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HTML

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CSS

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JavaScript

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HTML 

              
                <div class="container">
  <h1>Using :where() in a CSS Reset</h1>
  <p>In this example, I'm showing how I use the <code>:where()</code> <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/:where">pseudo class</a> to help make a CSS Reset in a design system. This is an extremely basic example. For more information, take a look at my <a href="https://leininger.tech/words/where-pseudo-class/">blog post</a> on the topic.</p>

  <p>In this example, the "Design System Styles" get overridden by a simple <code>a</code> selector. The goal is to show that using <code>:where()</code> makes it easier to update the styles lower in the cascase without having to fight <a href="https://polypane.app/css-specificity-calculator/">specificity</a>. <em>Comment out lines 27—39 in the CSS to see the "Design System Styles"</em>.</p>
</div>
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CSS 

              
                /* ----
	Design System Styles
---- */
/* specificity score: 0, 0, 1 */
a:where(:not([class])) {
  border-radius: 0.25rem;
  box-decoration-break: clone;
  color: darkcyan;
  text-decoration: underline;
  text-underline-offset: 2px;
  outline-color: lightseagreen;
}
a:where(:not([class])):where(:hover, :focus, :focus-visible) {
  color: rebeccapurple;
  text-decoration-color: darkcyan;
}
a:where(:not([class])):where(:focus-visible) {
  outline-offset: 0.25rem;
  outline-style: solid;
  outline-width: 2px;
}

/* ----
	In-App Styles - Lower in the cascade
---- */
/* specificity score: 0, 0, 1 */
a {
  color: hotpink;
  outline-color: palevioletred;
  // this sounds liks a taking back sunday lyric
}

/* specificity score: 0, 1, 1 */
a:hover,
a:focus,
a:focus-visible {
  color: midnightblue;
  text-decoration-color: hotpink;
}

//
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// Visual help!
body {
  color: slategray;
  font-size: clamp(1.13rem, calc(0.91rem + 0.9vw), 1.56rem);
  line-height: 1.5;
  margin: 2rem;
}
.container {
  max-width: 70ch;
  margin-inline: auto;
  padding-inline: 1.5rem;
}
h1 {
  color: DarkCyan;
  font-size: clamp(1.8rem, calc(0.83rem + 4.15vw), 3.82rem);
  line-height: 1.1;
  margin-bottom: 0;
}
code {
  background-color: #e6e6e6;
  border-radius: 0.25em;
  color: darkslategray;
  font-size: 0.95em;
  padding: 0.05em 0.125em;
}
::selection {
  background-color: darkcyan;
  color: white;
}
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JS
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