how to make fonts respnsive

1h1 {
2  font-size: clamp(16px, 5vw, 34px);
3}

1/* Uses vh and vm with calc */
2@media screen and (min-width: 25em){
3  html { font-size: calc( 16px + (24 - 16) * (100vw - 400px) / (800 - 400) ); }
4}
5
6/* Safari <8 and IE <11 */
7@media screen and (min-width: 25em){
8  html { font-size: calc( 16px + (24 - 16) * (100vw - 400px) / (800 - 400) ); }
9}
10
11@media screen and (min-width: 50em){
12html { font-size: calc( 16px + (24 - 16) * (100vw - 400px) / (800 - 400) ); }
13}