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How can I overwrite the stylings in Twitter Bootstrap? For instance, I am currently using a .sidebar class that has the CSS rule 'float: left;' How can I change this so that it goes to the right instead? I'm using HAML and SASS but am relatively new to web development.

GEOCHET
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John
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8 Answers8

233

All these tips will work, but a simpler way might be to include your stylesheet after the Bootstrap styles.

If you include your css (site-specific.css) after Bootstrap's (bootstrap.css), you can override rules by redefining them.

For example, if this is how you include CSS in your <head>

<link rel="stylesheet" href="css/bootstrap.css" />
<link rel="stylesheet" href="css/site-specific.css" />

You can simply move the sidebar to the right by writing (in your site-specific.css file):

.sidebar {
    float: right;
}

Forgive the lack of HAML and SASS, I do not know them well enough to write tutorials in them.

pingswept
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citelao
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  • What about the "-responsive.css" styles? Can those be overwritten in the same way? – Claudiu Constantin Nov 18 '12 at 10:24
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    @ClaudiuConstantin I see no reason why not. The rule of thumb is the second style will *always* trump the first if two are the same level of specificity. As long as your style comes after it will override. – citelao Nov 19 '12 at 22:27
  • I load my style after the bootstrap's css files, but I can't override any elements unless I force it with "!important". – Kreker Apr 19 '13 at 07:46
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    @Kreker That probably has a lot to do with specificity. You can read up about it [here](http://coding.smashingmagazine.com/2007/07/27/css-specificity-things-you-should-know/) (old article), but basically `.sidebar.right` is more specific than `.sidebar`. That is probably the problem. Use web inspector to figure out what's overriding it. – citelao Apr 21 '13 at 00:55
  • @citelao I'm trying to override `.brand` class of the navbar. So `.brand{}` works only with `!important` instead `div.container > a.brand{}` override correctly without `!important`, it's the right way to do? – Kreker Apr 22 '13 at 10:14
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    @Kreker yup, that's the idea. The problem with `!important` is that you can never override it again in the future. – citelao Apr 23 '13 at 12:11
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    My `Site.css` is bundled up and listed in `Bundle.config` and rendered physically *after* `bootstrap.css` but the styles are still not overridden. I had to take the `site.css` reference out of the modernizer bundle and manually put that after the `bootstrap.css` (and press Ctrl + F5 once debugging to clear the cache) – atconway Sep 18 '13 at 18:17
  • By far the easiest solution! Thanks a bunch! +1 – Jeel Shah Nov 11 '14 at 23:18
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    This might work but it wouldn't be best practice for production. Load 1 stylesheet per site unless there's a big reason not to. #sitespeed – Ben Racicot Apr 23 '15 at 20:31
  • @BenRacicot You should minify your stylesheets for production anyway. The advice is really just "include your more specific styles AFTER Bootstrap." See also [this question](http://stackoverflow.com/questions/2336302/single-huge-css-file-vs-multiple-smaller-specific-css-files) – citelao Apr 23 '15 at 23:10
  • This won't work in many cases. CSS rules aren't prioritized based on what comes last, but on specificity levels. See https://stackoverflow.com/questions/20721248/best-way-to-override-bootstrap-css or the answer below. – Błażej Michalik Jun 19 '16 at 22:09
  • @BłażejMichalik You are only partially correct. They are prioritized by both order and specificity. See item 4 of [6.4.1 Cascading Order](https://www.w3.org/TR/2011/REC-CSS2-20110607/cascade.html#cascade). Most modern CSS design principles suggest that [high specificity is bad](http://csswizardry.com/2012/05/keep-your-css-selectors-short/). But, yes, sometimes Bootstrap has high specificity and you will need to be equally specific. I still think my answer is better than the accepted one, though. – citelao Jun 21 '16 at 02:18
  • @citelao It says that the "order of ordering" is: importance -> specificity -> inclusion order. I'm pretty sure that in most cases it would be quite hard to step on the same specificity that bootstrap uses. – Błażej Michalik Jun 21 '16 at 17:28
  • @BłażejMichalik I still argue that inclusion order is your most "idiomatic" way to override (i.e. if possible, prefer that). For this specific question, that is possible. For other questions, you are, of course, correct. No inclusion order beats specificity. – citelao Jun 27 '16 at 04:44
58

The answer to this is CSS Specificity. You need to be more "specific" in your CSS so that it can override bootstrap css properties.

