This question is less of a code question and more of a best-practices question. I am working on a custom bootstrap theme based on https://github.com/HackerThemes/theme-kit. I have a working theme that I like, however, I am overriding some styles in the original Bootstrap theme. Even in the minified CSS, these are duplicated. For example, Bootstrap defines...
.btn-danger:hover {
color: #fff;
background-color: #ae130b;
border-color: #a2120a;
}
...but my code also defines...
.btn-danger:hover {
border-color: #0000;
}
In the final stylesheet, both of these styles are present. The second style overrides Bootstrap and it looks just fine. However, this leads to useless code. First of all, is there a postprocessor of some sort that I can use with Gulp to eliminate these duplicates and consolidate them? Second, should I just fork the Bootstrap repository and modify the original SCSS directly?
It depends on what you #import. Looking at mytheme.scss, the entire Bootstrap SASS is imported, creating full duplicate code in the final CSS.
Instead you can pick specific SASS files to import and look at the option variables which also effects what CSS is generated. For example, setting $enable-grid-classes: false will prevent duplication of the entire grid system in the generated CSS.
I know I can just have a custom stylesheet that overrides the bootstrap component I wish to customize (for example the jumbotron), but is the right way to go about this "problem"? I don't think this can be done with a bootstrap theme, although I haven't read a whole lot on this subject.
You can use your browsers DevTools to inspect an element that you want to change, and in the Rules/Styles section you can see which CSS elements is it using and then you can create your own css file and paste the CSS there and change it so it overrides bootstraps element. Here is how to get the devtools from Chrome https://developer.chrome.com/devtools#dom-and-styles and from Firefox https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Open_the_Inspector. Don't forget to import your CSS customised script under bootstraps so it overrides the CSS that you wish to change.
Use twitter-bootstrap customize on their website to customize it and download the customized files. Or just create a custom CSS file and edit classes like .jumbotron and other stuff
There are a few ways to modify the default bootstrap css and no one way is inherently more or less "right" than any other. It all depends on the coding style of you and/or your team. Here is a list of a few ways that I came up with off the top of my head:
Modify the css file you downloaded from Bootstrap
(My Choice) Override Bootstrap styles with your own CSS. Just be sure to follow the rules of CSS Specificity (External < Internal < Inline) and if you have trouble getting a certain rule to apply try reading this answer or force it with !important
NOTE: This is likely NOT a comprehensive list, just a starting point.
Zurb Foundation's text field have a 1em bottom margin that I want to remove.
I couldn't find custom scss in zurb foundation documents.
I'm overwriting the stylesheet by using !important option.
But if possible I don't want to use it.
Is there better way to remove the margin from foundation form text field?
I'm using foundation in a rails project.
You can override the styles without using !important option.
If there are multiple contradictory CSS file then whichever gets called LAST will override the previous one.
For example if you add below styles in your CSS file and include it after docs.css then it gets highest priority.
Have a look at the JS Fiddle
input[type="text"]{
margin: 0;
}
If you want to use the SCSS method you want to change the value for $form-spacing;
Forms | Foundation for Sites 6 docs
$form-spacing: rem-calc(16);
In a Rails app I am using Twitter Bootstrap as a starting point. Twitter Bootstrap uses some of the HTML5 Boilerplate reset which includes this gem:
#media print {
* {
color: #000 !important; /* Black prints faster: h5bp.com/s */
}
}
(note the linked article is from 200-effing-8)
My app outputs PDF using pdfkit/wkhtmltopdf and due to the above declaration all pdf output is black on white. The whole point of pdfkit/wkhtmltopdf (to me, in this app) is for PDF output to match the screen.
Is there any way for me to override this declaration in my stylesheets after Bootstrap is imported? I want it to be something along the lines of "auto" but that doesn't appear to be valid.
I can, of course, comment out the line in Bootstrap, but I'd rather avoid changing the source if I can (since I'm bringing it all in via the bootstrap-sass gem). I could also tell pdfkit/wkhtmltopdf to not use "print" stylesheets, but that creates different problems.
I've tried setting it to "inherit" but functionally that isn't what I'm after, and it doesn't seem to work anyway.
Thanks.
I would comment it out in the bootstrap css. The asterisk selector is a wildcard which will set all text content to black. Otherwise you would have to write out a lot of individual CSS rules using id or class to override. If most of the text content on your site is already set to black or a dark enough color, then you don't need that CSS print rule.
I am just getting started with Bootstrap from Twitter and am wondering what the ‘best practices’ is for customization. I want to develop a system that will take advantage of all the power of a css template (Bootstrap or other), be completely (and easily) modifiable, be sustainable (ie – when the next version of Bootstrap is released from Twitter I don’t have to start over.
