<button>A button</button>

<article>
  <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Suscipit deserunt molestias porro quae eveniet. Veniam laboriosam rem sunt voluptates accusamus nobis, quia labore quisquam corrupti maxime modi nemo minus vitae?</p>
  <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Suscipit deserunt molestias porro quae eveniet. Veniam laboriosam rem sunt voluptates accusamus nobis, quia labore quisquam corrupti maxime modi nemo minus vitae?</p>
</article>

@layer demo {
  button {
    padding-inline: 2ch;
    padding-block: 1ch;
  }
  
  article > p {
    text-align: start;
    margin-block: 2ch;
  }
}

@layer demo.support {
  * {
    box-sizing: border-box;
    margin: 0;
  }

  html {
    block-size: 100%;
    color-scheme: dark light;
  }

  body {
    min-block-size: 100%;
    font-family: system-ui, sans-serif;

    display: grid;
    place-content: center;
    place-items: start;
    padding: 5vmin;
  }
  
  p {
    max-inline-size: 40ch;
  }
}