rake update[v4-dev]

18 files changed, 402 insertions, 425 deletions

diff --git a/assets/stylesheets/bootstrap/_button-group.scss b/assets/stylesheets/bootstrap/_button-group.scss
index ff6c33f..60e9f7a 100644
--- a/assets/stylesheets/bootstrap/_button-group.scss
+++ b/assets/stylesheets/bootstrap/_button-group.scss
@@ -104,16 +104,26 @@
 // Split button dropdowns
 //
 
-// Give the line between buttons some depth
-.btn-group > .btn + .dropdown-toggle {
-  padding-right: $split-btn-dropdown-toggle-padding-x;
-  padding-left: $split-btn-dropdown-toggle-padding-x;
+.btn + .dropdown-toggle-split {
+  padding-right: $btn-padding-x * .75;
+  padding-left: $btn-padding-x * .75;
+
+  &::after {
+    margin-left: 0;
+  }
 }
-.btn-group > .btn-lg + .dropdown-toggle {
-  padding-right: $split-btn-lg-dropdown-toggle-padding-x;
-  padding-left: $split-btn-lg-dropdown-toggle-padding-x;
+
+.btn-sm + .dropdown-toggle-split {
+  padding-right: $btn-padding-x-sm * .75;
+  padding-left: $btn-padding-x-sm * .75;
 }
 
+.btn-lg + .dropdown-toggle-split {
+  padding-right: $btn-padding-x-lg * .75;
+  padding-left: $btn-padding-x-lg * .75;
+}
+
+
 // The clickable button for toggling the menu
 // Remove the gradient and set the same inset shadow as the :active state
 .btn-group.open .dropdown-toggle {
diff --git a/assets/stylesheets/bootstrap/_card.scss b/assets/stylesheets/bootstrap/_card.scss
index 856d6c6..a419d4d 100644
--- a/assets/stylesheets/bootstrap/_card.scss
+++ b/assets/stylesheets/bootstrap/_card.scss
@@ -9,8 +9,7 @@
   background-color: $card-bg;
   // border: $card-border-width solid $card-border-color;
   @include border-radius($card-border-radius);
-  // Doesn't use mixin so that cards always have a "border"
-  box-shadow: inset 0 0 0 $card-border-width $card-border-color;
+  border: $card-border-width solid $card-border-color;
 }
 
 .card-block {
@@ -49,20 +48,16 @@
   }
 }
 
-@if $enable-rounded {
-  .card {
-    > .list-group:first-child {
-      .list-group-item:first-child {
-        border-top-left-radius: $card-border-radius;
-        border-top-right-radius: $card-border-radius;
-      }
+.card {
+  > .list-group:first-child {
+    .list-group-item:first-child {
+      @include border-top-radius($card-border-radius);
     }
+  }
 
-    > .list-group:last-child {
-      .list-group-item:last-child {
-        border-bottom-right-radius: $card-border-radius;
-        border-bottom-left-radius: $card-border-radius;
-      }
+  > .list-group:last-child {
+    .list-group-item:last-child {
+      @include border-bottom-radius($card-border-radius);
     }
   }
 }
@@ -76,9 +71,7 @@
   @include clearfix;
   padding: $card-spacer-y $card-spacer-x;
   background-color: $card-cap-bg;
-  // border-bottom: $card-border-width solid $card-border-color;
-  // Doesn't use mixin so that cards always have a "border"
-  box-shadow: inset 0 0 0 $card-border-width $card-border-color;
+  border-bottom: $card-border-width solid $card-border-color;
 
   &:first-child {
     @include border-radius($card-border-radius-inner $card-border-radius-inner 0 0);
@@ -89,9 +82,7 @@
   @include clearfix;
   padding: $card-spacer-y $card-spacer-x;
   background-color: $card-cap-bg;
-  // border-top: $card-border-width solid $card-border-color;
-  // Doesn't use mixin so that cards always have a "border"
-  box-shadow: inset 0 0 0 $card-border-width $card-border-color;
+  border-top: $card-border-width solid $card-border-color;
 
   &:last-child {
     @include border-radius(0 0 $card-border-radius-inner $card-border-radius-inner);
@@ -108,10 +99,6 @@
   margin-bottom: -$card-spacer-y;
   margin-left: -($card-spacer-x / 2);
   border-bottom: 0;
-
-  .nav-item {
-    margin-bottom: 0;
-  }
 }
 
 .card-header-pills {
@@ -189,23 +176,28 @@
   right: 0;
   bottom: 0;
   left: 0;
-  padding: 1.25rem;
+  padding: $card-img-overlay-padding;
 }
 
 
 
 // Card image caps
 .card-img-top {
-  @include border-radius($card-border-radius-inner $card-border-radius-inner 0 0);
+  @include border-top-radius($card-border-radius-inner);
 }
 .card-img-bottom {
-  @include border-radius(0 0 $card-border-radius-inner $card-border-radius-inner);
+  @include border-bottom-radius($card-border-radius-inner);
 }
 
 
-//
 // Card set
 //
+// Heads up! We do some funky style resetting here for margins across our two
+// variations (one flex, one table). Individual cards have margin-bottom by
+// default, but they're ignored due to table styles. For a consistent design,
+// we've done the same to the flex variation.
+//
+// Those changes are noted by `// Margin balancing`.
 
