When thinking about what CSS framework to use for a new project, options like Bootstrap and Foundation readily jump to mind. They’re tempting to use because of their ready-to-use, pre-designed components, which developers can use with ease right away. This approach works well with relatively simple websites with a common look and feel. But as soon as we start building more complex, unique sites with specific needs, a couple of problems arise. At some point, we need to customize certain…