For example you have a sample code for a bootstrap menu here:

<nav class="navbar navbar-inverse navbar-fixed-top" role="navigation">
    <div id="home-menu-container" class="collapse navbar-collapse">
        <ul id="home-menu" class="nav navbar-nav">
            <li><a class="navbar-brand" href="#"><img src="images/xd_logo.png" /></a></li>
            <li><a href="#intro">Home</a></li>
            <li><a href="#about">About Us</a></li>
            <li><a href="#services">What We Do</a></li>
            <li><a href="#process">Our Process</a><br /></li>
            <li><a href="#portfolio">Portfolio</a></li>
            <li><a href="#contact">Contact Us</a></li>
        </ul>
    </div><!-- /.navbar-collapse -->
</nav>

Here, you need to remember the hierarchy of the specificity. It goes like this:

  • Give an element with an id mentioned 100 points
  • Give an element with a class mentioned 10 points
  • Give a simple element a single 1 point

So, for the above if your css has something like this:

.navbar ul li a { color: red; } /* 10(.navbar) + 1(ul) + 1(li) + 1(a) = 13 points */
.navbar a { color: green; } /* 10(.navbar) + 1(a) = 11 points */

So, even if you have defined the .navbar a after .navbar ul li a it is still going to override with a red colour, instead of a green since the specificity is more (13 points).

So, basically all you need to do is calculate the points for the element you are wanting to change the css for, via inspect element on your browser. Here, bootstrap has specified its css for the element as

.navbar-inverse .navbar-nav>li>a { /* Total = 22 points */
    color: #999;
}

So, even if your css is loading is being loaded after bootstrap.css which has the following line:

.navbar-nav li a {
    color: red;
}

it's still going to be rendered as #999. In order to solve this, bootstrap has 22 points (calculate it yourself). So all we need is something more than that. Thus, I have added custom IDs to the elements i.e. home-menu-container and home-menu. Now the following css will work:

#home-menu-container #home-menu li a { color: red; } /* 100 + 100 + 1 + 1 = 202 points :) */

Done.

You can refer to this MDN link.

kaizer1v
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    What if they're tied? – Confused May 23 '15 at 20:34
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    It doesn't matter, for example '.abc.xyz' means, there is an element with class 'abc' and 'xyz' - it will still take it as a single element with a class. Thus, 10 points. same goes for an ID. – kaizer1v May 25 '15 at 15:53
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    Well written! Thank you! – GobSmack Jul 23 '15 at 14:42
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    This was the trick for me. I was having trouble over-riding the `blockquote` style in the Bootstrap CSS. Strangely, it was wrong for normal blockquotes but looked right for and
      within a blockquote. The key was updating my CSS to have `blockquote p`, which gave enough priority. The
        was doing this for the other section of the page.
     – Adam Wuerl Feb 09 '16 at 03:09
41

Add your own class, ex: <div class="sidebar right"></div>, with the CSS as

.sidebar.right { 
    float:right
}
Damon Bauer
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20

You can overwrite a CSS class by making it "more specific".

You go up the HTML tree, and specify parent elements:

div.sidebar { ... } is more specific than .sidebar { ... }

You can go all the way up to BODY if you need to:

body .sidebar { ... } will override virtually anything.

See this handy guide: http://css-tricks.com/855-specifics-on-css-specificity/

Diodeus - James MacFarlane
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9

You can just make sure your css file parses AFTER boostrap.css , like so:

<link href="css/bootstrap.css" rel="stylesheet">
<link href="css/myFile.css" rel="stylesheet">

Peter Girnus
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6

If you want to overwrite any css in bootstrap use !important

Let's say here is the page header class in bootstrap which have 40px margin on top, my client don't like it and he want it to be 15 on top and 10 on bottom only

.page-header {
    border-bottom: 1px solid #EEEEEE;
    margin: 40px 0 20px;
    padding-bottom: 9px;
}

So I added on class in my site.css file with the same name like this

.page-header
{
    padding-bottom: 9px;
    margin: 15px 0 10px 0px !important;
}

Note the !important with my margin, which will overwrite the margin of bootstarp page-header class margin.

Ali Adravi
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    Note that using !important is somewhat of an anti-pattern. Read more here: http://james.padolsey.com/css/dont-use-important/ – mayatron Aug 13 '15 at 03:40
3

Came across this late, but I think it could use another answer.

If you're using sass, you can actually change the variables before you import bootstrap. http://twitter.github.com/bootstrap/customize.html#variables

Change any of them, such as:

$bodyBackground: red;
@import "bootstrap";

Alternatively if there isn't a variable available for what you want to change, you can override the styles or add your own.

Sass:

@import "bootstrap";

/* override anything manually, like rounded buttons */
.btn {
  border-radius: 0;
}

Also see this: Proper SCSS Asset Structure in Rails

Community
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AJcodez
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2

I know this is an old question but still, I came across a similar problem and i realized that my "not working" css code in my bootstrapOverload.css file was written after the media queries. when I moved it above media queries it started working.

Just in case someone else is facing the same problem

md1hunox
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