 @if $enable-flex {
   @include media-breakpoint-up(sm) {
@@ -213,11 +205,13 @@
       display: flex;
       flex-flow: row wrap;
       margin-right: -$card-deck-margin;
+      margin-bottom: $card-spacer-y; // Margin balancing
       margin-left: -$card-deck-margin;
 
       .card {
         flex: 1 0 0;
         margin-right: $card-deck-margin;
+        margin-bottom: 0; // Margin balancing
         margin-left: $card-deck-margin;
       }
     }
@@ -227,12 +221,14 @@
     $space-between-cards: (2 * $card-deck-margin);
     .card-deck {
       display: table;
+      width: 100%;
+      margin-bottom: $card-spacer-y; // Margin balancing
       table-layout: fixed;
       border-spacing: $space-between-cards 0;
 
       .card {
         display: table-cell;
-        width: 1%;
+        margin-bottom: 0; // Margin balancing
         vertical-align: top;
       }
     }
diff --git a/assets/stylesheets/bootstrap/_carousel.scss b/assets/stylesheets/bootstrap/_carousel.scss
index 2ff886a..9386983 100644
--- a/assets/stylesheets/bootstrap/_carousel.scss
+++ b/assets/stylesheets/bootstrap/_carousel.scss
@@ -125,19 +125,19 @@
     top: 50%;
     z-index: 5;
     display: inline-block;
-    width: 20px;
-    height: 20px;
-    margin-top: -10px;
+    width: $carousel-icon-width;
+    height: $carousel-icon-width;
+    margin-top: -($carousel-icon-width / 2);
     font-family: serif;
     line-height: 1;
   }
   .icon-prev {
     left: 50%;
-    margin-left: -10px;
+    margin-left: -($carousel-icon-width / 2);
   }
   .icon-next {
     right: 50%;
-    margin-right: -10px;
+    margin-right: -($carousel-icon-width / 2);
   }
 
   .icon-prev {
diff --git a/assets/stylesheets/bootstrap/_custom-forms.scss b/assets/stylesheets/bootstrap/_custom-forms.scss
index 371945c..a5f0bdf 100644
--- a/assets/stylesheets/bootstrap/_custom-forms.scss
+++ b/assets/stylesheets/bootstrap/_custom-forms.scss
@@ -159,6 +159,22 @@
     border-color: $custom-select-focus-border-color;
     outline: none;
     @include box-shadow($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
+      // 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.
+      color: $input-color;
+      background-color: $input-bg;
+    }
+  }
+
+  &:disabled {
+    color: $custom-select-disabled-color;
+    cursor: $cursor-disabled;
+    background-color: $custom-select-disabled-bg;
   }
 
   // Hides the default caret in IE11
diff --git a/assets/stylesheets/bootstrap/_dropdown.scss b/assets/stylesheets/bootstrap/_dropdown.scss
index 47fc204..e696d28 100644
--- a/assets/stylesheets/bootstrap/_dropdown.scss
+++ b/assets/stylesheets/bootstrap/_dropdown.scss
@@ -10,8 +10,7 @@
     display: inline-block;
     width: 0;
     height: 0;
-    margin-right: .25rem;
-    margin-left: .25rem;
+    margin-left: $caret-width;
     vertical-align: middle;
     content: "";
     border-top: $caret-width solid;
diff --git a/assets/stylesheets/bootstrap/_forms.scss b/assets/stylesheets/bootstrap/_forms.scss
index 9a031c3..263a8bc 100644
--- a/assets/stylesheets/bootstrap/_forms.scss
+++ b/assets/stylesheets/bootstrap/_forms.scss
@@ -60,6 +60,16 @@ select.form-control {
   &:not([size]):not([multiple]) {
     height: $input-height;
   }
+
+  &:focus::-ms-value {
+    // Suppress the nested 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, as it looks bad and cannot be made to
+    // match the appearance of the native widget.
+    // See https://github.com/twbs/bootstrap/issues/19398.
+    color: $input-color;
+    background-color: $input-bg;
+  }
 }
 
 // Make file inputs better match text inputs by forcing them to new lines.
@@ -75,56 +85,39 @@ select.form-control {
 
 // For use with horizontal and inline forms, when you need the label text to
 // align with the form controls.
-.form-control-label {
-  padding: $input-padding-y $input-padding-x;
+.col-form-label {
+  padding-top: $input-padding-y;
+  padding-bottom: $input-padding-y;
   margin-bottom: 0; // Override the `<label>` default
 }
 
+.col-form-label-lg {
+  padding-top: $input-padding-y-lg;
+  padding-bottom: $input-padding-y-lg;
+  font-size: $font-size-lg;
+}
+
+.col-form-label-sm {
+  padding-top: $input-padding-y-sm;
+  padding-bottom: $input-padding-y-sm;
+  font-size: $font-size-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.
-.form-control-legend {
-  padding: $input-padding-y $input-padding-x;
+.col-form-legend {
+  padding-top: $input-padding-y;
+  padding-bottom: $input-padding-y;
   margin-bottom: 0;
   font-size: $font-size-base;
 }
 
 
-// Todo: clear this up
-
-// Special styles for iOS temporal inputs
-//
-// In Mobile Safari, setting `display: block` on temporal inputs causes the
-// text within the input to become vertically misaligned. As a workaround, we
-// set a pixel line-height that matches the given height of the input, but only
-// for Safari. See https://bugs.webkit.org/show_bug.cgi?id=139848
-//
-// Note that as of 8.3, iOS doesn't support `week`.
-
-_::-webkit-full-page-media, // Hack to make this CSS be Safari-only; see http://browserbu.gs/css-hacks/webkit-full-page-media/
-input[type="date"],
-input[type="time"],
-input[type="datetime-local"],
-input[type="month"] {
-  &.form-control {
-    line-height: $input-height;
-  }
-
-  &.input-sm,
-  .input-group-sm &.form-control {
-    line-height: $input-height-sm;
-  }
-
-  &.input-lg,
-  .input-group-lg &.form-control {
-    line-height: $input-height-lg;
-  }
-}
-
-
 // Static form control text
 //
 // Apply class to an element to make any string of text align with labels in a
@@ -160,12 +153,24 @@ input[type="month"] {
   @include border-radius($input-border-radius-sm);
 }
 
+select.form-control-sm {
+  &:not([size]):not([multiple]) {
+    height: $input-height-sm;
+  }
+}
+
 .form-control-lg {
   padding: $input-padding-y-lg $input-padding-x-lg;
   font-size: $font-size-lg;
   @include border-radius($input-border-radius-lg);
 }
 
+select.form-control-lg {
+  &:not([size]):not([multiple]) {
+    height: $input-height-lg;
+  }
+}
+
 
 // Form groups
 //
@@ -176,94 +181,77 @@ input[type="month"] {
   margin-bottom: $form-group-margin-bottom;
 }
 
+.form-text {
+  display: block;
+  margin-top: ($spacer * .25);
+}
+
 
 // Checkboxes and radios
 //
 // Indent the labels to position radios/checkboxes as hanging controls.
 
