Merge branch 'v4' of https://github.com/twbs/derpstrap into v4

Conflicts:
	docs/components/helpers.md
	scss/_utilities.scss

dist/css/bootstrap.css

@@ -1963,7 +1963,7 @@ output {
 .form-control::placeholder {
   color: #999;
 }
-.form-control[disabled], .form-control[readonly], fieldset[disabled] .form-control {
+.form-control:disabled, .form-control[readonly], fieldset[disabled] .form-control {
   cursor: not-allowed;
   background-color: #eceeef;
   opacity: 1;
@@ -2035,7 +2035,7 @@ input[type="search"] {
   margin-left: 10px;
 }
 
-input[type="radio"][disabled], input[type="radio"].disabled, fieldset[disabled] input[type="radio"], input[type="checkbox"][disabled], input[type="checkbox"].disabled, fieldset[disabled] input[type="checkbox"] {
+input[type="radio"]:disabled, input[type="radio"].disabled, fieldset[disabled] input[type="radio"], input[type="checkbox"]:disabled, input[type="checkbox"].disabled, fieldset[disabled] input[type="checkbox"] {
   cursor: not-allowed;
 }
 
@@ -2364,7 +2364,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn.disabled, .btn[disabled], fieldset[disabled] .btn {
+.btn.disabled, .btn:disabled, fieldset[disabled] .btn {
   pointer-events: none;
   cursor: not-allowed;
   -webkit-box-shadow: none;
@@ -2387,7 +2387,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn-primary.disabled, .btn-primary.disabled:hover, .btn-primary.disabled:focus, .btn-primary.disabled.focus, .btn-primary.disabled:active, .btn-primary.disabled.active, .btn-primary[disabled], .btn-primary[disabled]:hover, .btn-primary[disabled]:focus, .btn-primary[disabled].focus, .btn-primary[disabled]:active, .btn-primary[disabled].active, fieldset[disabled] .btn-primary, fieldset[disabled] .btn-primary:hover, fieldset[disabled] .btn-primary:focus, fieldset[disabled] .btn-primary.focus, fieldset[disabled] .btn-primary:active, fieldset[disabled] .btn-primary.active {
+.btn-primary.disabled, .btn-primary.disabled:hover, .btn-primary.disabled:focus, .btn-primary.disabled.focus, .btn-primary.disabled:active, .btn-primary.disabled.active, .btn-primary:disabled, .btn-primary:disabled:hover, .btn-primary:disabled:focus, .btn-primary:disabled.focus, .btn-primary:disabled:active, .btn-primary:disabled.active, fieldset[disabled] .btn-primary, fieldset[disabled] .btn-primary:hover, fieldset[disabled] .btn-primary:focus, fieldset[disabled] .btn-primary.focus, fieldset[disabled] .btn-primary:active, fieldset[disabled] .btn-primary.active {
   background-color: #0275d8;
   border-color: #0267bf;
 }
@@ -2411,7 +2411,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn-secondary.disabled, .btn-secondary.disabled:hover, .btn-secondary.disabled:focus, .btn-secondary.disabled.focus, .btn-secondary.disabled:active, .btn-secondary.disabled.active, .btn-secondary[disabled], .btn-secondary[disabled]:hover, .btn-secondary[disabled]:focus, .btn-secondary[disabled].focus, .btn-secondary[disabled]:active, .btn-secondary[disabled].active, fieldset[disabled] .btn-secondary, fieldset[disabled] .btn-secondary:hover, fieldset[disabled] .btn-secondary:focus, fieldset[disabled] .btn-secondary.focus, fieldset[disabled] .btn-secondary:active, fieldset[disabled] .btn-secondary.active {
