<div>
  <h1>Welcome</h1>
</div>

h1 {
  font-size: clamp(1rem, 10vw, 2rem);
  border: black 1px solid;
  background-color: hsl(200, 100%, 60%);
  width: 100%;
}

div {
  padding: clamp(10px, 6vw, 50px);
  width: clamp(140px, 90vw, 600px);
  height: 100vh;
  box-sizing: border-box;
  background-color: hsl(200, 100%, 80%);
  border: black 1px solid;
}