-.radio,
-.checkbox {
+.form-check {
   position: relative;
   display: block;
-  // margin-top:    ($spacer * .75);
   margin-bottom: ($spacer * .75);
 
-  label {
-    padding-left: 1.25rem;
-    margin-bottom: 0;
-    cursor: pointer;
+  // Move up sibling radios or checkboxes for tighter spacing
+  + .form-check {
+    margin-top: -.25rem;
+  }
 
-    // When there's no labels, don't position the input.
-    input:only-child {
-      position: static;
+  &.disabled {
+    .form-check-label {
+      color: $text-muted;
+      cursor: $cursor-disabled;
     }
   }
 }
-.radio input[type="radio"],
-.radio-inline input[type="radio"],
-.checkbox input[type="checkbox"],
-.checkbox-inline input[type="checkbox"] {
+
+.form-check-label {
+  padding-left: 1.25rem;
+  margin-bottom: 0; // Override default `<label>` bottom margin
+  cursor: pointer;
+}
+
+.form-check-input {
   position: absolute;
   margin-top: .25rem;
-  // margin-top: 4px \9;
   margin-left: -1.25rem;
-}
 
-.radio + .radio,
-.checkbox + .checkbox {
-  // Move up sibling radios or checkboxes for tighter spacing
-  margin-top: -.25rem;
+  &:only-child {
+    position: static;
+  }
 }
 
 // Radios and checkboxes on same line
-.radio-inline,
-.checkbox-inline {
+.form-check-inline {
   position: relative;
   display: inline-block;
   padding-left: 1.25rem;
-  margin-bottom: 0;
+  margin-bottom: 0; // Override default `<label>` bottom margin
   vertical-align: middle;
   cursor: pointer;
-}
-.radio-inline + .radio-inline,
-.checkbox-inline + .checkbox-inline {
-  margin-top: 0;
-  margin-left: .75rem;
-}
 
-// Apply same disabled cursor tweak as for inputs
-// Some special care is needed because <label>s don't inherit their parent's `cursor`.
-//
-// Note: Neither radios nor checkboxes can be readonly.
-input[type="radio"],
-input[type="checkbox"] {
-  &:disabled,
-  &.disabled {
-    cursor: $cursor-disabled;
+  + .form-check-inline {
+    margin-left: .75rem;
   }
-}
-// These classes are used directly on <label>s
-.radio-inline,
-.checkbox-inline {
+
   &.disabled {
     cursor: $cursor-disabled;
   }
 }
-// These classes are used on elements with <label> descendants
-.radio,
-.checkbox {
-  &.disabled {
-    label {
-      cursor: $cursor-disabled;
-    }
-  }
-}
 
 
 // Form control feedback states
 //
 // Apply contextual and semantic states to individual form controls.
 
+.form-control-feedback {
+  margin-top: ($spacer * .25);
+}
+
 .form-control-success,
 .form-control-warning,
 .form-control-danger {
@@ -299,84 +287,6 @@ input[type="checkbox"] {
 }
 
 
-
-
-// .form-control-success {
-//   background-image: $form-icon-success;
-//   border-color: $brand-success;
-// }
-//
-// .form-control-warning {
-//   background-image: $form-icon-warning;
-//   border-color: $brand-warning;
-// }
-//
-// .form-control-error {
-//   background-image: $form-icon-danger;
-//   border-color: $brand-danger;
-// }
-
-
-// .has-feedback {
-//   // Enable absolute positioning
-//   position: relative;
-//
-//   // Ensure icons don't overlap text
-//   .form-control {
-//     padding-right: ($input-height * 1.25);
-//   }
-// }
-// // Feedback icon
-// .form-control-feedback {
-//   position: absolute;
-//   top: 0;
-//   right: 0;
-//   z-index: 2; // Ensure icon is above input groups
-//   display: block;
-//   width: $input-height;
-//   height: $input-height;
-//   line-height: $input-height;
-//   text-align: center;
-//   pointer-events: none;
-// }
-// .input-lg + .form-control-feedback,
-// .input-group-lg + .form-control-feedback {
-//   width: $input-height-lg;
-//   height: $input-height-lg;
-//   line-height: $input-height-lg;
-// }
-// .input-sm + .form-control-feedback,
-// .input-group-sm + .form-control-feedback {
-//   width: $input-height-sm;
-//   height: $input-height-sm;
-//   line-height: $input-height-sm;
-// }
-//
-// // Form validation states
-// .has-success {
-//   @include form-control-validation($state-success-text, $state-success-text, $state-success-bg);
-// }
-// .has-warning {
-//   @include form-control-validation($state-warning-text, $state-warning-text, $state-warning-bg);
-// }
-// .has-danger {
-//   @include form-control-validation($state-danger-text, $state-danger-text, $state-danger-bg);
-// }
-//
-// // Reposition feedback icon if input has visible label above
-// .has-feedback label {
-//
-//   ~ .form-control-feedback {
-//     // TODO: redo this since we nuked the `$line-height-computed`
-//     top: 0; // Height of the `label` and its margin
-//   }
-//
-//   &.sr-only ~ .form-control-feedback {
-//     top: 0;
-//   }
-// }
-
-
 // Inline forms
 //
 // Make forms appear inline(-block) by adding the `.form-inline` class. Inline
@@ -432,19 +342,16 @@ input[type="checkbox"] {
 