+.btn-secondary.disabled, .btn-secondary.disabled:hover, .btn-secondary.disabled:focus, .btn-secondary.disabled.focus, .btn-secondary.disabled:active, .btn-secondary.disabled.active, .btn-secondary:disabled, .btn-secondary:disabled:hover, .btn-secondary:disabled:focus, .btn-secondary:disabled.focus, .btn-secondary:disabled:active, .btn-secondary:disabled.active, fieldset[disabled] .btn-secondary, fieldset[disabled] .btn-secondary:hover, fieldset[disabled] .btn-secondary:focus, fieldset[disabled] .btn-secondary.focus, fieldset[disabled] .btn-secondary:active, fieldset[disabled] .btn-secondary.active {
   background-color: #fff;
   border-color: #eceeef;
 }
@@ -2435,7 +2435,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn-info.disabled, .btn-info.disabled:hover, .btn-info.disabled:focus, .btn-info.disabled.focus, .btn-info.disabled:active, .btn-info.disabled.active, .btn-info[disabled], .btn-info[disabled]:hover, .btn-info[disabled]:focus, .btn-info[disabled].focus, .btn-info[disabled]:active, .btn-info[disabled].active, fieldset[disabled] .btn-info, fieldset[disabled] .btn-info:hover, fieldset[disabled] .btn-info:focus, fieldset[disabled] .btn-info.focus, fieldset[disabled] .btn-info:active, fieldset[disabled] .btn-info.active {
+.btn-info.disabled, .btn-info.disabled:hover, .btn-info.disabled:focus, .btn-info.disabled.focus, .btn-info.disabled:active, .btn-info.disabled.active, .btn-info:disabled, .btn-info:disabled:hover, .btn-info:disabled:focus, .btn-info:disabled.focus, .btn-info:disabled:active, .btn-info:disabled.active, fieldset[disabled] .btn-info, fieldset[disabled] .btn-info:hover, fieldset[disabled] .btn-info:focus, fieldset[disabled] .btn-info.focus, fieldset[disabled] .btn-info:active, fieldset[disabled] .btn-info.active {
   background-color: #5bc0de;
   border-color: #46b8da;
 }
@@ -2459,7 +2459,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn-success.disabled, .btn-success.disabled:hover, .btn-success.disabled:focus, .btn-success.disabled.focus, .btn-success.disabled:active, .btn-success.disabled.active, .btn-success[disabled], .btn-success[disabled]:hover, .btn-success[disabled]:focus, .btn-success[disabled].focus, .btn-success[disabled]:active, .btn-success[disabled].active, fieldset[disabled] .btn-success, fieldset[disabled] .btn-success:hover, fieldset[disabled] .btn-success:focus, fieldset[disabled] .btn-success.focus, fieldset[disabled] .btn-success:active, fieldset[disabled] .btn-success.active {
+.btn-success.disabled, .btn-success.disabled:hover, .btn-success.disabled:focus, .btn-success.disabled.focus, .btn-success.disabled:active, .btn-success.disabled.active, .btn-success:disabled, .btn-success:disabled:hover, .btn-success:disabled:focus, .btn-success:disabled.focus, .btn-success:disabled:active, .btn-success:disabled.active, fieldset[disabled] .btn-success, fieldset[disabled] .btn-success:hover, fieldset[disabled] .btn-success:focus, fieldset[disabled] .btn-success.focus, fieldset[disabled] .btn-success:active, fieldset[disabled] .btn-success.active {
   background-color: #5cb85c;
   border-color: #4cae4c;
 }
@@ -2483,7 +2483,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn-warning.disabled, .btn-warning.disabled:hover, .btn-warning.disabled:focus, .btn-warning.disabled.focus, .btn-warning.disabled:active, .btn-warning.disabled.active, .btn-warning[disabled], .btn-warning[disabled]:hover, .btn-warning[disabled]:focus, .btn-warning[disabled].focus, .btn-warning[disabled]:active, .btn-warning[disabled].active, fieldset[disabled] .btn-warning, fieldset[disabled] .btn-warning:hover, fieldset[disabled] .btn-warning:focus, fieldset[disabled] .btn-warning.focus, fieldset[disabled] .btn-warning:active, fieldset[disabled] .btn-warning.active {