For example, I want to add background images to the top navigation. It looks like there are 3 ways to go about this:
Modify the .topbar classes in bootstrap.css . I don’t particularly like this because I will have lots of .topbar items and I don’t necessarily want to modify them all the same way.
Create new classes with my background images and apply both styles (the new and the bootstrap to my element). This may create style conflicts, which could be avoided by stripping the .topbar class into separate classes and then only using the pieces that are not stepped on by my custom class. Again this requires more work than I think should be necessary and while it is flexible, it won’t allow me to easily update bootstrap.css when Twitter releases the next installment.
Use variables in .LESS to achieve the customization. Offhand this seems like a good approach but having not used .LESS I have concerns about compiling css on the client and about code sustainability.
Though I am using Bootstrap, this question can be generalized to any css template.
The best thing to do is.
1. fork twitter-bootstrap from github and clone locally.
they are changing really quickly the library/framework (they diverge internally. Some prefer library, i'd say that it's a framework, because change your layout from the time you load it on your page). Well... forking/cloning will let you fetch the new upcoming versions easily.
2. Do not modify the bootstrap.css file
It's gonna complicate your life when you need to upgrade bootstrap (and you will need to do it).
3. Create your own css file and overwrite whenever you want original bootstrap stuff
if they set a topbar with, let's say, color: black; but you wan it white, create a new very specific selector for this topbar and use this rule on the specific topbar. For a table for example, it would be <table class="zebra-striped mycustomclass">. If you declare your css file after bootstrap.css, this will overwrite whatever you want to.
Bootstrap 5 (update 2021)
As explained in the Bootstrap docs, modifying the existing "theme" colors is done using SASS. As with prior versions, you can also override the Bootstrap CSS by adding CSS rules that follow after the bootstrap.css and use the correct CSS specificity.
Bootstrap 5 - change theme colors
Bootstrap 4
I'm revisiting this Bootstrap customization question for 4.x, which now utilizes SASS instead of LESS. In general, there are 2 ways to customize Bootstrap...
1. Simple CSS Overrides
One way to customize is simply using CSS to override Bootstrap CSS. For maintainability, CSS customizations are put in a separate custom.css file, so that the bootstrap.css remains unmodified. The reference to the custom.css follows after the bootstrap.css for the overrides to work...
<link rel="stylesheet" type="text/css" href="css/bootstrap.min.css">
<link rel="stylesheet" type="text/css" href="css/custom.css">
Just add whatever changes are needed in the custom CSS. For example...
/* remove rounding from cards, buttons and inputs */
.card, .btn, .form-control {
border-radius: 0;
}
Before (bootstrap.css)
After (with custom.css)
When making customizations, you should understand CSS Specificity. Overrides in the custom.css need to use selectors that are the same specificity as (or more specific) the bootstrap.css.
Note there is no need to use !important in the custom CSS, unless
you're overriding one of the Bootstrap Utility
classes. CSS
specificity
always works for one CSS class to override another.
2. Customize using SASS
If you're familiar with SASS (and you should be to use this method), you can customize Bootstrap with your own custom.scss. There is a section in the Bootstrap docs that explains this, however the docs don't explain how to utilize existing variables in your custom.scss. For example, let's change the body background-color to #eeeeee, and change/override the blue primary contextual color to Bootstrap's $purple variable...
/* custom.scss */
/* import the necessary Bootstrap files */
#import "bootstrap/functions";
#import "bootstrap/variables";
/* -------begin customization-------- */
/* simply assign the value */
$body-bg: #eeeeee;
/* use a variable to override primary */
$theme-colors: (
primary: $purple
);
/* -------end customization-------- */
/* finally, import Bootstrap to set the changes! */
#import "bootstrap";
This also works to create new custom classes. For example, here I add purple to the theme colors which creates all the CSS for btn-purple, text-purple, bg-purple, alert-purple, etc...
/* add a new purple custom color */
$theme-colors: (
purple: $purple
);
https://codeply.com/go/7XonykXFvP
With SASS you must #import bootstrap after the customizations to make them work! Once the SASS is compiled to CSS (this must be done using a SASS compiler node-sass, gulp-sass, npm webpack, etc..), the resulting CSS is the customized Bootstrap. If you're not familiar with SASS, you can customize Bootstrap using a tool like this theme builder I created.
Custom Bootstrap Demo (SASS)
Note: Unlike 3.x, Bootstrap 4.x doesn't offer an official customizer tool. You can however, download the grid only CSS or use another 4.x custom build tool to re-build the Bootstrap 4 CSS as desired.