     // Remove default margin on radios/checkboxes that were used for stacking, and
     // then undo the floating of radios and checkboxes to match.
-    .radio,
-    .checkbox {
+    .form-check {
       display: inline-block;
       margin-top: 0;
       margin-bottom: 0;
       vertical-align: middle;
-
-      label {
-        padding-left: 0;
-      }
     }
-    .radio input[type="radio"],
-    .checkbox input[type="checkbox"] {
+    .form-check-label {
+      padding-left: 0;
+    }
+    .form-check-input {
       position: relative;
       margin-left: 0;
     }
diff --git a/assets/stylesheets/bootstrap/_images.scss b/assets/stylesheets/bootstrap/_images.scss
index d17006d..9894269 100644
--- a/assets/stylesheets/bootstrap/_images.scss
+++ b/assets/stylesheets/bootstrap/_images.scss
@@ -19,7 +19,7 @@
   padding: $thumbnail-padding;
   background-color: $thumbnail-bg;
   border: $thumbnail-border-width solid $thumbnail-border-color;
-  border-radius: $thumbnail-border-radius;
+  @include border-radius($thumbnail-border-radius);
   transition: all .2s ease-in-out;
   @include box-shadow($thumbnail-box-shadow);
 
diff --git a/assets/stylesheets/bootstrap/_nav.scss b/assets/stylesheets/bootstrap/_nav.scss
index 6bb09fd..640956c 100644
--- a/assets/stylesheets/bootstrap/_nav.scss
+++ b/assets/stylesheets/bootstrap/_nav.scss
@@ -65,7 +65,7 @@
     display: block;
     padding: $nav-link-padding;
     border: $nav-tabs-border-width solid transparent;
-    @include border-radius($border-radius $border-radius 0 0);
+    @include border-top-radius($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;
diff --git a/assets/stylesheets/bootstrap/_navbar.scss b/assets/stylesheets/bootstrap/_navbar.scss
index 85a3697..6c4e9ef 100644
--- a/assets/stylesheets/bootstrap/_navbar.scss
+++ b/assets/stylesheets/bootstrap/_navbar.scss
@@ -86,7 +86,7 @@
 
 .navbar-divider {
   float: left;
-  width: 1px;
+  width: $border-width;
   padding-top: .425rem;
   padding-bottom: .425rem;
   margin-right: $navbar-padding-x;
diff --git a/assets/stylesheets/bootstrap/_normalize.scss b/assets/stylesheets/bootstrap/_normalize.scss
index 93dd452..8a74836 100644
--- a/assets/stylesheets/bootstrap/_normalize.scss
+++ b/assets/stylesheets/bootstrap/_normalize.scss
@@ -1,9 +1,8 @@
-/*! normalize.css commit fe56763 | MIT License | github.com/necolas/normalize.css */
+/*! normalize.css v4.0.0 | MIT License | github.com/necolas/normalize.css */
 
 //
-// 1. Set default font family to sans-serif.
-// 2. Prevent iOS and IE text size adjust after device orientation change,
-//    without disabling user zoom.
+// 1. Change the default font family in all browsers (opinionated).
+// 2. Prevent adjustments of font size after orientation changes in IE and iOS.
 //
 
 html {
@@ -13,7 +12,7 @@ html {
 }
 
 //
-// Remove default margin.
+// Remove the margin in all browsers (opinionated).
 //
 
 body {
@@ -24,43 +23,39 @@ body {
 // ==========================================================================
 
 //
-// Correct `block` display not defined for any HTML5 element in IE 8/9.
-// Correct `block` display not defined for `details` or `summary` in IE 10/11
-// and Firefox.
-// Correct `block` display not defined for `main` in IE 11.
+// Add the correct display in IE 9-.
+// 1. Add the correct display in Edge, IE, and Firefox.
+// 2. Add the correct display in IE.
 //
 
 article,
 aside,
-details,
+details, // 1
 figcaption,
 figure,
 footer,
 header,
-main,
+main, // 2
 menu,
 nav,
 section,
-summary {
+summary { // 1
   display: block;
 }
 
 //
-// 1. Correct `inline-block` display not defined in IE 8/9.
-// 2. Normalize vertical alignment of `progress` in Chrome, Firefox, and Opera.
+// Add the correct display in IE 9-.
 //
 
 audio,
 canvas,
 progress,
 video {
-  display: inline-block; // 1
-  vertical-align: baseline; // 2
+  display: inline-block;
 }
 
 //
-// Prevent modern browsers from displaying `audio` without controls.
-// Remove excess height in iOS 5 devices.
+// Add the correct display in iOS 4-7.
 //
 
 audio:not([controls]) {
@@ -69,12 +64,20 @@ audio:not([controls]) {
 }
 
 //
-// Address `[hidden]` styling not present in IE 8/9/10.
-// Hide the `template` element in IE 8/9/10/11, Safari, and Firefox < 22.
+// Add the correct vertical alignment in Chrome, Firefox, and Opera.
 //
 
-[hidden],
-template {
+progress {
+  vertical-align: baseline;
+}
+
+//
+// Add the correct display in IE 10-.
+// 1. Add the correct display in IE.
+//
+
+template, // 2
+[hidden] {
   display: none;
 }
 
@@ -82,7 +85,7 @@ template {
 // ==========================================================================
 
 //
-// Remove the gray background color from active links in IE 10.
+// Remove the gray background on active links in IE 10.
 //
 
 a {
@@ -90,41 +93,49 @@ a {
 }
 
 //
-// Improve readability of focused elements when they are also in an
-// active/hover state.
+// Remove the outline on focused links when they are also active or hovered
+// in all browsers (opinionated).
 //
 
-a {
-  &:active {
-    outline: 0;
-  }
-  &:hover {
-    outline: 0;
-  }
+a:active,
+a:hover {
+  outline-width: 0;
 }
 
 // Text-level semantics
 // ==========================================================================
 
 //
-// Address styling not present in IE 8/9/10/11, Safari, and Chrome.
+// 1. Remove the bottom border in Firefox 39-.
+// 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
 //
 
 abbr[title] {
-  border-bottom: 1px dotted;
+  border-bottom: none; // 1
+  text-decoration: underline; // 2
+  text-decoration: underline dotted; // 2
 }
 
 //
-// Address style set to `bolder` in Firefox 4+, Safari, and Chrome.
+// Prevent the duplicate application of `bolder` by the next rule in Safari 6.
 //
 
 b,
 strong {
-  font-weight: bold;
+  font-weight: inherit;
+}
+
+//
+// Add the correct font weight in Chrome, Edge, and Safari.
+//
+
+b,
+strong {
+  font-weight: bolder;
 }
 
