The main.css file from HTML5 Boilerplate
npm install main.cssA repository for the development of the HTML5 Boilerplate CSS file, style.css.
Historically, the file shipped with HTML5 Boilerplate was called main.css, hence the name of this project. It's since been renamed to style.css. Just in case you were confused.
This project includes both the whole main.css file as well as component files used to generate main.css. This way you can either pull in the whole file, as we do in HTML5 Boilerplate (renaming it to style.css) or you can pull in the individual files as needed.

Choose one of the following options:
- Download as part of the latest stable release of HTML5 Boilerplate from
html5boilerplate.com.
- Clone the git repo — git clone - and checkout the
https://github.com/h5bp/main.css.git
tagged release
you'd like to use.
- Install with npm: npm install main.css and pull in what you need from the resulting node_modules/main.css/distfolder
- Install with yarn: yarn add main.css and pull in what you need from the resulting node_modules/main.css/distfolder
The project contains the following files, which combine to create the different sections of main.css.
Several base styles are included. These styles:
- provide basic typography settings that improve text readability
- protect against unwanted text-shadow during text highlighting
- tweak the default alignment of some elements (e.g.: img, video,
fieldset, textarea)
Along with the base styles, we also provide some commonly used helper classes.
#### .hidden
The hidden class can be added to any element that you want to hide visually
and from screen readers. It could be an element that will be populated and
displayed later, or an element you will hide with JavaScript.
#### .visually-hidden
The visually-hidden class can be added to any element that you want to hide
visually, while still have its content accessible to screen readers.
#### .invisible
The invisible class can be added to any element that you want to hide
visually and from screen readers, but without affecting the layout.
As opposed to the hidden class that effectively removes the element from the
layout, the invisible class will simply make the element invisible while
keeping it in the flow and not affecting the positioning of the surrounding
content.
#### .clearfix
The clearfix class can be added to any element to ensure that it always fully
contains its floated children.
Over the years there have been many variants of the clearfix hack, but currently, we use the micro clearfix.
We include placeholder media queries to help you build up your mobile styles for
wider viewports and high-resolution displays. It's recommended that you adapt
these media queries based on the content of your site rather than mirroring the
fixed dimensions of specific devices.
If you do not want to take the _mobile first_ approach, you can simply edit or
remove these placeholder media queries. One possibility would be to work from
wide viewports down, and use max-width media queries instead (e.g.:@media only screen and (max-width: 480px)).
Lastly, we provide some useful print styles that will optimize the printing
process, as well as make the printed pages easier to read.
At printing time, these styles will:
- strip all background colors, change the font color to black, and remove the
text-shadow — done in order to help save printer ink and speed up the
printing process
- underline and expand links to include the URL — done in order to allow users
to know where to refer to
(exceptions to this are: the links that are
fragment identifiers,
or use the
javascript: pseudo protocol)
- expand abbreviations to include the full description — done in order to allow
users to know what the abbreviations stands for
- provide instructions on how browsers should break the content into pages and
on orphans/widows, namely,
we instruct
supporting browsers
that they should:
- prevent block quotations, preformatted text, images and table rows from
being split onto two different pages
- ensure that headings never appear on a different page than the text they
are associated with
- ensure that
orphans and widows do
not appear on printed pages
The print styles are included along with the other css to avoid the
additional HTTP request.
Also, they should always be included last, so that the other styles can be
overwritten.
We use the following browserlist configuration:
````
" browserslist": [
"> 0.5%",
"last 2 versions",
"Firefox ESR",
"not dead",
"IE 11"
],
That configuration translates to this full list of browsers.
Anyone is welcome to contribute,
however, if you decide to get involved, please take a moment to review
the guidelines:
- Bug reports
- Feature requests
- Pull requests
The code is available under the MIT license.