How to horizontally center Bootstrap 3 row? - html

Question

I created a 'mega menu' with Bootstrap 3.
I'm having trouble getting the row that creates the mega-menu horizontally centered and retaining functionality. Element in question has class .mega-dropdown-menu.
<ul class="dropdown-menu mega-dropdown-menu row">
Here's the code snippet pertaining to my issue :
body {
background: #f0f0f0;
}
.dropdown-menu {
background-color: #f5f5f5;
}
.navbar-header {
background-color: #3a7dbb;
}
.collapse.navbar-collapse.js-navbar-collapse {
background-color: #3a7dbb;
/* ?=border-bottom: 5px solid #214f82 */
}
.navbar-default .navbar-nav > li > a.dropdown-toggle {
font-size: 16px;
color: white;
}
.dropdown > .dropdown-menu > li > a {
font-size: 16px;
}
.glyphicon-shopping-cart:before {
color: white;
}
.navbar .navbar-brand {
padding-top: 0px;
}
.dropdown > .dropdown-menu > li > a:hover {
background-color: white;
}
.navbar-nav > li > .dropdown-menu {
background-color: #f5f5f5;
margin-top: 20px;
border-top-left-radius: 4px;
border-top-right-radius: 4px;
}
.navbar-default .navbar-nav > li > a {
/* width: 8em; */
font-weight: bold;
}
.mega-dropdown {
position: static !important;
width: 100%;
}
.mega-dropdown-menu {
padding: 20px 0px;
width: 100%;
box-shadow: none;
-webkit-box-shadow: none;
}
.center {
margin: auto;
}
.mega-dropdown-menu > li > ul {
padding: 0;
margin: 0;
}
.mega-dropdown-menu > li > ul > li {
list-style: none;
}
.mega-dropdown-menu > li > ul > li > a {
display: block;
padding: 3px 20px;
clear: both;
font-weight: normal;
line-height: 1.428571429;
color: #262626;
white-space: normal;
}
.i-am-centered {
margin: auto;
max-width: 300px;
}
.mega-dropdown-menu > li ul > li > a {
font-size: 16px;
}
.mega-dropdown-menu > li ul > li > a:hover,
.mega-dropdown-menu > li ul > li > a:focus {
text-decoration: none;
color: #444;
background-color: white;
}
li.dropdown:hover {
background-color: #c3c1c1;
}
ul.dropdown-menu.mega-dropdown-menu.row {
width: 80%;
}
.mega-dropdown-menu .dropdown-header {
color: #428bca;
font-size: 18px;
font-weight: bold;
}
.mega-dropdown-menu .dropdown-header > a {
color: #428bca;
font-size: 18px;
font-weight: bold;
padding-left: 0;
}
.mega-dropdown-menu form {
margin: 3px 20px;
}
.mega-dropdown-menu .form-group {
margin-bottom: 3px;
}
.navbar-default .navbar-nav .open .dropdown-menu > li > a {
color: black !important;
}
#media only screen and (min-width: 768px) {
.dropdown:hover > .dropdown-menu {
display: block;
}
.dropdown > .dropdown-toggle:active {
pointer-events: none;
}
}
/* .mega-dropdown-menu:before {
content: "";
border-bottom: 15px solid #fff;
border-right: 17px solid transparent;
border-left: 17px solid transparent;
position: absolute;
top: -15px;
left: 285px;
z-index: 10;
}
.mega-dropdown-menu:after {
content: "";
border-bottom: 17px solid #ccc;
border-right: 19px solid transparent;
border-left: 19px solid transparent;
position: absolute;
top: -17px;
left: 283px;
z-index: 8;
} */
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="">
<nav class="navbar navbar-default">
<div class="navbar-header">
<button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".js-navbar-collapse">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#"><img src="https://brm.institute/wp-content/themes/brmi/images/brm-institute-logo.png"></a>
</div>
<div class="collapse navbar-collapse js-navbar-collapse">
<ul class="nav navbar-nav">
<li class="dropdown mega-dropdown">
Dummy MegaMenu<span class="caret"></span>
<ul class="dropdown-menu mega-dropdown-menu row">
<li class="col-sm-4">
<ul>
<li class="dropdown-header">Dresses</li>
<li>Unique Features</li>
<li>Image Responsive</li>
<li>Auto Carousel</li>
<li>Newsletter Form</li>
<li>Four columns</li>
<li class="divider"></li>
<li class="dropdown-header">Tops</li>
<li>Good Typography</li>
</ul>
</li>
<li class="col-sm-4">
<ul>
<li class="dropdown-header">Jackets</li>
<li>Easy to customize</li>
<li>Glyphicons</li>
<li>Pull Right Elements</li>
<li class="divider"></li>
<li class="dropdown-header">Pants</li>
<li>Coloured Headers</li>
<li>Primary Buttons & Default</li>
<li>Calls to action</li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
<!-- /.nav-collapse -->
</nav>
</div>
Code available on codepen as well.
Any help would be appreciated,
Thank you

Answer 1

For your current problem, set .mega-dropdown-menu to either :
01 Using translate :
left: 50% /* instead of 0 */
transform: translateX(-50%);
02 Using margins (prefered solution IMO)
left: 0;
right: 0;
margin: 0 auto; /* Centers the element */

Answer 2

Not enough Rep to add a comment sorry.
I always found:
margin-right: auto;
margin-left: auto;
Does the trick without a need to set a left/right position.
You can also used the class "center-block" built in to Bootstrap 3 to apply this css as a class.
Personally I would recommend updating to Bootstrap 4, took me a while to make the leap but the flexgrid is such an improvement its worth it. Most of the classes are interchangeable to some degree, though in bootstrap 4 "center-block" is now "mx-auto"