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Clamp

Restrict a number between two other numbers.

clamp(MIN, VAL, MAX)
translates as
max(MIN, min(VAL, MAX))
// 5
clamp(2, 5, 10); 

// 137
clamp(137, 5, 5000); 

// 1
clamp(0, 50, 1); 
// given 1em = 16px, 4em = (16px * 4) = 64px
width: clamp(10px, 4em, 80px);
// If 2.5vw is less than 1rem, the font-size will be 1rem.
// If 2.5vw is greater than 1.5rem, the font-size will be 1.5rem.
// Otherwise, it will be 2.5vw.
font-size: clamp(1rem, 2.5vw, 1.5rem);