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Styleguide Notes


There are only two hard things in Computer Science: cache invalidation and naming things.
-- Phil Karlton


  • Working on a team.
  • Working on multiple projects and being able to understand the project when you come back to it.
  • Keep CSS maintainable.
  • Keep stylesheets scalable.
  • Documentation for the next developer on the system. Easier to transfer to another developer. Not required to be a mind reader anymore.
    • Code as comments have failed.

CSS/SCSS Architecture & Styleguide

  • Suggestions

    1. Modular - separation between components
    2. Legible - easy to read (think Python pep8)
    3. Clarity over succinctness - clear rather than clever.
    4. Flat - naming not too long
    5. Avoid conflicts - namespacing for components to avoid conflicts
  • Naming convention

    • .cn-{company-name} - global company name space. Company name not necessary if specific company
    • .c- - component .ui - component css .c-ui-slider
    • .l- - layout item - .l-grid-6
    • .is- or .has- - state of the item
    • .js- - JavaScript targeting. No style associated. Used for JS targeting (click, etc.)
  • BEM

    • Block - Element - Modifier
    • .cn-c-card__title - Block is .cn-c-card and Element is __title
    • .cn-c-alert--error - Block .cn-c-alert and modifier –error
  • Organization

    • Base styles
      • Rules for bare elements. Like normalizer. Keep it minimal
    • Objects
      • Focus on structure and layout. No decorative styles.
    • Components
      • Discrete, self-contained units of UI. Button or a carousel. Needs to be self contained. Drop anywhere on a page and it maintains its structure and design. (Name spacing)
    • State
      • Modify the state of a component (selected/not selected), open/close. Rather than adding or removing classes with JS, just change the state class.
    • Themes
      • Alter component (page) to use unique colors, fonts and decorations. Perception rather than structure. Entire page or just a component.
    • Utilities
      • Single purpose styling rule. Created for reuse. Minor changes to an existing component without changing the component. Make a specific instance of a component with a bold title rather than italic title for example.
    • JavaScript Hooks
      • Decouple js-hook classes from styling classes. Disconnect the tie between the two.
    • File organization
      1. Settings: Variables and other settings
      2. Tools: Custom functions and mixins
      3. Generic: Base styles
      4. Elements - Element defaults
      5. Objects - layout and structure
      6. Components - individual components
      7. Overrides - Final rules that might overrule previous rules.
  • SCSS rules

    • Limit nesting to 3 layers deep
    • What to nest
      • Modifiers of style block
        • .cn-c-alert { border: 1px solid gray; &--error { border: 1px solid red;}}
      • Media queries
      • Parent selectors
        • All rules for a component in one location
      • States
        • Component states in one location. hover, focus and active states included.
    • Use variables when values are used more than once.


  • Design Better Forms
    • Single column forms
    • Top align labels
    • Group labels with their inputs (put space between inputs)
    • Show all options if under 6 options
    • Resist using placeholders as labels.
    • Options and checkboxes should be placed under each other.
    • Make Call-To-Actions explicit
    • Specify inline-errors for forms.
    • Ditch * and denote optional fields excplicitly
    • Group related information.
  • Web From Usability: Top 10 Recommendations
    • Keep it short
    • Group related labels and fields
    • Fields in single column
    • Use logiical sequencing
    • Avoid placeholder text
    • Match fields to type and size of input (ie. zip code field should be small)
    • Distinguish between optional and required fields (explicit about what is optional)
    • Explain input or formatting requirements
    • Avoid reset, clear buttons. At least reduce visually prominence.
    • Provide visible and specific error messages.

Last update: April 13, 2020 15:25:03