HTML5 Boilerplate homepage | Documentation table of contents

The CSS

The HTML5 Boilerplate starting CSS includes:

• Normalize.css.
• Useful HTML5 Boilerplate defaults.
• Common helpers.
• Placeholder media queries.
• Print styles.

This starting CSS does not rely on the presence of conditional classnames, conditional style sheets, or Modernizr. It is ready to use whatever your development preferences happen to be.

Normalize.css

Normalize.css is a modern, HTML5-ready alternative to CSS resets. It contains extensive inline documentation. Please refer to the Normalize.css project for more information.

HTML5 Boilerplate defaults

This project includes a handful of base styles that build upon Normalize.css. These include:

• Basic typography settings to provide improved text readability by default.
• Protection against unwanted text-shadow during text highlighting.
• Tweaks to default image alignment, fieldsets, and textareas.
• A pretty prompt to update your browser if you are on an outdated browser.

You are free to modify or add to these base styles as your project requires.

Common helpers

.ir

Add the .ir class to any element you are applying image-replacement to. When replacing an element's content with an image, make sure to also set a specific background-image: url(pathtoimage.png);, width, and height so that your replacement image appears.

.hidden

Add the .hidden class to any elements that you want to hide from all presentations, including screen readers. It could be an element that will be populated later with JavaScript or an element you will hide with JavaScript. Do not use this for SEO keyword stuffing. That is just not cool.

.visuallyhidden

Add the .visuallyhidden class to hide text from browsers but make it available for screen readers. You can use this to hide text that is specific to screen readers but that other users should not see. About invisible content, Hiding content for accessibility, HTML5 Boilerplate issue/research.

.invisible

Add the .invisible class to any element you want to hide without affecting layout. When you use display: none an element is effectively removed from the layout. But in some cases you want the element to simply be invisible while remaining in the flow and not affecting the positioning of surrounding content.

.clearfix

Adding .clearfix to an element will ensure that it always fully contains its floated children. There have been many variants of the clearfix hack over the years, and there are other hacks that can also help you to contain floated children, but the HTML5 Boilerplate currently uses the micro clearfix.

Media Queries

The boilerplate makes it easy to get started with a "Mobile First" and Responsive Web Design approach to development. But it's worth remembering that there are no silver bullets.

We include a placeholder Media Queries to 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 a "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 MQs instead, e.g., @media only screen and (max-width: 480px).

Take a look into the Mobile Boilerplate for features that are useful when developing mobile wep apps.

Print styles

• Print styles are inlined to reduce the number of page requests.
• We strip all background colors, change the font color to black and remove text-shadow. This is meant to help save printer ink and make the printing process much faster.
• Anchors do not need colors to indicate they are linked. They are underlined to indicate so.
• Anchors and Abbreviations are expanded to indicate where users reading the printed page can refer to.
• But we do not want to show link text for image replaced elements (given that they are primarily images).

Paged media styles

• Paged media is supported only in a few browsers.
• Paged media support means browsers would know how to interpret instructions on breaking content into pages and on orphans/widows.
• We use page-break-inside: avoid; to prevent an image and table row from being split into two different pages, so use the same page-break-inside: avoid; for that as well.
• Headings should always appear with the text they are titles for. So, we ensure headings never appear in a different page than the text they describe by using page-break-after: avoid;.
• We also apply a default margin for the page specified in cm.
• We do not want orphans and widows to appear on pages you print. So, by defining orphans: 3 and widows: 3 you define the minimal number of words that every line should contain.