Merge branch 'v4-dev' into carousel

8 files changed, 100 insertions, 97 deletions

diff --git a/docs/components/card.md b/docs/components/card.md
index f876ccad2..7d350708c 100644
--- a/docs/components/card.md
+++ b/docs/components/card.md
@@ -151,13 +151,13 @@ You can quickly change the text alignment of any card—in its entirety or speci
   <a href="#" class="btn btn-primary">Go somewhere</a>
 </div>
 
-<div class="card card-block text-xs-center">
+<div class="card card-block text-center">
   <h4 class="card-title">Special title treatment</h4>
   <p class="card-text">With supporting text below as a natural lead-in to additional content.</p>
   <a href="#" class="btn btn-primary">Go somewhere</a>
 </div>
 
-<div class="card card-block text-xs-right">
+<div class="card card-block text-right">
   <h4 class="card-title">Special title treatment</h4>
   <p class="card-text">With supporting text below as a natural lead-in to additional content.</p>
   <a href="#" class="btn btn-primary">Go somewhere</a>
@@ -209,7 +209,7 @@ Card headers can be styled by adding `.card-header` to `<h*>` elements.
 {% endexample %}
 
 {% example html %}
-<div class="card text-xs-center">
+<div class="card text-center">
   <div class="card-header">
     Featured
   </div>
@@ -229,7 +229,7 @@ Card headers can be styled by adding `.card-header` to `<h*>` elements.
 Use Bootstrap's nav pills or tabs within a card header. Be sure to always include a `.float-*-*` utility class for proper alignment.
 
 {% example html %}
-<div class="card text-xs-center">
+<div class="card text-center">
   <div class="card-header">
     <ul class="nav nav-tabs card-header-tabs float-left">
       <li class="nav-item">
@@ -252,7 +252,7 @@ Use Bootstrap's nav pills or tabs within a card header. Be sure to always includ
 {% endexample %}
 
 {% example html %}
-<div class="card text-xs-center">
+<div class="card text-center">
   <div class="card-header">
     <ul class="nav nav-pills card-header-pills float-left">
       <li class="nav-item">
@@ -314,7 +314,7 @@ Turn an image into a card background and overlay your card's text. Depending on
 
 ## Inverted text
 
-Cards include a class for quickly toggling **the text color**. By default, cards use dark text and assume a light background. **Add `.card-inverse` for white text** and specify the `background-color` and `border-color` to go with it.
+By default, cards use dark text and assume a light background. You can reverse that by toggling the `color` of text within, as well as that of the card's subcomponents, with `.card-inverse`. Then, specify a dark `background-color` and `border-color` to go with it.
 
 You can also use `.card-inverse` with the [contextual backgrounds variants](#background-variants).
 
@@ -333,7 +333,7 @@ You can also use `.card-inverse` with the [contextual backgrounds variants](#bac
 Cards include their own variant classes for quickly changing the `background-color` and `border-color` of a card. **Darker colors require the use of `.card-inverse`.**
 
 {% example html %}
-<div class="card card-inverse card-primary text-xs-center">
+<div class="card card-inverse card-primary text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -341,7 +341,7 @@ Cards include their own variant classes for quickly changing the `background-col
     </blockquote>
   </div>
 </div>
-<div class="card card-inverse card-success text-xs-center">
+<div class="card card-inverse card-success text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -349,7 +349,7 @@ Cards include their own variant classes for quickly changing the `background-col
     </blockquote>
   </div>
 </div>
-<div class="card card-inverse card-info text-xs-center">
+<div class="card card-inverse card-info text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -357,7 +357,7 @@ Cards include their own variant classes for quickly changing the `background-col
     </blockquote>
   </div>
 </div>
-<div class="card card-inverse card-warning text-xs-center">
+<div class="card card-inverse card-warning text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -365,7 +365,7 @@ Cards include their own variant classes for quickly changing the `background-col
     </blockquote>
   </div>
 </div>
-<div class="card card-inverse card-danger text-xs-center">
+<div class="card card-inverse card-danger text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -383,7 +383,7 @@ Cards include their own variant classes for quickly changing the `background-col
 In need of a colored card, but not the hefty background colors they bring? Replace the default modifier classes with the `.card-outline-*` ones to style just the `border-color` of a card.
 
