USING HTML AND CSS

Hello @AMANDEEPSINGHBHALLA nice work

But is an observation and tip

-the background color is meant to cover your entire body

and for the grey color to cover the entire screen you have to remove the width and height you set to the mainf container so instead of

.mainf{
  width: 80vw;
  height: 80vh;
  margin: 4rem auto;
  background-color: hsl(212, 45%, 89%);
  display: flex;
  align-items: center;
  justify-content: center;
}

- why not do this

.mainf{
  display: flex;
  align-items: center;
  justify-content: center;
}
- I removed the height, width,  margin, and background-color

body{
  margin: 4rem auto;
  background-color: hsl(212, 45%, 89%);
}

- added the margin and background to the body element

• i believe this will make your project more visually appealing but other than that your work is neat