I don't use Bootstrap. I decided to abandon it because Bootstrap is inconvenient and limits me too much. When I write a simple CSS rule and insert a block inside Bootstrap, I see that it doesn't work. Bootstrap overwrites classic CSS rules, and things that work in regular CSS stop working for me.

The second reason is that it complicates the HTML and CSS layout. Why define different class names in HTML for different types of devices when you can simply create a single class name, for example

.fix

and write everything else in CSS, setting size constraints for different device types with CSS rules

style.css

.fix {
  margin: 0 auto;
  max-width: 1024px;
}

mobile.css

@media (max-width: 768px) {
  .fix {
    width: 100%;
  }
}

And if you just need to make a simple one-page website, why connect such a huge library like Bootstrap when you can just write a few lines in regular HTML and CSS?

That is exactly why I made this minimalist qCSS framework. It's not even a framework, but just a set of styles that allows you to create simple HTML pages, but it can also be used in large projects. I, for example, used it to speed up the page loading of an online store, and it worked.

Everything is so simple there that you can just look at ready-made examples, and everything will become clear. Just open the style file and read what is written there. Open it and see what the layout looks like.

Here are ready-made examples:
a blog example
a one-page website example
dropdown menu
sticky footer

Swap sidebar

Let's say you have a blog with a sidebar on the right and content on the left, like this. And you want to swap the sidebar on the left and the content on the right. It's very easy to do.

.content {
float: right;
}
.ss {
margin-left: 0px;
margin-right: 50px;
}

Swap blocks

Here's another example. Let's say you have three blocks, like the ones in the Features block, and you want to swap the first and second blocks, then you'd use these rules.

Swap first & second blocks

.first{
    left: 33.3333%;
}
.second{
    left: -33.3333%;
}

Swap first & third blocks

.first{
    left: 66.6666%;
}
.third{
    left: -66.6666%;
}

Swap second & third blocks

.second{
    left: 33.3333%;
}
.third{
    left: -33.3333%;
}

Conclusion

My approach differs from Bootstrap because

I created the HTML layout of the page, closed it once and never opened it again.
All changes are made in two files: style.css and mobile.css.

I try to stick to a simple rule: Don't complicate things! Simplify.