. calc() Function in CSS:

The calc() function is used to perform calculations in CSS. It allows you to combine different units (like percentages, pixels, em, etc.) and perform arithmetic operations (+, -, *, /) to create dynamic layouts.

Syntax:

width: calc(100% - 50px);

Example:

You might use calc() to set the width of an element based on the viewport size, but subtract some fixed value like a sidebar width:

.main {
  width: calc(100% - 200px); /* 100% width minus 200px */
}