CSS

We use Sass for our CSS Preprocessor
itcss CSS architecture
More Minimal BEM like CSS Syntax: .block_element -modifier
More Transparent UI Code with Namespaces

Sass import order

Settings: Global variables, site-wide settings, config switches, etc.
Tools: Site-wide mixins and functions.
Generic: Low-specificity, far-reaching rulesets (e.g. resets).
Base: Unclassed HTML elements (e.g. a {}, blockquote {}, address {}).
Objects: Objects, abstractions, and design patterns (e.g. .o-media {}).
Components: Discrete, complete chunks of UI (e.g. .c-carousel {}).
Trumps: High-specificity, very explicit selectors. Overrides and helper classes (e.g. .u-hidden {}).

Grid

We are using a simple inline-block grid system.

Usage

Insert a o-grid block and add o-grid_item elements inside it. No rows that contain floats, no twelve columns system; just the number of items you want, with the classes names you want, inside a single block.

Include the grid mixins in your components classes.
Create custom width grid items by including the grid_item mixin and adding the widths you need or just include the helpers mixins with fractions like names.
Add media queries, on the helpers mixins or on your custom components to change the grid items widths, for your content, on different screen sizes.

Demo

Form

We included some basic CSS styles and resets to the form elements so we can easily have custom style form elements that work on every browsers.

Demo

JavaScript

We use HTML data attributes to init our JavaScript modules: data-module
All DOM related JavaScript is hooked to js- prefixed HTML classes
jQuery is globally included