 //
-// Address styling not present in Safari and Chrome.
+// Add the correct font style in Android 4.3-.
 //
 
 dfn {
@@ -132,8 +143,8 @@ dfn {
 }
 
 //
-// Address variable `h1` font-size and margin within `section` and `article`
-// contexts in Firefox 4+, Safari, and Chrome.
+// Correct the font size and margin on `h1` elements within `section` and
+// `article` contexts in Chrome, Firefox, and Safari.
 //
 
 h1 {
@@ -142,16 +153,16 @@ h1 {
 }
 
 //
-// Address styling not present in IE 8/9.
+// Add the correct background and color in IE 9-.
 //
 
 mark {
-  background: #ff0;
+  background-color: #ff0;
   color: #000;
 }
 
 //
-// Address inconsistent and variable font size in all browsers.
+// Add the correct font size in all browsers.
 //
 
 small {
@@ -159,7 +170,8 @@ small {
 }
 
 //
-// Prevent `sub` and `sup` affecting `line-height` in all browsers.
+// Prevent `sub` and `sup` elements from affecting the line height in
+// all browsers.
 //
 
 sub,
@@ -170,27 +182,27 @@ sup {
   vertical-align: baseline;
 }
 
-sup {
-  top: -0.5em;
-}
-
 sub {
   bottom: -0.25em;
 }
 
+sup {
+  top: -0.5em;
+}
+
 // Embedded content
 // ==========================================================================
 
 //
-// Remove border when inside `a` element in IE 8/9/10.
+// Remove the border on images inside links in IE 10-.
 //
 
 img {
-  border: 0;
+  border-style: none;
 }
 
 //
-// Correct overflow not hidden in IE 9/10/11.
+// Hide the overflow in IE.
 //
 
 svg:not(:root) {
@@ -201,177 +213,146 @@ svg:not(:root) {
 // ==========================================================================
 
 //
-// Address margin not present in IE 8/9 and Safari.
+// 1. Correct the inheritance and scaling of font size in all browsers.
+// 2. Correct the odd `em` font sizing in all browsers.
 //
 
-figure {
-  margin: 1em 40px;
-}
-
-//
-// Address differences between Firefox and other browsers.
-//
-
-hr {
-  box-sizing: content-box;
-  height: 0;
+code,
+kbd,
+pre,
+samp {
+  font-family: monospace, monospace; // 1
+  font-size: 1em; // 2
 }
 
 //
-// Contain overflow in all browsers.
+// Add the correct margin in IE 8.
 //
 
-pre {
-  overflow: auto;
+figure {
+  margin: 1em 40px;
 }
 
 //
-// Address odd `em`-unit font size rendering in all browsers.
+// 1. Add the correct box sizing in Firefox.
+// 2. Show the overflow in Edge and IE.
 //
 
-code,
-kbd,
-pre,
-samp {
-  font-family: monospace, monospace;
-  font-size: 1em;
+hr {
+  box-sizing: content-box; // 1
+  height: 0; // 1
+  overflow: visible; // 2
 }
 
 // Forms
 // ==========================================================================
 
 //
-// Known limitation: by default, Chrome and Safari on OS X allow very limited
-// styling of `select`, unless a `border` property is set.
-//
-
-//
-// 1. Correct color not being inherited.
-//    Known issue: affects color of disabled elements.
-// 2. Correct font properties not being inherited.
-// 3. Address margins set differently in Firefox 4+, Safari, and Chrome.
+// Change font properties to `inherit` in all browsers (opinionated).
 //
 
 button,
 input,
-optgroup,
 select,
 textarea {
-  color: inherit; // 1
-  font: inherit; // 2
-  margin: 0; // 3
+  font: inherit;
 }
 
 //
-// Address `overflow` set to `hidden` in IE 8/9/10/11.
+// Restore the font weight unset by the previous rule.
 //
 
-button {
-  overflow: visible;
+optgroup {
+  font-weight: bold;
 }
 
 //
-// Address inconsistent `text-transform` inheritance for `button` and `select`.
-// All other form control elements do not inherit `text-transform` values.
-// Correct `button` style inheritance in Firefox, IE 8/9/10/11, and Opera.
-// Correct `select` style inheritance in Firefox.
+// Show the overflow in IE.
+// 1. Show the overflow in Edge.
+// 2. Show the overflow in Edge, Firefox, and IE.
 //
 
 button,
-select {
-  text-transform: none;
+input, // 1
+select { // 2
+  overflow: visible;
 }
 
 //
-// 1. Avoid the WebKit bug in Android 4.0.* where (2) destroys native `audio`
-//    and `video` controls.
-// 2. Correct inability to style clickable `input` types in iOS.
-// 3. Improve usability and consistency of cursor style between image-type
-//    `input` and others.
+// Remove the margin in Safari.
+// 1. Remove the margin in Firefox and Safari.
 //
 
 button,
-html input[type="button"], // 1
-input[type="reset"],
-input[type="submit"] {
-  -webkit-appearance: button; // 2
-  cursor: pointer; // 3
-}
-
-//
-// Re-set default cursor for disabled elements.
-//
-
-button[disabled],
-html input[disabled] {
-  cursor: default;
+input,
+select,
+textarea { // 1
+  margin: 0;
 }
 
 //
-// Remove inner padding and border in Firefox 4+.
+// Remove the inheritence of text transform in Edge, Firefox, and IE.
+// 1. Remove the inheritence of text transform in Firefox.
 //
 
-button::-moz-focus-inner,
-input::-moz-focus-inner {
-  border: 0;
-  padding: 0;
+button,
+select { // 1
+  text-transform: none;
 }
 
 //
-// Address Firefox 4+ setting `line-height` on `input` using `!important` in
-// the UA stylesheet.
+// Change the cursor in all browsers (opinionated).
 //
 