+.btn-warning.disabled, .btn-warning.disabled:hover, .btn-warning.disabled:focus, .btn-warning.disabled.focus, .btn-warning.disabled:active, .btn-warning.disabled.active, .btn-warning:disabled, .btn-warning:disabled:hover, .btn-warning:disabled:focus, .btn-warning:disabled.focus, .btn-warning:disabled:active, .btn-warning:disabled.active, fieldset[disabled] .btn-warning, fieldset[disabled] .btn-warning:hover, fieldset[disabled] .btn-warning:focus, fieldset[disabled] .btn-warning.focus, fieldset[disabled] .btn-warning:active, fieldset[disabled] .btn-warning.active {
   background-color: #f0ad4e;
   border-color: #eea236;
 }
@@ -2507,7 +2507,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   -webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
           box-shadow: inset 0 3px 5px rgba(0, 0, 0, .125);
 }
-.btn-danger.disabled, .btn-danger.disabled:hover, .btn-danger.disabled:focus, .btn-danger.disabled.focus, .btn-danger.disabled:active, .btn-danger.disabled.active, .btn-danger[disabled], .btn-danger[disabled]:hover, .btn-danger[disabled]:focus, .btn-danger[disabled].focus, .btn-danger[disabled]:active, .btn-danger[disabled].active, fieldset[disabled] .btn-danger, fieldset[disabled] .btn-danger:hover, fieldset[disabled] .btn-danger:focus, fieldset[disabled] .btn-danger.focus, fieldset[disabled] .btn-danger:active, fieldset[disabled] .btn-danger.active {
+.btn-danger.disabled, .btn-danger.disabled:hover, .btn-danger.disabled:focus, .btn-danger.disabled.focus, .btn-danger.disabled:active, .btn-danger.disabled.active, .btn-danger:disabled, .btn-danger:disabled:hover, .btn-danger:disabled:focus, .btn-danger:disabled.focus, .btn-danger:disabled:active, .btn-danger:disabled.active, fieldset[disabled] .btn-danger, fieldset[disabled] .btn-danger:hover, fieldset[disabled] .btn-danger:focus, fieldset[disabled] .btn-danger.focus, fieldset[disabled] .btn-danger:active, fieldset[disabled] .btn-danger.active {
   background-color: #d9534f;
   border-color: #d43f3a;
 }
@@ -2521,7 +2521,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   color: #0275d8;
   border-radius: 0;
 }
-.btn-link, .btn-link:active, .btn-link.active, .btn-link[disabled], fieldset[disabled] .btn-link {
+.btn-link, .btn-link:active, .btn-link.active, .btn-link:disabled, fieldset[disabled] .btn-link {
   background-color: transparent;
   -webkit-box-shadow: none;
           box-shadow: none;
@@ -2534,7 +2534,7 @@ textarea.input-lg, .input-group-lg > textarea.form-control, .input-group-lg > te
   text-decoration: underline;
   background-color: transparent;
 }
-.btn-link[disabled]:hover, .btn-link[disabled]:focus, fieldset[disabled] .btn-link:hover, fieldset[disabled] .btn-link:focus {
+.btn-link:disabled:hover, .btn-link:disabled:focus, fieldset[disabled] .btn-link:hover, fieldset[disabled] .btn-link:focus {
   color: #818a91;
   text-decoration: none;
 }
@@ -3308,7 +3308,7 @@ input[type="submit"].btn-block, input[type="reset"].btn-block, input[type="butto
 .navbar-default .btn-link:hover, .navbar-default .btn-link:focus {
   color: #333;
 }
-.navbar-default .btn-link[disabled]:hover, .navbar-default .btn-link[disabled]:focus, fieldset[disabled] .navbar-default .btn-link:hover, fieldset[disabled] .navbar-default .btn-link:focus {
+.navbar-default .btn-link:disabled:hover, .navbar-default .btn-link:disabled:focus, fieldset[disabled] .navbar-default .btn-link:hover, fieldset[disabled] .navbar-default .btn-link:focus {
   color: #ccc;
 }
 
