Merge branch 'v4-dev' into v4-navbars

diff --cc docs/components/navbar.md
index a82f881a2160284fdaf77e565f9f178ab3c55d33,10f445e8f04077a238e3f76f08682b4ad4c10c80..bb390a55c4456639bf5841f65fd141c0f2a6b627
--- 1/docs/components/navbar.md
--- 2/docs/components/navbar.md
+++ b/docs/components/navbar.md
@@@ -304,25 -241,9 +304,23 @@@ Our collapse plugin allows you to use 
  
  {% example html %}
  <nav class="navbar navbar-light bg-faded">
-   <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#exCollapsingNavbar" aria-controls="exCollapsingNavbar" aria-expanded="false" aria-label="Toggle navigation">
-     &#9776;
-   </button>
+   <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#exCollapsingNavbar" aria-controls="exCollapsingNavbar" aria-expanded="false" aria-label="Toggle navigation"></button>
    <div class="collapse" id="exCollapsingNavbar">
 -    <div class="bg-inverse p-a-1">
 +    <div class="bg-inverse text-muted p-a-1">
 +      <h4>Collapsed content</h4>
 +      <span class="text-muted">Toggleable via the navbar brand.</span>
 +    </div>
 +  </div>
 +</nav>
 +{% endexample %}
 +
 +{% example html %}
 +<nav class="navbar navbar-dark bg-inverse">
 +  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#exCollapsingNavbarDark" aria-controls="exCollapsingNavbarDark" aria-expanded="false" aria-label="Toggle navigation">
 +    &#9776;
 +  </button>
 +  <div class="collapse" id="exCollapsingNavbarDark">
 +    <div class="bg-inverse text-muted p-a-1">
        <h4>Collapsed content</h4>
        <span class="text-muted">Toggleable via the navbar brand.</span>
      </div>

diff --cc scss/_navbar.scss
index 6e563d4390cc43950d3c41f9c0536dbf01c294ee,c91e830bdd043610d46684ea6d56417c48bfcba0..def526fdd1f758cb9b8a5c354b41a332304dbeba
--- 1/scss/_navbar.scss
--- 2/scss/_navbar.scss
+++ b/scss/_navbar.scss
@@@ -116,12 -105,15 +116,15 @@@
  // Bootstrap JavaScript plugin.
  
  .navbar-toggler {
 -  padding: .5rem .75rem;
 -  font-size: $font-size-lg;
+   width: 2.5em;
+   height: 2em;
 +  padding: $navbar-toggler-padding-y $navbar-toggler-padding-x;
 +  font-size: $navbar-toggler-font-size;
    line-height: 1;
-   background: none;
+   background: transparent no-repeat center center;
+   background-size: 24px 24px;
    border: $border-width solid transparent;
 -  @include border-radius($btn-border-radius);
 +  @include border-radius($navbar-toggler-border-radius);
  
    @include hover-focus {
      text-decoration: none;

diff --cc scss/_variables.scss
Simple merge