JSFiddle - React, Tailwind, and code Playground

HTML

<div class="text">
  <h1>some text with <br> colorful gradient</h1>
</div>

CSS

body {
  background: black;
}
h1 {
  font-size: 120px;
  display: inline;
  line-height: 130px;
  position: relative;
  text-decoration: underline;
  background: linear-gradient(330deg, #ff6553 0, #ff1979 50%, #ffa400 100%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

h1::after {
  position: absolute;
  display: inline;
  content: "";
  width: 100%;
  height: 2px;
  background: white;
  bottom: 0;
  left: 0;
}