-input {
-  line-height: normal;
+button,
+[type="button"],
+[type="reset"],
+[type="submit"] {
+  cursor: pointer;
 }
 
 //
-// It's recommended that you don't attempt to style these elements.
-// Firefox's implementation doesn't respect box-sizing, padding, or width.
-//
-// 1. Address box sizing set to `content-box` in IE 8/9/10.
-// 2. Remove excess padding in IE 8/9/10.
+// Restore the default cursor to disabled elements unset by the previous rule.
 //
 
-input[type="checkbox"],
-input[type="radio"] {
-  box-sizing: border-box; // 1
-  padding: 0; // 2
+[disabled] {
+  cursor: default;
 }
 
 //
-// Fix the cursor style for Chrome's increment/decrement buttons. For certain
-// `font-size` values of the `input`, it causes the cursor style of the
-// decrement button to change from `default` to `text`.
+// 1. Prevent a WebKit bug where (2) destroys native `audio` and `video`
+//    controls in Android 4.
+// 2. Correct the inability to style clickable types in iOS.
 //
 
-input[type="number"]::-webkit-inner-spin-button,
-input[type="number"]::-webkit-outer-spin-button {
-  height: auto;
+button,
+html [type="button"], // 1
+[type="reset"],
+[type="submit"] {
+  -webkit-appearance: button; // 2
 }
 
 //
-// Address `appearance` set to `searchfield` in Safari and Chrome.
+// Remove the inner border and padding in Firefox.
 //
 
-input[type="search"] {
-  -webkit-appearance: textfield;
+button::-moz-focus-inner,
+input::-moz-focus-inner {
+  border: 0;
+  padding: 0;
 }
 
 //
-// Remove inner padding and search cancel button in Safari and Chrome on OS X.
-// Safari (but not Chrome) clips the cancel button when the search input has
-// padding (and `textfield` appearance).
+// Restore the focus styles unset by the previous rule.
 //
 
-input[type="search"]::-webkit-search-cancel-button,
-input[type="search"]::-webkit-search-decoration {
-  -webkit-appearance: none;
+button:-moz-focusring,
+input:-moz-focusring {
+  outline: 1px dotted ButtonText;
 }
 
 //
-// Define consistent border, margin, and padding.
+// Change the border, margin, and padding in all browsers (opinionated).
 //
 
 fieldset {
@@ -381,17 +362,23 @@ fieldset {
 }
 
 //
-// 1. Correct `color` not being inherited in IE 8/9/10/11.
-// 2. Remove padding so people aren't caught out if they zero out fieldsets.
+// 1. Correct the text wrapping in Edge and IE.
+// 2. Correct the color inheritance from `fieldset` elements in IE.
+// 3. Remove the padding so developers are not caught out when they zero out
+//    `fieldset` elements in all browsers.
 //
 
 legend {
-  border: 0; // 1
-  padding: 0; // 2
+  box-sizing: border-box; // 1
+  color: inherit; // 2
+  display: table; // 1
+  max-width: 100%; // 1
+  padding: 0; // 3
+  white-space: normal; // 1
 }
 
 //
-// Remove default vertical scrollbar in IE 8/9/10/11.
+// Remove the default vertical scrollbar in IE.
 //
 
 textarea {
@@ -399,27 +386,39 @@ textarea {
 }
 
 //
-// Don't inherit the `font-weight` (applied by a rule above).
-// NOTE: the default cannot safely be changed in Chrome and Safari on OS X.
+// 1. Add the correct box sizing in IE 10-.
+// 2. Remove the padding in IE 10-.
 //
 
-optgroup {
-  font-weight: bold;
+[type="checkbox"],
+[type="radio"] {
+  box-sizing: border-box; // 1
+  padding: 0; // 2
 }
 
-// Tables
-// ==========================================================================
+//
+// Correct the cursor style of increment and decrement buttons in Chrome.
+//
+
+[type="number"]::-webkit-inner-spin-button,
+[type="number"]::-webkit-outer-spin-button {
+  height: auto;
+}
 
 //
-// Remove most spacing between table cells.
+// Correct the odd appearance of search inputs in Chrome and Safari.
 //
 
-table {
-  border-collapse: collapse;
-  border-spacing: 0;
+[type="search"] {
+  -webkit-appearance: textfield;
 }
 
-td,
-th {
-  padding: 0;
+//
+// Remove the inner padding and cancel buttons in Chrome on OS X and
+// Safari on OS X.
+//
+
+[type="search"]::-webkit-search-cancel-button,
+[type="search"]::-webkit-search-decoration {
+  -webkit-appearance: none;
 }
diff --git a/assets/stylesheets/bootstrap/_popover.scss b/assets/stylesheets/bootstrap/_popover.scss
index 9ea8c14..6e6fe3c 100644
--- a/assets/stylesheets/bootstrap/_popover.scss
+++ b/assets/stylesheets/bootstrap/_popover.scss
@@ -5,7 +5,7 @@
   z-index: $zindex-popover;
   display: block;
   max-width: $popover-max-width;
-  padding: 1px;
+  padding: $popover-inner-padding;
   // 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();
@@ -112,6 +112,10 @@
   border-bottom: $popover-border-width solid darken($popover-title-bg, 5%);
   $offset-border-width: ($border-width / $font-size-root);
   @include border-radius(($border-radius-lg - $offset-border-width) ($border-radius-lg - $offset-border-width) 0 0);
+
+  &:empty {
+    display: none;
+  }
 }
 
 .popover-content {
diff --git a/assets/stylesheets/bootstrap/_reboot.scss b/assets/stylesheets/bootstrap/_reboot.scss
index 4906cb4..02c579d 100644
--- a/assets/stylesheets/bootstrap/_reboot.scss
+++ b/assets/stylesheets/bootstrap/_reboot.scss
@@ -171,12 +171,13 @@ a {
   }
 }
 
-// And undo these styles for placeholder links/named anchors (without href).
+// And undo these styles for placeholder links/named anchors (without href)
+// which have not been made explicitly keyboard-focusable (without tabindex).
 // It would be more straightforward to just use a[href] in previous block, but that
 // causes specificity issues in many other styles that are too complex to fix.
 // See https://github.com/twbs/bootstrap/issues/19402
 
