c95c68 100644
--- a/assets/stylesheets/bootstrap/mixins/_breakpoints.scss
+++ b/assets/stylesheets/bootstrap/mixins/_breakpoints.scss
@@ -29,13 +29,15 @@
 }
 
 // Maximum breakpoint width. Null for the largest (last) breakpoint.
-// The maximum value is calculated as the minimum of the next one less 0.1.
+// The maximum value is calculated as the minimum of the next one less 0.01px
+// to work around the limitations of `min-` and `max-` prefixes and viewports with fractional widths.
+// See https://www.w3.org/TR/mediaqueries-4/#mq-min-max
 //
 //    >> breakpoint-max(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
 //    767px
 @function breakpoint-max($name, $breakpoints: $grid-breakpoints) {
   $next: breakpoint-next($name, $breakpoints);
-  @return if($next, breakpoint-min($next, $breakpoints) - 1px, null);
+  @return if($next, breakpoint-min($next, $breakpoints) - .01px, null);
 }
 
 // Returns a blank string if smallest breakpoint, otherwise returns the name with a dash infront.
diff --git a/assets/stylesheets/bootstrap/mixins/_buttons.scss b/assets/stylesheets/bootstrap/mixins/_buttons.scss
index 9e06261..252e26a 100644
--- a/assets/stylesheets/bootstrap/mixins/_buttons.scss
+++ b/assets/stylesheets/bootstrap/mixins/_buttons.scss
@@ -19,9 +19,9 @@
   &.focus {
     // Avoid using mixin so we can pass custom focus shadow properly
     @if $enable-shadows {
-      box-shadow: $btn-box-shadow, 0 0 0 $input-btn-focus-width rgba($border, .5);
+      box-shadow: $btn-box-shadow, 0 0 0 $btn-focus-width rgba($border, .5);
     } @else {
-      box-shadow: 0 0 0 $input-btn-focus-width rgba($border, .5);
+      box-shadow: 0 0 0 $btn-focus-width rgba($border, .5);
     }
   }
 
@@ -42,30 +42,32 @@
     }
     border-color: $active-border;
 
-    // Avoid using mixin so we can pass custom focus shadow properly
-    @if $enable-shadows {
-      box-shadow: $btn-active-box-shadow, 0 0 0 $input-btn-focus-width rgba($border, .5);
-    } @else {
-      box-shadow: 0 0 0 $input-btn-focus-width rgba($border, .5);
+    &:focus {
+      // Avoid using mixin so we can pass custom focus shadow properly
+      @if $enable-shadows {
+        box-shadow: $btn-active-box-shadow, 0 0 0 $btn-focus-width rgba($border, .5);
+      } @else {
+        box-shadow: 0 0 0 $btn-focus-width rgba($border, .5);
+      }
     }
   }
 }
 
-@mixin button-outline-variant($color, $color-hover: #fff) {
+@mixin button-outline-variant($color, $color-hover: #fff, $active-background: $color, $active-border: $color) {
   color: $color;
   background-color: transparent;
   background-image: none;
   border-color: $color;
 
-  @include hover {
-    color: $color-hover;
-    background-color: $color;
-    border-color: $color;
+  &:hover {
+    color: color-yiq($color);
+    background-color: $active-background;
+    border-color: $active-border;
   }
 
   &:focus,
   &.focus {
-    box-shadow: 0 0 0 $input-btn-focus-width rgba($color, .5);
+    box-shadow: 0 0 0 $btn-focus-width rgba($color, .5);
   }
 
   &.disabled,
@@ -77,11 +79,11 @@
   &:not([disabled]):not(.disabled):active,
   &:not([disabled]):not(.disabled).active,
   .show > &.dropdown-toggle {
-    color: $color-hover;
-    background-color: $color;
-    border-color: $color;
+    color: color-yiq($color-hover);
+    background-color: $active-background;
+    border-color: $active-border;
     // Avoid using mixin so we can pass custom focus shadow properly
-    box-shadow: 0 0 0 $input-btn-focus-width rgba($color, .5);
+    box-shadow: 0 0 0 $btn-focus-width rgba($color, .5);
   }
 }
 
@@ -90,5 +92,10 @@
   padding: $padding-y $padding-x;
   font-size: $font-size;
   line-height: $line-height;
-  @include border-radius($border-radius);
+  // Manually declare to provide an override to the browser default
+  @if $enable-rounded {
+    border-radius: $border-radius;
+  } @else {
+    border-radius: 0;
+  }
 }
diff --git a/assets/stylesheets/bootstrap/mixins/_caret.scss b/assets/stylesheets/bootstrap/mixins/_caret.scss
index daab9d0..40478e4 100644
--- a/assets/stylesheets/bootstrap/mixins/_caret.scss
+++ b/assets/stylesheets/bootstrap/mixins/_caret.scss
@@ -12,6 +12,18 @@
   border-left: $caret-width solid transparent;
 }
 