Related:
How to extend/modify (customize) Bootstrap 4 with SASS
How to change the bootstrap primary color?
How to create new set of color styles in Bootstrap 4 with sass
How to Customize Bootstrap
I think the officially preferred way is now to use Less, and either dynamically override the bootstrap.css (using less.js), or recompile bootstrap.css (using Node or the Less compiler).
From the Bootstrap docs, here's how to override bootstrap.css styles dynamically:
Download the latest Less.js and include the path to it (and Bootstrap) in the <head>.
<link rel="stylesheet/less" href="/path/to/bootstrap.less">
<script src="/path/to/less.js"></script>
To recompile the .less files, just save them and reload your page. Less.js compiles them and stores them in local storage.
Or if you prefer to statically compile a new bootstrap.css with your custom styles (for production environments):
Install the LESS command line tool via Node and run the following command:
$ lessc ./less/bootstrap.less > bootstrap.css
Since Pabluez's answer back in December, there is now a better way to customize Bootstrap.
Use: Bootswatch to generate your bootstrap.css
Bootswatch builds the normal Twitter Bootstrap from the latest version (whatever you install in the bootstrap directory), but also imports your customizations. This makes it easy to use the the latest version of Bootstrap, while maintaining custom CSS, without having to change anything about your HTML. You can simply sway boostrap.css files.
You can use the bootstrap template from
http://www.initializr.com/
which includes all the bootstrap .less files. You can then change variables / update the less files as you want and it will automatically compile the css. When deploying compile the less file to css.
The best option in my opinion is to compile a custom LESS file including bootstrap.less, a custom variables.less file and your own rules :
Clone bootstrap in your root folder : git clone https://github.com/twbs/bootstrap.git
Rename it "bootstrap"
Create a package.json file : https://gist.github.com/jide/8440609
Create a Gruntfile.js : https://gist.github.com/jide/8440502
Create a "less" folder
Copy bootstrap/less/variables.less into the "less" folder
Change the font path : #icon-font-path: "../bootstrap/fonts/";
Create a custom style.less file in the "less" folder which imports bootstrap.less and your custom variables.less file : https://gist.github.com/jide/8440619
Run npm install
Run grunt watch
Now you can modify the variables any way you want, override bootstrap rules in your custom style.less file, and if some day you want to update bootstrap, you can replace the whole bootstrap folder !
EDIT: I created a Bootstrap boilerplate using this technique : https://github.com/jide/bootstrap-boilerplate
I recently wrote a post about how I've been doing it at Udacity for the last couple years. This method has meant we've been able to update Bootstrap whenever we wanted to without having merge conflicts, thrown out work, etc. etc.
The post goes more in depth with examples, but the basic idea is:
Keep a pristine copy of bootstrap and overwrite it externally.
Modify one file (bootstrap's variables.less) to include your own variables.
Make your site file #include bootstrap.less and then your overrides.
This does mean using LESS, and compiling it down to CSS before shipping it to the client (client-side LESS if finicky, and I generally avoid it) but it is EXTREMELY good for maintainability/upgradability, and getting LESS compilation is really really easy. The linked github code has an example using grunt, but there are many ways to achieve this -- even GUIs if that's your thing.
Using this solution, your example problem would look like:
Change the nav bar color with #navbar-inverse-bg in your variables.less (not bootstrap's)
Add your own nav bar styles to your bootstrap_overrides.less, overwriting anything you need to as you go.
Happiness.
When it comes time to upgrade your bootstrap, you just swap out the pristine bootstrap copy and everything will still work (if bootstrap makes breaking changes, you'll need to update your overrides, but you'd have to do that anyway)
Blog post with walk-through is here.
Code example on github is here.
Use LESS with Bootstrap...
Here are the Bootstrap docs for how to use LESS
(they have moved since previous answers)
you can start with this tool, https://themestr.app/theme , seeing how it overwrites the scss variables, you would get an idea what variable impacts what. its the simplest way I think.
example scss genearation:
#import url(https://fonts.googleapis.com/css?family=Montserrat:200,300,400,700);
$font-family-base:Montserrat;
#import url(https://fonts.googleapis.com/css?family=Open+Sans:200,300,400,700);
$headings-font-family:Open Sans;
$enable-grid-classes:false;
$primary:#222222;
$secondary:#666666;
$success:#333333;
$danger:#434343;
$info:#515151;
$warning:#5f5f5f;
$light:#eceeec;
$dark:#111111;
#import "bootstrap";