Helpers

Helpers are a collection of useful classes.

# Available classes

Hiding
`.hidden`
`.hidden--mobile`
`.hidden--phone`
`.hidden--tablet`
`.hidden--desktop`
Visibility
`.visible--mobile`
`.visible--phone`
`.visible--tablet`
`.visible--desktop`
Media
`.img--rwd`
`.img-circle`
`.video--rwd`
Positioning
`.inline-left`
`.inline-left--phone`
`.inline-right`
`.inline-right--phone`
`.inline-center`
`.inline-center--phone`
`.inline-justify`
`.inline-justify--phone`
`.block-center`
`.vertical-top`
`.vertical-middle`
`.vertical-bottom`
`.float-right`
`.float-left`
`.box--flex`
`.box--flex--wrap`
`.full-width`	full Width Containers in Limited Width Parents (reference)
`.object-fit--cover`	object-fit references ( CSS tricks, object-fit and Flexbox on CodePen)
`.object-fit--fit`
`.object-fit--contain`
Others
`.no-margin`
`.radius-none`
`.link-neutral`	href color as default color of text
`.truncate`	truncating text using `text-overflow: ellipsis`
`.mate-blink`	useful for focusing user eyes on changed element