+@mixin caret-right {
+  border-top: $caret-width solid transparent;
+  border-bottom: $caret-width solid transparent;
+  border-left: $caret-width solid;
+}
+
+@mixin caret-left {
+  border-top: $caret-width solid transparent;
+  border-right: $caret-width solid;
+  border-bottom: $caret-width solid transparent;
+}
+
 @mixin caret($direction: down) {
   @if $enable-caret {
     &::after {
@@ -25,6 +37,24 @@
         @include caret-down;
       } @else if $direction == up {
         @include caret-up;
+      } @else if $direction == right {
+        @include caret-right;
+      }
+    }
+
+    @if $direction == left {
+      &::after {
+        display: none;
+      }
+
+      &::before {
+        display: inline-block;
+        width: 0;
+        height: 0;
+        margin-right: $caret-width * .85;
+        vertical-align: $caret-width * .85;
+        content: "";
+        @include caret-left;
       }
     }
 
diff --git a/assets/stylesheets/bootstrap/mixins/_forms.scss b/assets/stylesheets/bootstrap/mixins/_forms.scss
index 564222a..d25df18 100644
--- a/assets/stylesheets/bootstrap/mixins/_forms.scss
+++ b/assets/stylesheets/bootstrap/mixins/_forms.scss
@@ -15,12 +15,12 @@
     color: $input-focus-color;
     background-color: $input-focus-bg;
     border-color: $input-focus-border-color;
-    outline: none;
+    outline: 0;
     // Avoid using mixin so we can pass custom focus shadow properly
     @if $enable-shadows {
-      box-shadow: $input-box-shadow, $input-btn-focus-box-shadow;
+      box-shadow: $input-box-shadow, $input-focus-box-shadow;
     } @else {
-      box-shadow: $input-btn-focus-box-shadow;
+      box-shadow: $input-focus-box-shadow;
     }
   }
 }
@@ -30,8 +30,9 @@
 
   .#{$state}-feedback {
     display: none;
-    margin-top: .25rem;
-    font-size: .875rem;
+    width: 100%;
+    margin-top: $form-feedback-margin-top;
+    font-size: $form-feedback-font-size;
     color: $color;
   }
 
@@ -57,7 +58,8 @@
       border-color: $color;
 
       &:focus {
-        box-shadow: 0 0 0 $input-btn-focus-width rgba($color, .25);
+        border-color: $color;
+        box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
       }
 
       ~ .#{$state}-feedback,
@@ -67,30 +69,40 @@
     }
   }
 
-
-  // TODO: redo check markup lol crap
   .form-check-input {
     .was-validated &:#{$state},
     &.is-#{$state} {
-      + .form-check-label {
+      ~ .form-check-label {
         color: $color;
       }
     }
   }
 
-  // custom radios and checks
   .custom-control-input {
     .was-validated &:#{$state},
     &.is-#{$state} {
-      ~ .custom-control-indicator {
-        background-color: rgba($color, .4);
-      }
-      ~ .custom-control-description {
+      ~ .custom-control-label {
         color: $color;
+
+        &::before {
+          background-color: lighten($color, 25%);
+        }
+      }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
       }
+
+      &:checked {
+        ~ .custom-control-label::before {
+          @include gradient-bg(lighten($color, 10%));
+        }
+      }
+
       &:focus {
-        ~ .custom-control-indicator {
-          box-shadow: 0 0 0 1px $body-bg, 0 0 0 $input-btn-focus-width rgba($color, .25);
+        ~ .custom-control-label::before {
+          box-shadow: 0 0 0 1px $body-bg, 0 0 0 $input-focus-width rgba($color, .25);
         }
       }
     }
@@ -100,14 +112,20 @@
   .custom-file-input {
     .was-validated &:#{$state},
     &.is-#{$state} {
-      ~ .custom-file-control {
+      ~ .custom-file-label {
         border-color: $color;
 
         &::before { border-color: inherit; }
       }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+
       &:focus {
-        ~ .custom-file-control {
-          box-shadow: 0 0 0 $input-btn-focus-width rgba($color, .25);
+        ~ .custom-file-label {
+          box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
         }
       }
     }
diff --git a/assets/stylesheets/bootstrap/mixins/_text-hide.scss b/assets/stylesheets/bootstrap/mixins/_text-hide.scss
index 52a38a9..aa551fd 100644
--- a/assets/stylesheets/bootstrap/mixins/_text-hide.scss
+++ b/assets/stylesheets/bootstrap/mixins/_text-hide.scss
@@ -1,5 +1,6 @@
 // CSS image replacement
 @mixin text-hide() {
+  // stylelint-disable-next-line font-family-no-missing-generic-family-keyword
   font: 0/0 a;
   color: transparent;
   text-shadow: none;
diff --git a/assets/stylesheets/bootstrap/utilities/_borders.scss b/assets/stylesheets/bootstrap/utilities/_borders.scss
index ba02f04..b8832ef 100644
--- a/assets/stylesheets/bootstrap/utilities/_borders.scss
+++ b/assets/stylesheets/bootstrap/utilities/_borders.scss
@@ -4,7 +4,12 @@
 // Border
 //
 
-.border          { border: $border-width solid $border-color !important; }
+.border         { border: $border-width solid $border-color !important; }
+.border-top     { border-top: $border-width solid $border-color !important; }
+.border-right   { border-right: $border-width solid $border-color !important; }
+.border-bottom  { border-bottom: $border-width solid $border-color !important; }
+.border-left    { border-left: $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; }
-- 
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