Fix broken URI fragments and redirects.

10 files changed, 13 insertions, 13 deletions

diff --git a/docs/4.0/about/overview.md b/docs/4.0/about/overview.md
index 1c5386aa98..2d53dd9f1c 100644
--- a/docs/4.0/about/overview.md
+++ b/docs/4.0/about/overview.md
@@ -19,7 +19,7 @@ Originally created by a designer and a developer at Twitter, Bootstrap has becom
 
 Bootstrap was created at Twitter in mid-2010 by [@mdo](https://twitter.com/mdo) and [@fat](https://twitter.com/fat). Prior to being an open-sourced framework, Bootstrap was known as _Twitter Blueprint_. A few months into development, Twitter held its [first Hack Week](https://blog.twitter.com/2010/hack-week) and the project exploded as developers of all skill levels jumped in without any external guidance. It served as the style guide for internal tools development at the company for over a year before its public release, and continues to do so today.
 
-Originally [released](https://blog.twitter.com/2011/bootstrap-from-twitter) on [<time datetime="2011-08-19 11:25">Friday, August 19, 2011</time>](https://twitter.com/mdo/statuses/104620039650557952), we've since had over [twenty releases]({{ site.repo }}/releases), including two major rewrites with v2 and v3. With Bootstrap 2, we added responsive functionality to the entire framework as an optional stylesheet. Building on that with Bootstrap 3, we rewrote the library once more to make it responsive by default with a mobile first approach.
+Originally [released](https://blog.twitter.com/developer/en_us/a/2011/bootstrap-twitter.html) on <time datetime="2011-08-19 11:25">Friday, August 19, 2011</time>, we've since had over [twenty releases]({{ site.repo }}/releases), including two major rewrites with v2 and v3. With Bootstrap 2, we added responsive functionality to the entire framework as an optional stylesheet. Building on that with Bootstrap 3, we rewrote the library once more to make it responsive by default with a mobile first approach.
 
 With Bootstrap 4, we once again rewrote the project to account for two key architectural changes: a migration to Sass and the move to CSS's flexbox. Our intention is to help in a small way to move the web development community forward by pushing for newer CSS properties, fewer dependencies, and new technologies across more modern browsers.
 
diff --git a/docs/4.0/browser-bugs.md b/docs/4.0/browser-bugs.md
index d6d9115620..2340f90c29 100644
--- a/docs/4.0/browser-bugs.md
+++ b/docs/4.0/browser-bugs.md
@@ -10,7 +10,7 @@ We publicly list browser bugs that are impacting us here, in the hopes of expedi
 
 See also:
 
-* [Chromium issue 536263: [meta] Issues affecting Bootstrap](https://code.google.com/p/chromium/issues/detail?id=536263)
+* [Chromium issue 536263: [meta] Issues affecting Bootstrap](https://bugs.chromium.org/p/chromium/issues/detail?id=536263)
 * [Mozilla bug 1230801: Fix the issues that affect Bootstrap](https://bugzilla.mozilla.org/show_bug.cgi?id=1230801)
 * [WebKit bug 159753: [meta] Issues affecting Bootstrap](https://bugs.webkit.org/show_bug.cgi?id=159753)
 * [jQuery's browser bug workarounds](https://docs.google.com/document/d/1LPaPA30bLUB_publLIMF0RlhdnPx_ePXm7oW02iiT6o)
diff --git a/docs/4.0/components/dropdowns.md b/docs/4.0/components/dropdowns.md
index 417f816fb7..4ca2237841 100644
--- a/docs/4.0/components/dropdowns.md
+++ b/docs/4.0/components/dropdowns.md
@@ -16,7 +16,7 @@ If you're building our JavaScript from source, it [requires `util.js`]({{ site.b
 
 ## Accessibility
 
-The [<abbr title="Web Accessibility Initiative">WAI</abbr> <abbr title="Accessible Rich Internet Applications">ARIA</abbr>](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/TR/wai-aria/roles#menu), but this is specific to application-like menus which trigger actions or functions. <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus.
+The [<abbr title="Web Accessibility Initiative">WAI</abbr> <abbr title="Accessible Rich Internet Applications">ARIA</abbr>](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/WAI/PF/aria/roles#menu), but this is specific to application-like menus which trigger actions or functions. <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus.
 
