TLDR
In simple terms, your codes for a particular class should be named using Blocks. Blocks can interact with each other but they do not supersede each other. Block names could be in Latin letters, digits and dashes. To make it a CSS class, you have to add the block as a short prefix for name spacing. Add a modifier to the block will change the block in some way. An element is a child of the block and any codebase that is under the element is controlled by the block.via the TL;DR App
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