Resizing Values in Steps in CSS

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There actually is a steps() function in CSS, but it’s only used for animation. You can’t, for example, tell an element it’s allowed to grow in height but only in steps of 10px. Maybe someday? I dunno. There would have to be some pretty clear use cases that something like background-repeat: space || round; doesn’t already handle.

Another way to handle steps would be sequential media queries.

@media (max-width: 1500px) { body { font-size: 30px; }}
@media (max-width: 1400px) { body { font-size: 28px; }}
@media (max-width: 1300px) { body { font-size: 26px; }}
@media (max-width: 1200px) { body { font-size: 24px; }}
@media (max-width: 1000px) { body { font-size: 22px; }}
@media (max-width: 900px) { body { font-size: 20px; }}
@media (max-width: 800px) { body { font-size: 18px; }}
@media (max-width: 700px) { body { font-size: 16px; }}
@media (max-width: 600px) { body { font-size: 14px; }}
@media (max-width: 500px) { body { font-size: 12px; }}
@media (max-width: 400px) { body { font-size: 10px; }}
@media (max-width: 300px) { body { font-size: 8px; }}

That’s just weird, and you’d probably want to use fluid typography, but the point here is resizing in steps and not just fluidity.

I came across another way to handle steps in a StackOverflow answer from John Henkel a while ago. (I was informed Star Simpson also called it out.) It’s a ridiculous hack and you should never use it. But it’s a CSS trick so I’m contractually obliged to share it.

The calc function uses double precision float. Therefore it exhibits a step function near 1e18… This will snap to values 0px, 1024px, 2048px, etc.

calc(6e18px + 100vw - 6e18px);

That’s pretty wacky. It’s a weird “implementation detail” that hasn’t been specced, so you’ll only see it in Chrome and Safari.

You can fiddle with that calculation and apply the value to whatever you want. Here’s me tuning it down quite a bit and applying it to font-size instead.

Try resizing that to see the stepping behavior (in Chrome or Safari).