Start using @supports

Writing @supports can be laborious, but there’s a plus side in long-term development. If you expect your project to last an eternity, it can be very beneficial.

Imagine that you are writing some new aspect ratio code for well… images… if you use @supports, you will probably have to write two bits of CSS just to handle it.

.aspect-ratio-16-9 {
    padding-bottom: 56.25%;
}

@supports(aspect-ratio: 16 / 9) {
   .aspect-ratio-16-9 {
       padding-bottom: 0;
       aspect-ratio: 16 / 9;
    }
}

Why would you want to do that to yourself? Well, think of the future you in a few years. You start using aspect-ratio left right and centre, with no considerations in mind. But once upon a time, you did care.

Well, if you wrote a @supports - you can easily find old dead code you no longer need. You can remove the support, and remove the old class. Everything is updated, with no further changes.