 {% example html %}
-<div class="card card-outline-primary text-xs-center">
+<div class="card card-outline-primary text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -391,7 +391,7 @@ In need of a colored card, but not the hefty background colors they bring? Repla
     </blockquote>
   </div>
 </div>
-<div class="card card-outline-secondary text-xs-center">
+<div class="card card-outline-secondary text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -399,7 +399,7 @@ In need of a colored card, but not the hefty background colors they bring? Repla
     </blockquote>
   </div>
 </div>
-<div class="card card-outline-success text-xs-center">
+<div class="card card-outline-success text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -407,7 +407,7 @@ In need of a colored card, but not the hefty background colors they bring? Repla
     </blockquote>
   </div>
 </div>
-<div class="card card-outline-info text-xs-center">
+<div class="card card-outline-info text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -415,7 +415,7 @@ In need of a colored card, but not the hefty background colors they bring? Repla
     </blockquote>
   </div>
 </div>
-<div class="card card-outline-warning text-xs-center">
+<div class="card card-outline-warning text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -423,7 +423,7 @@ In need of a colored card, but not the hefty background colors they bring? Repla
     </blockquote>
   </div>
 </div>
-<div class="card card-outline-danger text-xs-center">
+<div class="card card-outline-danger text-center">
   <div class="card-block">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
@@ -542,7 +542,7 @@ Only applies to small devices and above.
       <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
     </div>
   </div>
-  <div class="card card-block card-inverse card-primary text-xs-center">
+  <div class="card card-block card-inverse card-primary text-center">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat.</p>
       <footer>
@@ -552,7 +552,7 @@ Only applies to small devices and above.
       </footer>
     </blockquote>
   </div>
-  <div class="card card-block text-xs-center">
+  <div class="card card-block text-center">
     <h4 class="card-title">Card title</h4>
     <p class="card-text">This card has supporting text below as a natural lead-in to additional content.</p>
     <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
@@ -560,7 +560,7 @@ Only applies to small devices and above.
   <div class="card">
     <img class="card-img img-fluid" data-src="holder.js/100px260/" alt="Card image">
   </div>
-  <div class="card card-block text-xs-right">
+  <div class="card card-block text-right">
     <blockquote class="card-blockquote">
       <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.</p>
       <footer>
diff --git a/docs/components/forms.md b/docs/components/forms.md
index 8915c9e7b..4cbf20412 100644
--- a/docs/components/forms.md
+++ b/docs/components/forms.md
@@ -152,8 +152,7 @@ Below is a complete list of the specific form controls supported by Bootstrap an
     <tr>
       <td class="text-nowrap">
 {% markdown %}
-`.form-check`<br>
-`.form-check-inline`
+`.form-check`
 {% endmarkdown %}
       </td>
       <td class="text-nowrap">
@@ -274,62 +273,54 @@ The `.form-group` class is the easiest way to add some structure to forms. Its o
 
 ### Inline forms
 
-Use the `.form-inline` class to display a series of labels, form controls, and buttons on a single horizontal row. Form controls within inline forms behave differently:
+Use the `.form-inline` class to display a series of labels, form controls, and buttons on a single horizontal row. Form controls within inline forms vary slightly from their default states.
 
-- Controls are `display: inline-block` to provide alignment control via `vertical-align` and `margin`.
-- Controls receive `width: auto` to override the Bootstrap default `width: 100%`.
-- Controls **only appear inline in viewports that are at least 768px wide** to account for narrow viewports on mobile devices.
+- Controls are `display: inline-block` (or `flex` when enabled) to provide alignment control via `vertical-align` and `margin`. Those also means you'll have some HTML character spaces between elements by default.
+- Controls and input groups receive `width: auto` to override the Bootstrap default `width: 100%`.
+- Controls **only appear inline in viewports that are at least 576px wide** to account for narrow viewports on mobile devices.
 
-Because of this, you may need to manually address the width and alignment of individual form controls. Lastly, as shown below, you should always include a `<label>` with each form control.
-
-#### Visible labels
+You may need to manually address the width and alignment of individual form controls with [spacing utilities]({{ site.baseurl }}/utilities/spacing/) (as shown below). Lastly, be sure to always include a `<label>` with each form control, even if you need to hide it from non-screenreader visitors with `.sr-only`.
 
