Arithmetic Calc ()

It's really quite a surprise, and it's good for percent width. We had box-sizng before, and now we have one more, and Calc is more practical. We can do some subtraction on attributes such as border, margin, pading, font-size and width, and simply take the width example:

{Background-color: #dee; height: 200px; padding: 40px; display: inline-block; width: calc (100%-2 * 40px);}

Notes for writing:

Width:calc (100%-2*40px);//Wrong wording

(This is the pit I stepped on during the test →→)

operator to add a space before or after the browser may not be recognized yo ~ ~

Others seem to have nothing, finally look at compatibility,:)

Arithmetic Calc ()