-a:not([href]) {
+a:not([href]):not([tabindex]) {
   color: inherit;
   text-decoration: none;
 
@@ -200,6 +201,8 @@ pre {
   margin-top: 0;
   // Reset browser default of `1em` to use `rem`s
   margin-bottom: 1rem;
+  // Normalize v4 removed this property, causing `<pre>` content to break out of wrapping code snippets
+  overflow: auto;
 }
 
 
@@ -266,6 +269,8 @@ textarea {
 //
 
 table {
+  // No longer part of Normalize since v4
+  border-collapse: collapse;
   // Reset for nesting within parents with `background-color`.
   background-color: $table-bg;
 }
@@ -317,6 +322,29 @@ textarea {
   border-radius: 0;
 }
 
+input[type="radio"],
+input[type="checkbox"] {
+  // Apply a disabled cursor for radios and checkboxes.
+  //
+  // Note: Neither radios nor checkboxes can be readonly.
+  &:disabled {
+    cursor: $cursor-disabled;
+  }
+}
+
+
+input[type="date"],
+input[type="time"],
+input[type="datetime-local"],
+input[type="month"] {
+  // Remove the default appearance of temporal inputs to avoid a Mobile Safari
+  // bug where setting a custom line-height prevents text from being vertically
+  // centered within the input.
+  //
+  // Bug report: https://github.com/twbs/bootstrap/issues/11266
+  -webkit-appearance: listbox;
+}
+
 textarea {
   // Textareas should really only resize vertically so they don't break their (horizontal) containers.
   resize: vertical;
@@ -341,7 +369,6 @@ legend {
   margin-bottom: .5rem;
   font-size: 1.5rem;
   line-height: inherit;
-//  border: 0;
 }
 
 input[type="search"] {
diff --git a/assets/stylesheets/bootstrap/_tables.scss b/assets/stylesheets/bootstrap/_tables.scss
index c04e7c9..d865884 100644
--- a/assets/stylesheets/bootstrap/_tables.scss
+++ b/assets/stylesheets/bootstrap/_tables.scss
@@ -99,24 +99,9 @@
 @include table-row-variant(danger, $state-danger-bg);
 
 
-// Responsive tables
+// Inverse styles
 //
-// Wrap your tables in `.table-responsive` and we'll make them mobile friendly
-// by enabling horizontal scrolling. Only applies <768px. Everything above that
-// will display normally.
-
-.table-responsive {
-  display: block;
-  width: 100%;
-  min-height: .01%; // Workaround for IE9 bug (see https://github.com/twbs/bootstrap/issues/14837)
-  overflow-x: auto;
-
-  // TODO: find out if we need this still.
-  //
-  // border: $table-border-width solid $table-border-color;
-  // -ms-overflow-style: -ms-autohiding-scrollbar; // See https://github.com/twbs/bootstrap/pull/10057
-}
-
+// Same table markup, but inverted color scheme—dark background and light text.
 
 .thead-inverse {
   th {
@@ -124,6 +109,7 @@
     background-color: $gray-dark;
   }
 }
+
 .thead-default {
   th {
     color: $gray;
@@ -135,15 +121,35 @@
   color: $gray-lighter;
   background-color: $gray-dark;
 
-  &.table-bordered {
-    border: 0;
-  }
-
   th,
   td,
   thead th {
     border-color: $gray;
   }
+
+  &.table-bordered {
+    border: 0;
+  }
+}
+
+
+
+// Responsive tables
+//
+// Wrap your tables in `.table-responsive` and we'll make them mobile friendly
+// by enabling horizontal scrolling. Only applies <768px. Everything above that
+// will display normally.
+
+.table-responsive {
+  display: block;
+  width: 100%;
+  min-height: .01%; // Workaround for IE9 bug (see https://github.com/twbs/bootstrap/issues/14837)
+  overflow-x: auto;
+
+  // TODO: find out if we need this still.
+  //
+  // border: $table-border-width solid $table-border-color;
+  // -ms-overflow-style: -ms-autohiding-scrollbar; // See https://github.com/twbs/bootstrap/pull/10057
 }
 
 
diff --git a/assets/stylesheets/bootstrap/_variables.scss b/assets/stylesheets/bootstrap/_variables.scss
index 82ef6f9..d129f9f 100644
--- a/assets/stylesheets/bootstrap/_variables.scss
+++ b/assets/stylesheets/bootstrap/_variables.scss
@@ -49,6 +49,7 @@ $brand-success:             #5cb85c !default;
 $brand-info:                #5bc0de !default;
 $brand-warning:             #f0ad4e !default;
 $brand-danger:              #d9534f !default;
+$brand-inverse:             $gray-dark !default;
 
 
 // Options
@@ -244,8 +245,8 @@ $table-cell-padding:            .75rem !default;
 $table-sm-cell-padding:         .3rem !default;
 
 $table-bg:                      transparent !default;
-$table-bg-accent:               #f9f9f9 !default;
-$table-bg-hover:                #f5f5f5 !default;
+$table-bg-accent:               rgba(0,0,0,.05) !default;
+$table-bg-hover:                rgba(0,0,0,.075) !default;
 $table-bg-active:               $table-bg-hover !default;
 
 $table-border-width:            $border-width !default;
@@ -295,11 +296,8 @@ $btn-padding-y-sm:               .25rem !default;
 $btn-padding-x-lg:               1.5rem !default;
 $btn-padding-y-lg:               .75rem !default;
 
-$btn-block-spacing-y:            5px !default;
-$btn-toolbar-margin:             5px !default;
-
-$split-btn-dropdown-toggle-padding-x:     8px !default;
-$split-btn-lg-dropdown-toggle-padding-x: 12px !default;
+$btn-block-spacing-y:            .5rem !default;
+$btn-toolbar-margin:             .5rem !default;
 