 {% example html %}
 <form class="form-inline">
-  <div class="form-group">
-    <label for="exampleInputName2">Name</label>
-    <input type="text" class="form-control" id="exampleInputName2" placeholder="Jane Doe">
-  </div>
-  <div class="form-group">
-    <label for="exampleInputEmail2">Email</label>
-    <input type="email" class="form-control" id="exampleInputEmail2" placeholder="[email protected]">
-  </div>
-  <button type="submit" class="btn btn-primary">Send invitation</button>
-</form>
-{% endexample %}
+  <label class="sr-only" for="inlineFormInput">Name</label>
+  <input type="text" class="form-control mb-2 mr-sm-2 mb-sm-0" id="inlineFormInput" placeholder="Jane Doe">
 
-#### Hidden labels
-
-{% example html %}
-<form class="form-inline">
-  <div class="form-group">
-    <label class="sr-only" for="exampleInputEmail3">Email address</label>
-    <input type="email" class="form-control" id="exampleInputEmail3" placeholder="Enter email">
-  </div>
-  <div class="form-group">
-    <label class="sr-only" for="exampleInputPassword3">Password</label>
-    <input type="password" class="form-control" id="exampleInputPassword3" placeholder="Password">
+  <label class="sr-only" for="inlineFormInputGroup">Username</label>
+  <div class="input-group mb-2 mr-sm-2 mb-sm-0">
+    <div class="input-group-addon">@</div>
+    <input type="text" class="form-control" id="inlineFormInputGroup" placeholder="Username">
   </div>
-  <div class="form-check">
+
+  <div class="form-check mb-2 mr-sm-2 mb-sm-0">
     <label class="form-check-label">
       <input class="form-check-input" type="checkbox"> Remember me
     </label>
   </div>
-  <button type="submit" class="btn btn-primary">Sign in</button>
+
+  <button type="submit" class="btn btn-primary">Submit</button>
 </form>
 {% endexample %}
 
+Custom form controls and selects are also supported.
+
 {% example html %}
 <form class="form-inline">
-  <div class="form-group">
-    <label class="sr-only" for="exampleInputAmount">Amount (in dollars)</label>
-    <div class="input-group">
-      <div class="input-group-addon">$</div>
-      <input type="text" class="form-control" id="exampleInputAmount" placeholder="Amount">
-      <div class="input-group-addon">.00</div>
-    </div>
-  </div>
-  <button type="submit" class="btn btn-primary">Transfer cash</button>
+  <label class="mr-sm-2" for="inlineFormCustomSelect">Preference</label>
+  <select class="custom-select mb-2 mr-sm-2 mb-sm-0" id="inlineFormCustomSelect">
+    <option selected>Choose...</option>
+    <option value="1">One</option>
+    <option value="2">Two</option>
+    <option value="3">Three</option>
+  </select>
+
+  <label class="custom-control custom-checkbox mb-2 mr-sm-2 mb-sm-0">
+    <input type="checkbox" class="custom-control-input">
+    <span class="custom-control-indicator"></span>
+    <span class="custom-control-description">Remember my preference</span>
+  </label>
+
+  <button type="submit" class="btn btn-primary">Submit</button>
 </form>
 {% endexample %}
 
@@ -471,30 +462,42 @@ By default, any number of checkboxes and radios that are immediate sibling will
 
 ### Inline
 
-Groups of checkboxes or radios that appear on the same horizontal row are similar to their stacked counterparts, but require different HTML and a single class. To switch from stacked to inline, drop the surrounding `<div>`, add `.form-check-inline` to the `<label>`, and keep the `.form-check-input` on the `<input>`.
+Group checkboxes or radios on the same horizontal row by adding `.form-check-inline` to any `.form-check`.
 
 {% example html %}
-<label class="form-check-inline">
-  <input class="form-check-input" type="checkbox" id="inlineCheckbox1" value="option1"> 1
-</label>
-<label class="form-check-inline">
-  <input class="form-check-input" type="checkbox" id="inlineCheckbox2" value="option2"> 2
-</label>
-<label class="form-check-inline">
-  <input class="form-check-input" type="checkbox" id="inlineCheckbox3" value="option3"> 3
-</label>
+<div class="form-check form-check-inline">
+  <label class="form-check-label">
+    <input class="form-check-input" type="checkbox" id="inlineCheckbox1" value="option1"> 1
+  </label>
+</div>
+<div class="form-check form-check-inline">
+  <label class="form-check-label">
+    <input class="form-check-input" type="checkbox" id="inlineCheckbox2" value="option2"> 2
+  </label>
+</div>
+<div class="form-check form-check-inline disabled">
+  <label class="form-check-label">
+    <input class="form-check-input" type="checkbox" id="inlineCheckbox3" value="option3" disabled> 3
+  </label>
+</div>
 {% endexample %}
 
