The rem() CSS function returns a remainder left over when the first parameter is divided by the second parameter, similar to the JavaScript remainder operator (%). The remainder is the value left over when one operand, the dividend, is divided by a second operand, the divisor. It always takes the sign of the dividend....values */ rotate: rem(200deg, 30deg); /* 20deg */ rotate: rem(140deg...50deg */ rotate: rem(-90deg, 20deg); /* -10deg */ rotate: rem(-55deg...