css function calc () ,,,

https://www.runoob.com/cssref/css-functions.html

 

function	description	css version
attr()	Returns the value of an element selected attribute.	2
calc()	CSS allows calculation of property values, such as dynamic calculated length value.	3
linear-gradient()	Create an image of a linear gradient	3
radial-gradient()	Create an image with a radial gradient.	3
repeating-linear-gradient()	Create a duplicate image with a linear gradient.	3
repeating-radial-gradient()	Similar radial-gradient (), the image created by repeated radial gradient.	3

 

 

 

 

 

 

Use Calc () function calculates the <div> element width:

#div1 {
    position: absolute;
    left: 50px;
    width: calc(100% - 100px);
    border: 1px solid black;
    background-color: yellow;
    padding: 5px;
    text-align: center;
}