 {% example html %}
-<label class="form-check-inline">
-  <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio1" value="option1"> 1
-</label>
-<label class="form-check-inline">
-  <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio2" value="option2"> 2
-</label>
-<label class="form-check-inline">
-  <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio3" value="option3"> 3
-</label>
+<div class="form-check form-check-inline">
+  <label class="form-check-label">
+    <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio1" value="option1"> 1
+  </label>
+</div>
+<div class="form-check form-check-inline">
+  <label class="form-check-label">
+    <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio2" value="option2"> 2
+  </label>
+</div>
+<div class="form-check form-check-inline disabled">
+  <label class="form-check-label">
+    <input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio3" value="option3" disabled> 3
+  </label>
+</div>
 {% endexample %}
 
 ### Without labels
diff --git a/docs/components/list-group.md b/docs/components/list-group.md
index 49a6ced63..820470bbb 100644
--- a/docs/components/list-group.md
+++ b/docs/components/list-group.md
@@ -46,19 +46,19 @@ Add badges to any list group item to show unread counts, activity, etc.
 </ul>
 {% endexample %}
 
-When in flexbox mode, you'll need to rearrange the contents of your list group items. To replicate the right-aligned badges as shown above, use the following example's code. Note the [`flex-items-xs-between` utility class]({{ site.baseurl }}/layout/flexbox-grid/#horizontal-alignment), the badge's placement, and the lack of a float utility on the badges.
+When in flexbox mode, you'll need to rearrange the contents of your list group items. To replicate the right-aligned badges as shown above, use the following example's code. Note the [`flex-items-between` utility class]({{ site.baseurl }}/layout/flexbox-grid/#horizontal-alignment), the badge's placement, and the lack of a float utility on the badges.
 
 {% highlight html %}
 <ul class="list-group">
-  <li class="list-group-item flex-items-xs-between">
+  <li class="list-group-item flex-items-between">
     Cras justo odio
     <span class="badge badge-default badge-pill">14</span>
   </li>
-  <li class="list-group-item flex-items-xs-between">
+  <li class="list-group-item flex-items-between">
     Dapibus ac facilisis in
     <span class="badge badge-default badge-pill">2</span>
   </li>
-  <li class="list-group-item flex-items-xs-between">
+  <li class="list-group-item flex-items-between">
     Morbi leo risus
     <span class="badge badge-default badge-pill">1</span>
   </li>
diff --git a/docs/components/modal.md b/docs/components/modal.md
index 9c3746116..5b482f93b 100644
--- a/docs/components/modal.md
+++ b/docs/components/modal.md
@@ -29,7 +29,7 @@ Be sure not to open a modal while another is still visible. Showing more than on
 {% callout warning %}
 #### Modal markup placement
 
-Always try to place a modal's HTML code in a top-level position in your document to avoid other components affecting the modal's appearance and/or functionality.
+Always try to place a modal's HTML code in a top-level position in your document to avoid other components affecting the modal's appearance and/or functionality. Placing it within a `position: fixed;` element may adversely affect placement.
 {% endcallout %}
 
 {% callout warning %}
diff --git a/docs/components/navbar.md b/docs/components/navbar.md
index 34fb6f28b..06a90a212 100644
--- a/docs/components/navbar.md
+++ b/docs/components/navbar.md
@@ -44,7 +44,7 @@ Here's an example of all the sub-components included in a default, non-responsiv
       <a class="nav-link" href="#">Link</a>
     </li>
     <li class="nav-item">
-      <a class="nav-link" href="#">Link</a>
+      <a class="nav-link disabled" href="#">Disabled</a>
     </li>
     <li class="nav-item dropdown">
       <a class="nav-link dropdown-toggle" href="http://example.com" id="supportedContentDropdown" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
@@ -118,7 +118,7 @@ Active states—with `.active`—to indicate the current page can be applied dir
       <a class="nav-link" href="#">Pricing</a>
     </li>
     <li class="nav-item">
-      <a class="nav-link" href="#">About</a>
+      <a class="nav-link disabled" href="#">Disabled</a>
     </li>
   </ul>
 </nav>
@@ -132,7 +132,7 @@ And because we use classes for our navs, you can avoid the list-based approach e
     <a class="nav-item nav-link active" href="#">Home <span class="sr-only">(current)</span></a>
     <a class="nav-item nav-link" href="#">Features</a>
     <a class="nav-item nav-link" href="#">Pricing</a>
-    <a class="nav-item nav-link" href="#">About</a>
+    <a class="nav-item nav-link disabled" href="#">Disabled</a>
   </div>
 </nav>
 {% endexample %}
diff --git a/docs/components/navs.md b/docs/components/navs.md
index 86fd0463f..7ac1b5232 100644
--- a/docs/components/navs.md
+++ b/docs/components/navs.md
@@ -282,7 +282,7 @@ And pills, too:
 Using our [flexbox utilities]({{ site.baseurl }}/layout/flexbox-grid/#horizontal-alignment), you can also customize your navigation components to change the alignment of nav items. For example, here are center aligned links on the inline nav component.
 
