An eBook framework (CSS + template) which mantra is “finding simple solutions to complex issues.”
Blitz is released under MIT Licence © 2016, Jiminy Panoz.
- Readium SDK
- Adobe RMSDK
- iBooks
- Kobo
- Google Play Books
- Kindle (mobi7 + KF8)
There are various ways to use blitz, from adding the available stylesheets (CSS folder) to building them with the LESS framework.
You can either add blitz.css or an alternative stylesheet in your EPUB file.
blitz.css is commented but you’ll find an uncommented version in the AltStylesheets folder (which helps you save some 7kb).
In this folder, you’ll also find blitz-lite.css and blitz-reset.css (normal + minified).
blitz-lite.cssshould be enough for simple books like novels and essays (it’s 3kb);blitz-reset.cssis just… the reset we’ve designed (it’s 1kb).
Add styles on top of those two is up to you… But you’ll then miss the powerful tools we’ve built in LESS!
First go to the blitz root directory and install the dev dependencies:
npm install
Then make your changes in LESS and run:
npm run build
This will compile the LESS src to the default, lite and reset stylesheets, and update the template.
If you want to compile only one stylesheet you can run:
build:defaultfor the default output (blitz.css) – that will update the template’s unzipped src too;build:litefor the lite output (blitz-lite.css);build:resetfor the reset output (blitz-reset.css);
All those sub-builds will generate uncommented/minified files as well.
The Kindle stylesheet is not run automatically when building all. To generate this stylesheet, use npm run build:kindle – it will update the template’s unzipped src as well.
Finally, to update the packaged EPUB file then use npm run make.
Either use the GUI or, if you’re one of the old-school type…
lessc Blitz_framework/LESS/blitz.less Blitz_framework/CSS/blitz.css
lessc Blitz_framework/LESS/blitz-lite.less Blitz_framework/CSS/AltStylesheets/blitz-lite/blitz-lite.css
lessc Blitz_framework/LESS/blitz-reset.less Blitz_framework/CSS/AltStylesheets/blitz-reset/blitz-reset.css
Either uncomment @import 'blitz-kindle'; in blitz.less or, if you want to compile a specific kindle stylesheet:
lessc Blitz_framework/LESS/plugins/blitz-kindle.less Blitz_framework/CSS/blitz-kindle.css
You shouldn’t output them in blitz.css as legacy RMSDK (ePub 2) will ignore the entire stylesheet if there are media queries in it—excepted amzn queries.
lessc Blitz_framework/LESS/plugins/blitz-mq.less Blitz_framework/CSS/blitz-mq.css
- blitzck-cli – EPUB Reading Systems’ support, mimetypes, namespaces, and ARIA mappings from the command line interface
- The eBook Design Checklist – a progressive web app to help you design eBooks
- The eBook Performance Checklist – a progressive web app to help you boost eBook performance
- Blitz eBook Tricks – a collection of CSS snippets to help you do progressive enhancement in eBooks
Blitz was designed to deal with the significant obstacles a newcomer or even an experienced producer might encounter. Its major goals are:
- to be simple and robust enough;
- to offer a sensible default;
- to manage backwards compatibility (ePub 2.0.1 + mobi 7);
- to provide useful tools (LESS);
- to get around reading modes (night, sepia, etc.);
- to not disable user settings.
We have chosen a functional approach (FCSS) but LESS presets are planned to provide meaningful class names depending on eBook’s type (poetry, plays, etc.).
- Espouse inheritance and the cascade, the 2 fundamental principles of CSS. eBooks are documents, CSS was designed for documents… It’s a match!
- Build and refine, don’t style and undo. Don’t override your own styles, create reusable components—the reset should help you do that.
- Don’t fight, skirt. Be smart, it’s not worth fighting RS’ default stylesheets (their selectors and !importants are too much hassle), trompe le monde.
- Have fun! We’ve done our utmost to help you avoid common pitfalls. You don’t have to deal with the crappiest parts of eBook CSS authoring, sit back and relax.
Blitz is leveraging the concept of inheritance. Values inherit and currentColor are being used extensively to make the framework compatible with Reading Systems’ default stylesheets, reading modes (color) and user settings (font-size, font-family, line-height, etc.).
Defaults and a reset do the heavy lifting so it’s just about building on top of this base. Please note Blitz is taking care of defaults RS aren’t necessarily (HTML5 block elements, hyphens and pagebreaks for selected elements, etc.).
Finally, although we try to rely on RS’ typefaces, typography has been fine tuned.
- The default scale has been chosen to handle various situations well enough (screen/container size, user increasing
font-size, typeface used, etc.) - Vertical rhythm (
line-height+marginandpadding) is automatically computed in LESS to enforce consistency. By taking care of vertical rhythm, we’re also achieving horizontal harmony when the eBook is rendered on a (fake) spread: “everything text” lines up on the same baseline grid, which makes for a more comfortable reading experience. supandsubstyling is improved to prevent them from affecting line-height.- The whole §8. Breaking Within Words is implemented in LESS.
To sum up, we’ve tried to find a balance and feel like Blitz defaults can help producers get around a lot of possible issues: we don’t need hacks, we don’t have to change values in specific situations using complex media queries.
- The EPUB 3.1 spec should address common reader styling scenarios #671
- Defining a minimal default stylesheet in the epub spec #672
- Media Queries #685
- Possible spec language for reading system CSS handling #693
The following is a list of browsers/rendering engines modern EPUB apps are using behind the scenes. It is using the browserlist format and can be imported in websites such as CanIUse.
ie >= 11
edge >= 14
last 4 chrome major versions
safari >= 9.1
ios_saf >= 9.3
android >= 4.4
last 2 and_chr major versions
Alternatively, you can use this CanIuse Link.
When checking for support, you can simply click “Apply Filters” in order to display those browsers in the support table.
- IE 11’s Trident is used by some Windows app like Adobe Digital Editions 4.5
- Edge is aligned with the release of the eBook Reader in the Edge browser
- Safari on MacOS is aligned with the release of iBooks on Mavericks (10.9)
- Safari on iOS is starting at iOS 9.3
- Android 4.4.4 is still used by some apps on Android while others are using the more modern WebView (2 last Android versions)
- Progressive enhancements plugin is now implemented at the core of the LESS framework:
- removed support for font-variant-alternates;
- removed font-feature-settings properties;
- corrected negative (
not) feature queries
- Automated build with npm
- Removed gap after images
- Added DPUB ARIA roles in template
- Fixed hyphenation (limit chars)
- added reset styles for
hiddenattribute to improve backwards compatibility; - added a utility for
list-style-type: none; - an experimental plugin for progressive enhancements is now available (check docs).
- Added plugin for progressive enhancements.
- improved
hr.transition(won’t screw up vertical rhythm because margins any longer); -webkit-localenow an override (issue #9).
- refacto making the framework much easier to handle and customize (typo is now barebones)
- asterism is now an SVG background (beware! it’s an external dependency)
- CSS has been fine-tuned (e.g.
limit-lines, tabular numerals,object-fit, etc.) - added mixins to override and customize
list-style-type - prevented blank page at the end of xhtml in reset
- initialized docs (vanilla docs + API flavored reference)
- containers’ and images’ classes in
vhare now available - corrected epub namespace
- completed utilities (margins, underline, etc.)