 // Allows for customizing button radius independently from global border radius
 $btn-border-radius:              $border-radius !default;
@@ -325,8 +323,10 @@ $input-border-radius:            $border-radius !default;
 $input-border-radius-lg:         $border-radius-lg !default;
 $input-border-radius-sm:         $border-radius-sm !default;
 
+$input-bg-focus:                 $input-bg;
 $input-border-focus:             #66afe9 !default;
 $input-box-shadow-focus:         rgba(102,175,233,.6) !default;
+$input-color-focus:              $input-color;
 
 $input-color-placeholder:        #999 !default;
 
@@ -382,8 +382,10 @@ $custom-radio-checked-icon: url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='h
 $custom-select-padding-x:          .75rem  !default;
 $custom-select-padding-y:          .375rem !default;
 $custom-select-indicator-padding:  1rem !default; // Extra padding to account for the presence of the background-image based indicator
-$custom-select-color:         $input-color !default;
+$custom-select-color:          $input-color !default;
+$custom-select-disabled-color: $gray-light !default;
 $custom-select-bg:            #fff !default;
+$custom-select-disabled-bg:   $gray-lighter !default;
 $custom-select-bg-size:       8px 10px !default; // In pixels because image dimensions
 $custom-select-indicator:     url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 5'%3E%3Cpath fill='%23333' d='M2 0L0 2h4zm0 5L0 3h4z'/%3E%3C/svg%3E") !default;
 $custom-select-border-width:  $input-btn-border-width !default;
@@ -500,6 +502,7 @@ $nav-disabled-link-hover-bg:    transparent !default;
 
 $nav-tabs-border-color:                       #ddd !default;
 $nav-tabs-border-width:                       $border-width !default;
+$nav-tabs-border-radius:                      $border-radius !default;
 $nav-tabs-link-hover-border-color:            $gray-lighter !default;
 $nav-tabs-active-link-hover-color:            $gray !default;
 $nav-tabs-active-link-hover-bg:               $body-bg !default;
@@ -580,6 +583,8 @@ $card-bg:                  #fff !default;
 
 $card-link-hover-color:    #fff !default;
 
+$card-img-overlay-padding: 1.25rem !default;
+
 $card-deck-margin:         .625rem !default;
 
 $card-columns-sm-up-column-gap: 1.25rem !default;
@@ -601,6 +606,7 @@ $tooltip-arrow-color:         $tooltip-bg !default;
 
 // Popovers
 
+$popover-inner-padding:               1px !default;
 $popover-bg:                          #fff !default;
 $popover-max-width:                   276px !default;
 $popover-border-width:                $border-width !default;
@@ -792,6 +798,8 @@ $carousel-caption-width:                      70% !default;
 $carousel-caption-sm-up-width:                60% !default;
 $carousel-caption-color:                      #fff !default;
 
+$carousel-icon-width:                         20px !default;
+
 
 // Close
 
diff --git a/assets/stylesheets/bootstrap/mixins/_cards.scss b/assets/stylesheets/bootstrap/mixins/_cards.scss
index 1ce28f1..574349a 100644
--- a/assets/stylesheets/bootstrap/mixins/_cards.scss
+++ b/assets/stylesheets/bootstrap/mixins/_cards.scss
@@ -3,6 +3,11 @@
 @mixin card-variant($background, $border) {
   background-color: $background;
   border-color: $border;
+
+  .card-header,
+  .card-footer {
+    background-color: transparent;
+  }
 }
 
 @mixin card-outline-variant($color) {
@@ -17,7 +22,7 @@
 @mixin card-inverse {
   .card-header,
   .card-footer {
-    border-bottom: $card-border-width solid rgba(255,255,255,.2);
+    border-color: rgba(255,255,255,.2);
   }
   .card-header,
   .card-footer,
@@ -27,7 +32,8 @@
   }
   .card-link,
   .card-text,
-  .card-blockquote > footer {
+  .card-subtitle,
+  .card-blockquote .blockquote-footer {
     color: rgba(255,255,255,.65);
   }
   .card-link {
diff --git a/assets/stylesheets/bootstrap/mixins/_forms.scss b/assets/stylesheets/bootstrap/mixins/_forms.scss
index fde8295..026e41e 100644
--- a/assets/stylesheets/bootstrap/mixins/_forms.scss
+++ b/assets/stylesheets/bootstrap/mixins/_forms.scss
@@ -5,7 +5,7 @@
 
 @mixin form-control-validation($color) {
   // Color the label and help text
-  .text-help,
+  .form-control-feedback,
   .form-control-label,
   .radio,
   .checkbox,
@@ -56,6 +56,8 @@
 // contrast against a dark gray background.
 @mixin form-control-focus() {
   &:focus {
+    color: $input-color-focus;
+    background-color: $input-bg-focus;
     border-color: $input-border-focus;
     outline: none;
     $shadow: inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px $input-box-shadow-focus;
diff --git a/assets/stylesheets/bootstrap/mixins/_screen-reader.scss b/assets/stylesheets/bootstrap/mixins/_screen-reader.scss
index e52b282..6ae6551 100644
--- a/assets/stylesheets/bootstrap/mixins/_screen-reader.scss
+++ b/assets/stylesheets/bootstrap/mixins/_screen-reader.scss
@@ -1,6 +1,6 @@
 // Only display content to screen readers
 //
-// See: http://a11yproject.com/posts/how-to-hide-content/
+// See: http://a11yproject.com/posts/how-to-hide-content
 
 @mixin sr-only {
   position: absolute;
diff --git a/assets/stylesheets/bootstrap/utilities/_background.scss b/assets/stylesheets/bootstrap/utilities/_background.scss
index 4bbf731..b158979 100644
--- a/assets/stylesheets/bootstrap/utilities/_background.scss
+++ b/assets/stylesheets/bootstrap/utilities/_background.scss
@@ -2,11 +2,8 @@
 // Contextual backgrounds
 //
 
-// Inverse
-// TODO: redo this as a proper class
 .bg-inverse {
-  color: $gray-lighter;
-  background-color: $gray-dark;
+  background-color: $brand-inverse;
 }
 
 .bg-faded {