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HTML

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CSS

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                <div class="container fluid">
  <h1>:where() and specificity</h1>
  <h2>The h2s being overridden</h2>
  <p>In this example, I'm using fluid text styles as a default for the all body copy, h1, and h2 tags. I am using <code>:where(.fluid)</code> selector on the body and the h2, but I'm using plain <code>.fluid</code> selector on the h1 tag. Anything <code>:where()</code> is computed with 0 specificity.</p>
  <h2>Check the CSS lines 22—43</h2>
  <p>Lower in the CSS file, I'm "overriding" the h1 and h2 to change their colors and size, but you'll notice that the h2 tags are the only ones that change. If you check at lines 22—43, you'll see that the the h2 selectors are more specific than the <code>:where(.fluid) h2</code> selectors. That is why we have static h2 sizing and different colors from our initial declaration. You can find more infomation about this on <a href="https://leininger.tech/words/where-pseudo-class/">my blog</a>.</p>
</div>
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CSS 

              
                /* specificity score: 0, 0, 1 */
body {
  font-size: 1rem;
  color: lightslategray;
}

/* specificity score: 0, 0, 1 */
body :where(.fluid) {
  font-size: clamp(1rem, calc(0.88rem + 0.51vw), 1.25rem);
}

/* specificity score: 0, 0, 1 */
h1 {
  font-size: 2rem;
  color: RebeccaPurple;
}
h2 {
  font-size: 1.5rem;
  color: RebeccaPurple;
}

/* specificity score: 0, 1, 1 -- pseudo-class */
.fluid h1 {
  font-size: clamp(1.6rem, calc(0.9rem + 2.99vw), 3.05rem);
  color: DarkCyan;
}

/* specificity score: 0, 0, 1 */
:where(.fluid) h2 {
  color: DarkCyan;
  font-size: clamp(1.42rem, calc(0.93rem + 2.1vw), 2.44rem);
}

/* specificity score: 0, 0, 1 this loses to .fluid h1 */
h1 {
  font-size: 4rem;
  color: darkslategray;
}
/* specificity score: 0, 0, 1 this overrides :where(.fluid) h2 */
h2 {
  font-size: 3rem;
  color: darkslategray;
}

//
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// Visual help!
body {
  line-height: 1.5;
}
.container {
  max-width: 70ch;
  margin-inline: auto;
  padding-inline: 1.5rem;
}
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;
}
/* :is() takes the highest specificity score of the included selectors.
This has a specificity score: 0, 0, 1 */
:is(h1, h2) {
  line-height: 1.1;
  margin-bottom: 0;
}
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;
}
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JS
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999px

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