Example 1: responsive font-size

/* please refer to https://developer.mozilla.org/fr/docs/Web/CSS/clamp() */
font-size: clamp(40px, 10vw, 70px); /* clamp(MIN, VAL, MAX) */

Example 2: how to make fonts respnsive

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

Example 3: how to make font responsive

html { font-size: calc(1em + 1vw); }

Example 4: responsive text css

Responsive Text

Resize the browser window to see how the text size scales.