Does REM make sense on border-radius? [closed]

Question

I'm using REM units for my project. I would like to use a uniform type of units for all the project. I'm working with a group of developers and I'm trying to find a reason why I would have to apply REM units in all the CSS rules, but sometimes I maybe find it excessive or completely useless.

I would like to know if the following is necessary, benefits or disadvantages:

input{
    border-radius: 0.5rem;
    display: block;
    margin: 0 0 2rem 0;
    min-width: 12rem;
    height: 4rem;
    padding: 0 2rem;
    width: 100%;
}

In this example you can see the border-radius is 5px as the HTML has applied font-size: 62.5% to have an easier method applying the REM units.

Answer 1

There is no technical reason not to use the rem unit for border-radius. Neither is never any compelling reason to use the rem unit, for it or otherwise. Using rem is merely something chosen for convenience, as it may help to avoid computing multipliers for the em unit, at the cost of reduced cross-browser functionality.

It is generally safest to use the same unit for different dimensions, and this applies to border-radius, too, when the height and width of the element have been set in rem units. The reason is that this ensures that the shape is preserved if the font size of the root element is changed. If you set the border-radius e.g. in px units and width and height in rem units and the font size of the root element is then set to, say, 32pt, the element box becomes rather large but the border curvature remains small.