@@ -3374,7 +3374,7 @@ input[type="submit"].btn-block, input[type="reset"].btn-block, input[type="butto
 .navbar-inverse .btn-link:hover, .navbar-inverse .btn-link:focus {
   color: #fff;
 }
-.navbar-inverse .btn-link[disabled]:hover, .navbar-inverse .btn-link[disabled]:focus, fieldset[disabled] .navbar-inverse .btn-link:hover, fieldset[disabled] .navbar-inverse .btn-link:focus {
+.navbar-inverse .btn-link:disabled:hover, .navbar-inverse .btn-link:disabled:focus, fieldset[disabled] .navbar-inverse .btn-link:hover, fieldset[disabled] .navbar-inverse .btn-link:focus {
   color: #444;
 }
 

scss/_buttons.scss

@@ -43,7 +43,7 @@
   }
 
   &.disabled,
-  &[disabled],
+  &:disabled,
   fieldset[disabled] & {
     pointer-events: none; // Future-proof disabling of clicks
     cursor: $cursor-disabled;
@@ -88,7 +88,7 @@
   &,
   &:active,
   &.active,
-  &[disabled],
+  &:disabled,
   fieldset[disabled] & {
     background-color: transparent;
     @include box-shadow(none);
@@ -105,7 +105,7 @@
     text-decoration: underline;
     background-color: transparent;
   }
-  &[disabled],
+  &:disabled,
   fieldset[disabled] & {
     &:hover,
     &:focus {

scss/_forms.scss

@@ -133,6 +133,7 @@ output {
   // Placeholder
   &::placeholder {
     color: $input-color-placeholder;
+    opacity: 1; // Override Firefox's unusual default opacity; see https://github.com/twbs/bootstrap/pull/11526
   }
 
   // Disabled and read-only inputs
@@ -140,7 +141,7 @@ output {
   // HTML5 says that controls under a fieldset > legend:first-child won't be
   // disabled if the fieldset is disabled. Due to implementation difficulty, we
   // don't honor that edge case; we style them as disabled anyway.
-  &[disabled],
+  &:disabled,
   &[readonly],
   fieldset[disabled] & {
     cursor: $cursor-disabled;
@@ -263,7 +264,7 @@ input[type="search"] {
 // Note: Neither radios nor checkboxes can be readonly.
 input[type="radio"],
 input[type="checkbox"] {
-  &[disabled],
+  &:disabled,
   &.disabled,
   fieldset[disabled] & {
     cursor: $cursor-disabled;

scss/_navbar.scss

@@ -309,7 +309,7 @@
     &:focus {
       color: $navbar-default-link-hover-color;
     }
-    &[disabled],
+    &:disabled,
     fieldset[disabled] & {
       &:hover,
       &:focus {
@@ -422,7 +422,7 @@
       color: $navbar-inverse-link-hover-color;
     }
 
-    &[disabled],
+    &:disabled,
     fieldset[disabled] & {
       &:hover,
       &:focus {

scss/_utilities.scss

@@ -46,12 +46,6 @@
   z-index: $zindex-navbar-fixed;
 }
 
-
-// Toggling content
-.show {
-  display: block !important;
-}
-
 // Always hide an element with the `hidden` HTML attribute (from PureCSS).
 [hidden] {
   display: none !important;
@@ -66,15 +60,6 @@
 }
 
 
-// Hide from screenreaders and browsers
-//
-// Credit: HTML5 Boilerplate
-.hidden {
-  display: none !important;
-  visibility: hidden !important;
-}
-
-
 // For Affix plugin
 .affix {
   position: fixed;

scss/mixins/_buttons.scss

@@ -28,7 +28,7 @@
     @include box-shadow(inset 0 3px 5px rgba(0,0,0,.125));
   }
   &.disabled,
-  &[disabled],
+  &:disabled,
   fieldset[disabled] & {
     &,
     &:hover,

scss/mixins/_image.scss

@@ -16,15 +16,13 @@
 
 // Retina image
 //
-// Short retina mixin for setting background-image and -size. Note that the
-// spelling of `min--moz-device-pixel-ratio` is intentional.
+// Short retina mixin for setting background-image and -size.
 
 @mixin img-retina($file-1x, $file-2x, $width-1x, $height-1x) {
   background-image: url("#{file-1x}");
 
   @media
   only screen and (-webkit-min-device-pixel-ratio: 2),
-  only screen and (   min--moz-device-pixel-ratio: 2),
   only screen and (     -o-min-device-pixel-ratio: 2/1),
   only screen and (        min-device-pixel-ratio: 2),
   only screen and (                min-resolution: 192dpi),