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[thing] = required the concept the class name is referring to at the most general yet still meaningful level (eg. fl-tabs, fl-widget, fl-component, fl-col, fl-container, etc)
[role] = optional the purpose or action of THING, which could be a more detailed version of THING (eg. fl-tabs-centered, fl-col-flex, fl-container-500, fl-widget-titleBar)
[state] = optional a modifier of the ROLE or THING, which is only temporary and dependant on other actions (eg. fl-button-left-disabled, fl-widget-content-draggable)
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