 {% example html %}
-<ul class="nav nav-inline d-flex flex-items-xs-center">
+<ul class="nav nav-inline d-flex flex-items-center">
   <li class="nav-item">
     <a class="nav-link active" href="#">Active</a>
   </li>
diff --git a/docs/components/progress.md b/docs/components/progress.md
index 2d8db33cb..50d1f1b55 100644
--- a/docs/components/progress.md
+++ b/docs/components/progress.md
@@ -18,19 +18,19 @@ To caption a progress bar, simply add a `<div>` with your caption text, [align t
 
 {% example html %}
 
-<div class="text-xs-center" id="example-caption-1">Reticulating splines&hellip; 0%</div>
+<div class="text-center" id="example-caption-1">Reticulating splines&hellip; 0%</div>
 <progress class="progress" value="0" max="100" aria-describedby="example-caption-1"></progress>
 
-<div class="text-xs-center" id="example-caption-2">Reticulating splines&hellip; 25%</div>
+<div class="text-center" id="example-caption-2">Reticulating splines&hellip; 25%</div>
 <progress class="progress" value="25" max="100" aria-describedby="example-caption-2"></progress>
 
-<div class="text-xs-center" id="example-caption-3">Reticulating splines&hellip; 50%</div>
+<div class="text-center" id="example-caption-3">Reticulating splines&hellip; 50%</div>
 <progress class="progress" value="50" max="100" aria-describedby="example-caption-3"></progress>
 
-<div class="text-xs-center" id="example-caption-4">Reticulating splines&hellip; 75%</div>
+<div class="text-center" id="example-caption-4">Reticulating splines&hellip; 75%</div>
 <progress class="progress" value="75" max="100" aria-describedby="example-caption-4"></progress>
 
-<div class="text-xs-center" id="example-caption-5">Reticulating splines&hellip; 100%</div>
+<div class="text-center" id="example-caption-5">Reticulating splines&hellip; 100%</div>
 <progress class="progress" value="100" max="100" aria-describedby="example-caption-5"></progress>
 {% endexample %}
 
@@ -39,7 +39,7 @@ To caption a progress bar, simply add a `<div>` with your caption text, [align t
 Internet Explorer 9 doesn't support the HTML5 `<progress>` element, but we can work around that.
 
 {% example html %}
-<div class="text-xs-center" id="example-caption-6">Reticulating splines&hellip; 25%</div>
+<div class="text-center" id="example-caption-6">Reticulating splines&hellip; 25%</div>
 <progress class="progress" value="25" max="100" aria-describedby="example-caption-6">
   <div class="progress">
     <span class="progress-bar" style="width: 25%;"></span>
diff --git a/docs/components/tooltips.md b/docs/components/tooltips.md
index b6dc451ec..31fb2c1c7 100644
--- a/docs/components/tooltips.md
+++ b/docs/components/tooltips.md
@@ -165,7 +165,7 @@ Options can be passed via data attributes or JavaScript. For data attributes, ap
       </tr>
       <tr>
         <td>container</td>
-        <td>string | false</td>
+        <td>string | element | false</td>
         <td>false</td>
         <td>
           <p>Appends the tooltip to a specific element. Example: <code>container: 'body'</code>. This option is particularly useful in that it allows you to position the tooltip in the flow of the document near the triggering element - which will prevent the tooltip from floating away from the triggering element during a window resize.</p>