title: merge two CSS classes taking grid from one framework and style from another one
body: <p>I've read previous questions on this topic, but none of them ask what I'm trying to do. I'd like to merge two CSS classes (from two frameworks). More specifically I'd like to use the grid from one framework (like bootstrap) and style from another one. So when I style a button, for example, I want attributes related to locate an element in the view defined in the framework that I use for its grid system and attributes related to style from the other one. Here an example</p>
  <pre><code>.grid-class {
    definition1; // something related to width, margin padding
    definition2; // something like color, font-family
  }
  
  .layout-class {
   definition1; // something related to width, margin padding
   definition2; // something like color, font-family
  }
  </code></pre>
  <p>if I give grid-class layout-class to an element I'd like to have something like this:</p>
  <pre><code>.merged-class { // I do not need to create a CSS class on the fly
     definition1; // from grid class
     definition2; // from layout class
  }
  </code></pre>
  <p>I know that merge two frameworks is more complex, but <strong>I'd like to know if it's possible and how using JavaScript/TypeScript</strong>. I know which class is related with grid and which one is related with the layout because I'm using Angular and I have two binding like this:</p>
  <pre><code>&lt;my-component [grid]=&quot;grid classes&quot; [layout]=&quot;layout classes&quot;&gt;&lt;/my-component&gt;
  </code></pre>