 Bootstrap's dropdowns, on the other hand, are designed to be generic and applicable to a variety of situations and markup structures. For instance, it is possible to create dropdowns that contain additional inputs and form controls, such as search fields or login forms. For this reason, Bootstrap does not expect (nor automatically add) any of the `role` and `aria-` attributes required for true <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus. Authors will have to include these more specific attributes themselves.
 
diff --git a/docs/4.0/components/modal.md b/docs/4.0/components/modal.md
index d4be8783af..3ed09170e1 100644
--- a/docs/4.0/components/modal.md
+++ b/docs/4.0/components/modal.md
@@ -508,7 +508,7 @@ Modals have two optional sizes, available via modifier classes to be placed on a
     <div class="modal-content">
 
       <div class="modal-header">
-        <h4 class="modal-title" id="myLargeModalLabel">Large modal</h4>
+        <h5 class="modal-title h4" id="myLargeModalLabel">Large modal</h5>
         <button type="button" class="close" data-dismiss="modal" aria-label="Close">
           <span aria-hidden="true">&times;</span>
         </button>
@@ -524,7 +524,7 @@ Modals have two optional sizes, available via modifier classes to be placed on a
   <div class="modal-dialog modal-sm">
     <div class="modal-content">
       <div class="modal-header">
-        <h4 class="modal-title" id="mySmallModalLabel">Small modal</h4>
+        <h5 class="modal-title h4" id="mySmallModalLabel">Small modal</h5>
         <button type="button" class="close" data-dismiss="modal" aria-label="Close">
           <span aria-hidden="true">&times;</span>
         </button>
diff --git a/docs/4.0/components/navbar.md b/docs/4.0/components/navbar.md
index 7cb1d90251..d3b235c3e1 100644
--- a/docs/4.0/components/navbar.md
+++ b/docs/4.0/components/navbar.md
@@ -565,7 +565,7 @@ Sometimes you want to use the collapse plugin to trigger hidden content elsewher
 <div class="pos-f-t">
   <div class="collapse" id="navbarToggleExternalContent">
     <div class="bg-dark p-4">
-      <h4 class="text-white">Collapsed content</h4>
+      <h5 class="text-white h4">Collapsed content</h5>
       <span class="text-muted">Toggleable via the navbar brand.</span>
     </div>
   </div>
diff --git a/docs/4.0/examples/navbars/index.html b/docs/4.0/examples/navbars/index.html
index 95aaa92c2c..eb43971872 100644
--- a/docs/4.0/examples/navbars/index.html
+++ b/docs/4.0/examples/navbars/index.html
@@ -326,7 +326,7 @@
         <div class="jumbotron">
           <div class="col-sm-8 mx-auto">
             <h1>Navbar examples</h1>
-            <p>This example is a quick exercise to illustrate how the navbar and its contents work. Some navbars extend the width of the viewport, others are confined within a <code>.container</code>. For positioning of navbars, checkout the <a href="../navbar-top/">top</a> and <a href="../navbar-top-fixed/">fixed top</a> examples.</p>
+            <p>This example is a quick exercise to illustrate how the navbar and its contents work. Some navbars extend the width of the viewport, others are confined within a <code>.container</code>. For positioning of navbars, checkout the <a href="../navbar-static/">top</a> and <a href="../navbar-fixed/">fixed top</a> examples.</p>
             <p>At the smallest breakpoint, the collapse plugin is used to hide the links and show a menu button to toggle the collapsed content.</p>
             <p>
               <a class="btn btn-primary" href="../../components/navbar/" role="button">View navbar docs &raquo;</a>
diff --git a/docs/4.0/getting-started/browsers-devices.md b/docs/4.0/getting-started/browsers-devices.md
index e23de81977..8a4b0c8d73 100644
--- a/docs/4.0/getting-started/browsers-devices.md
+++ b/docs/4.0/getting-started/browsers-devices.md
@@ -112,7 +112,7 @@ Similarly, the latest versions of most desktop browsers are supported.
   </tbody>
 </table>
 
-For Firefox, in addition to the latest normal stable release, we also support the latest [Extended Support Release (ESR)](https://www.mozilla.org/en-US/firefox/organizations/faq/) version of Firefox.
+For Firefox, in addition to the latest normal stable release, we also support the latest [Extended Support Release (ESR)](https://www.mozilla.org/en-US/firefox/organizations/#faq) version of Firefox.
 
