Fluid Project is evaluating CSS Frameworks as a possible tool:

After a research and evaluation period (see: CSS Framework Research Notes), Foundation and Bootstrap have emerged to be the front runners. This attempts to document in detail the requirements of the framework to be used.

Criteria Evaluation


Feature / Desired applicationBootstrapFoundation
Responsive layouts
  • Bootstrap uses fixed width containers that "snap" across breakpoints
  • Grid layout needs to follow a container-row-column hierarchy. Otherwise 15px paddings / margins don't align properly.
  • Foundation uses fluid width containers that stretch and shrink depending on the size of the client, with relevant breakpoints.
  • Foundation has a row-column hierarchy with paddings on the columns only. Row is only for containment.
Style reset
  • normalize.css is included in default package, but optional whether or not it is used in your markup.
Units in EMs

Current release (v3) uses pixels and not EMs. However, v4 (unreleased) will support EMs. See Mark Otto's January 9th response in this thread on Github.

  • Note: EMs will be supported. Unclear if REMs will be used.
  • UIO works well with Bootstrap's pixel units, although EMs are more desirable.
Foundation 5 uses REM units throughout. The exception being media queries which use EM units.
  • REMs are desirable and easier to use for CSS styling than EM because REMs always refer to the root EM and not the parent EM as with EM units.
  • REM units currently do not scale properly in UI Options. See
Ease of using default styles in a heavily customized application
  • +/-15px margin and padding on container, rows, and columns dictate a hierarchy and usage pattern. Customizing this or deviating from this pattern causes unintentional and unwanted alignment issues which can be hard to correct (involves overriding).
  • This hierarchy is required to ensure good scalable layouts.
  • Working with Foundation within a heavily customized application seemed very straight forward. Some styles needed to be overridden, but that was expected.
  • Foundation button has !important for font weight
Use of !important
  • important used for print media styling, visibility of collapsing navbar, and visible and hidden elements.
  • no use of !important on html elements
  • Important primarily used to position starting and ending Foundation classes such as offsets, start and end of navigation containers, hide/show elements (i.e. "hide-for-large"), and custom components (like Joyride widget).
  • Uses of !important on html elements
    • button: font-weight: normal !important;
    • select: webkit - appearance: none !important;

Namespacing framework classnames
  • Bootstrap uses generic classnames which may cause classname collisions.
  • A work-around is to use LESS or Sass to add a named container. See this as a possible solution: https://coderwall.com/p/uiwcow

UIO Theme generation

  • Themes can be created using the online tool but it is not a quick process and error prone: http://getbootstrap.com/customize/
  • Themes can also be created by modifying the variables.less file
  • There are a lot of variables to configure, experimentation will be needed to determine the effect of each variable and which variables should be modified for a theme.
  • Background colour can not be changed using the online customization tool: http://foundation.zurb.com/develop/download.html#customizeFoundation
  • Themes can be created by modifying the _settings.scss file
  • There are a lot of variables to configure, experimentation will be needed to determine the effect of each variable and which variables should be modified for a theme.
Effects of custom Foundation build with another framework 
  • REM sizing may be an issue (see below)
  • Namespace collisions make integrating another framework difficult
Possible Learner Prefs with CSS Framework
  • Bootstrap components can be turned into a Learner Preference.
  • For example:
    • Linearize / stack content by changing the grid layout
    • Navigation bar preferences: make tabs look like pills, make navigation pills stack
    • Pager: size, appearance, spacing
    • Alerts: change the way alerts are positioned or styled (i.e. make them bigger, put them in a floating panel etc.)
    • Hide / show screenreader-only content (elements with "sr-only" class).

  • Like Bootstrap, Foundation features can be turned into Learner Preferences
  • For example:
    • Linearize / stack content by changing grid layout
    • Reposition side navigation
    • Turn sub-nav (frequently used for filtering lists) from horizontal list into a drop-down menu.
    • Change the way link-buttons (links that look like buttons) appear
    • Make progress bars bigger and appear in different colours.
Example implementation of Fluidproject.org designhttps://github.com/acheetham/fluidproject.org/tree/FLUID-5261https://github.com/jhung/fluidproject.org/tree/FLUID-5262


Use Case Exploration

There are currently some unresolved user questions:

To explore answers to these questions, the following 4 use cases are possible:

  1. Integrator is not using any framework but chooses to use our component.
  2. Integrator adopts and uses the framework used by our component.
  3. Integrator is using the same framework as our component, but with different customizations (essentially two versions of the same framework exists on the same page).
  4. Integrator is using a different framework than the one used by our component.

To attempt to figure out the consequences of use cases 3 and 4, a custom version of Foundation (linked below) was created that is scoped to a mock Infusion component with the classname ".inf-foundation" on the container. 

Findings: REM units and Root

Issue: REM sizes may not look proper when adding styles with REM units to a document where the root element has existing font-size specified. 


It is possible that the document in which an Infusion component is being added to already have a root font-size specified. In which case any REM sizes used in the Infusion component will size itself relative to that existing root font-size. If the font-size is not an expected value, the Infusion component may not look as expected.


Bootstrap specifies font-size: 62.5% on the HTML element, and a font-size: 14px to the Body element. Adding an Infusion component (which is using Foundation) with a font-size: 1rem to this document would have the Infusion component appear smaller since 1rem is relative to the 62.5% font-size value on the HTML element.

Findings: Mixing Frameworks within the same scope

Issue: Without proper namespacing of framework classnames, it is difficult to mix two frameworks in the same scope.


If the integrator wants to customize an Infusion component (which is already using a custom Foundation) using their own framework, namespace collisions may be unavoidable. Therefore Infusion's use of a CSS framework should be properly name spaced to ensure it doesn't get in the way of an integrator's customizations.