JSFiddle - React, Tailwind, and code Playground

by Alex

HTML

<header>
  <h1>Teste de Gradiente 45º em CSS3</h1>
</header>

CSS

header::before {
  background-image: linear-gradient(-150deg, transparent, #000, #000 100px, transparent 100px, transparent);
  background-size: 3px 3px;
  content: '';
  display: block;
  height: 25px;
  width: 100%;
}
header::after {
  background-image: linear-gradient(-45deg, transparent, #000, #000 1px, transparent 1px, transparent);
  background-size: 3px 3px;
  content: '';
  display: block;
  height: 25px;
  width: 100%;
}