Modular CSS frameworks

A fair number of the CSS frameworks I’ve seen – Blueprint, Tripoli, YUI, SenCSS – are monolithic. What I’d like is to be able to mix and match specific components of these.

For example, has a simple grid system that I’d love to combine with the vertical rhythm that SenCSS offers. (Vertical rhythm ensures that sentences align vertically.) I’d love to have a CSS framework that just sets the fonts, for example, and touches nothing else. Or something that defines the colour schemes, and lets you change the theme like Microsoft Office does.


Less CSS has been invaluable in helping with this. It extends the CSS language without deviating significantly from it. Compared to SASS and CleverCSS, I’d say it has a better chance of getting incorporated as into, say, CSS4.

LessCSS offers variables. I can define a variable:

@foreground: #112233

and use it like this:

h1 { color: @foreground; }
a:hover { background-color: @foreground; }

When I change @foreground, it’s replaced everywhere.

LessCSS offers multiple inheritance.

.highlight { color: red; }
.button { border-radius: 10px; }
.action {

This assigns the properties of the highlight and the button classes to the action class. Any changes made to the parents automatically get inherited.

LessCSS has a Javascript pre-processor. So I can include it directly in the HTML, and add the pre-processor, which converts it into CSS.

<link rel="stylesheet/less" href="style.less">
<script src="less.js"></script>

I now use LessCSS as the basis of all new projects.

CSS libraries

My first attempt to consolidate modular CSS libraries is at As far as possible, I’ve tried to avoid creating new libraries, or even tweaking existing ones. Over time, I hope to completely eliminate any new code.

There are two types 2 types of libraries. Some just have variable definitions. Others actually define styles. For example, I’ve got three libraries that just define variables:


Defines a standard set of color themes (based on the Office 2007 color themes)


Defines Web-safe font stacks (based on Sitepoint’s article)


Transparent background patterns (randomly useful images)

Including the above libraries will have no effect. You need to explicitly use them. For example:

@import "font_stacks.less";         // Does nothing
h1 { font-family: .font[@serif]; }  // Makes H1 a serif font

The following libraries define styles. Including them will define new classes or change the style of tags / classes.


Resets default styles consistently across browsers. I chose YUI3 CSS Reset arbitrarily. I think HTML5boilerplate’s CSS reset may be a better choice, though.


Defines classes for fixed and fluid grids. I choose YUI3 CSS Grids over (which I’ve used for some years) because of its ability to offer fixed as well as fluid layouts, and the sheer brilliance of its minimality.


Sets font sizes, ensuring that lines have a vertical rhythm. This is a stripped-down version of SenCSS, but over time, I’ll phase this out and use some standard framework someone comes up with.

Between these, I think the base infrastructure for most applications is in place. What’s required next are widgets. Specifically, I’d like:

  • Buttons. A really good, cross-browser, non-image-based button that offers rounded corners, gradients and borders.
  • Forms. Consistent form styling, without forcing me to use a specific form layout.
  • Icons. A standard icon library with replaceable CSS sprite-sets.

I’ll try keep the code updated as I find these. Do pass me any suggestions you may have.

  1. Abhishek Singh says:

    This is really cool… I think i wont be facing any build kit issues from now on 🙂