 Unofficially, Bootstrap should look and behave well enough in Chromium and Chrome for Linux, Firefox for Linux, and Internet Explorer 9, though they are not officially supported.
 
diff --git a/docs/4.0/getting-started/download.md b/docs/4.0/getting-started/download.md
index d9dbd5777b..e0845564cb 100644
--- a/docs/4.0/getting-started/download.md
+++ b/docs/4.0/getting-started/download.md
@@ -10,7 +10,7 @@ toc: true
 
 Download ready-to-use compiled code for **Bootstrap v{{ site.current_version}}** to easily drop into your project, which includes:
 
-- Compiled and minified CSS bundles (see [CSS files comparison]({{ site.baseurl }}/docs/{{ site.docs_version }}/getting-started/contents/#comparison-of-css-files))
+- Compiled and minified CSS bundles (see [CSS files comparison]({{ site.baseurl }}/docs/{{ site.docs_version }}/getting-started/contents/#css-files))
 - Compiled and minified JavaScript plugins
 
 This doesn't include documentation, source files, or any optional JavaScript dependencies (jQuery and Popper.js).
diff --git a/docs/4.0/layout/grid.md b/docs/4.0/layout/grid.md
index c8dad9ecf2..5d341b68a1 100644
--- a/docs/4.0/layout/grid.md
+++ b/docs/4.0/layout/grid.md
@@ -8,7 +8,7 @@ toc: true
 
 ## How it works
 
-Bootstrap's grid system uses a series of containers, rows, and columns to layout and align content. It's built with [flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Flexible_Box_Layout/Using_CSS_flexible_boxes) and is fully responsive. Below is an example and an in-depth look at how the grid comes together.
+Bootstrap's grid system uses a series of containers, rows, and columns to layout and align content. It's built with [flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Flexible_Box_Layout/Basic_Concepts_of_Flexbox) and is fully responsive. Below is an example and an in-depth look at how the grid comes together.
 
 **New to or unfamiliar with flexbox?** [Read this CSS Tricks flexbox guide](https://css-tricks.com/snippets/css/a-guide-to-flexbox/#flexbox-background) for background, terminology, guidelines, and code snippets.
 
@@ -46,7 +46,7 @@ Breaking it down, here's how it works:
 - Grid breakpoints are based on minimum width media queries, meaning **they apply to that one breakpoint and all those above it** (e.g., `.col-sm-4` applies to small, medium, large, and extra large devices, but not the first `xs` breakpoint).
 - You can use predefined grid classes (like `.col-4`) or [Sass mixins](#sass-mixins) for more semantic markup.
 
-Be aware of the limitations and [bugs around flexbox](https://github.com/philipwalton/flexbugs), like the [inability to use some HTML elements as flex containers](https://github.com/philipwalton/flexbugs#9-some-html-elements-cant-be-flex-containers).
+Be aware of the limitations and [bugs around flexbox](https://github.com/philipwalton/flexbugs), like the [inability to use some HTML elements as flex containers](https://github.com/philipwalton/flexbugs#flexbug-9).
 
 ## Grid options
 
@@ -151,7 +151,7 @@ For example, here are two grid layouts that apply to every device and viewport,
 {% include example.html content=example %}
 </div>
 
-Equal-width columns can be broken into multiple lines, but there was a [Safari flexbox bug](https://github.com/philipwalton/flexbugs#11-min-and-max-size-declarations-are-ignored-when-wrapping-flex-items) that prevented this from working without an explicit `flex-basis` or `border`. There are workarounds for older browser versions, but they shouldn't be necessary if you're up-to-date.
+Equal-width columns can be broken into multiple lines, but there was a [Safari flexbox bug](https://github.com/philipwalton/flexbugs#flexbug-11) that prevented this from working without an explicit `flex-basis` or `border`. There are workarounds for older browser versions, but they shouldn't be necessary if you're up-to-date.
 
 <div class="bd-example-row">
 {% capture example %}
diff --git a/docs/4.0/layout/media-object.md b/docs/4.0/layout/media-object.md
index 70a5e6a942..500fa3e315 100644
--- a/docs/4.0/layout/media-object.md
+++ b/docs/4.0/layout/media-object.md
@@ -28,7 +28,7 @@ Below is an example of a single media object. Only two classes are required—th
 
 Internet Explorer 10-11 do not render inline elements like links or images (or `::before` and `::after` pseudo-elements) as flex items. The only workaround is to set a non-inline `display` value (e.g., `block`, `inline-block`, or `flex`). We suggest using `.d-flex`, one of our [display utilities]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/display/), as an easy fix.
 
-**Source:** [Flexbugs on GitHub](https://github.com/philipwalton/flexbugs#12-inline-elements-are-not-treated-as-flex-items)
+**Source:** [Flexbugs on GitHub](https://github.com/philipwalton/flexbugs#flexbug-12)
 {% endcapture %}
 {% include callout.html content=callout type="warning" %}