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HTML 

              
                <header>
  <h1>Demo of <code>text-box</code></h1> 
  <div class="toggle">
    <label for="guides">Show guides: </label>
    <input type="checkbox" switch id="guides">
  </div>
</header>
<main>
  <article>
    <figure>
      <img src='https://images.unsplash.com/photo-1733108906414-fde4a7596456?crop=entropy&cs=srgb&fm=jpg&ixid=M3wzMjM4NDZ8MHwxfHJhbmRvbXx8fHx8fHx8fDE3MzMzMzk0NDN8&ixlib=rb-4.0.3&q=85' alt=''>
      <h2 class="name">Holiday Decorations</h2>
      <p>Lorem ipsum odor amet, consectetuer adipiscing elit. Consectetur sed laoreet ad gravida egestas; potenti posuere dignissim. Turpis nostra taciti ornare imperdiet felis ante fusce ridiculus. Fringilla praesent felis blandit amet morbi rhoncus odio torquent torquent?</p>
      <figcaption><code>text-box: normal</code></figcaption>
    </figure>
    <figure class="trimmed">
      <img src='https://images.unsplash.com/photo-1733108906414-fde4a7596456?crop=entropy&cs=srgb&fm=jpg&ixid=M3wzMjM4NDZ8MHwxfHJhbmRvbXx8fHx8fHx8fDE3MzMzMzk0NDN8&ixlib=rb-4.0.3&q=85' alt=''>
      <h2 class="name">Holiday Decorations</h2>
      <p>Lorem ipsum odor amet, consectetuer adipiscing elit. Consectetur sed laoreet ad gravida egestas; potenti posuere dignissim. Turpis nostra taciti ornare imperdiet felis ante fusce ridiculus. Fringilla praesent felis blandit amet morbi rhoncus odio torquent torquent?</p>
      <figcaption><code>text-box: trim-start cap</code></figcaption>
    </figure>
  </article>
 </main>



<aside class="no-support">This is a demo of <code>text-box</code>. If you are reading this message, your browser does not have support. Please try this in Safari 18.2 or another <a href="https://caniuse.com/css-text-box-trim">browser with support</a>.</aside>
!

CSS 

              
                
article .trimmed h2 {
  text-box: trim-start cap;
}

article {
  display: grid;
  grid-template-columns: repeat(auto-fit, 78ch);
  gap: 4rem;
  figure {
    margin-block-end: 2rem;
    min-width: 600px;
    margin: 0;
  }
  figcaption {
    font-size: 200%;
    text-align: center;
    margin-block-start: 2rem;
    color: light-dark(rebeccapurple, hotpink); 
  }
  img { 
    width: 320px;
    float: left;
    margin-inline-end: 1.5em;
    margin-block-end: 0.45em; 
  }
  h2 {
    font-family: "Ewert";
    font-size: 2.8rem;
    margin-block: 0;
    line-height: 1.1;
  }
  p {
    font-size: 0.9rem;
    font-family: Merriweather, georgia, serif;
    line-height: 1.6;
    margin: 0.95em 0 0;
  }
  .trimmed figcaption {
    margin-top: calc( 2rem + 9px);
  }
}

/*---  Guide  -------------------------------*/
figure {
  border-top: 3px solid canvas;
}
body:has(input[id="guides"]:checked) {
  figure {
    border-top: 3px dotted #00e8e8;
  }
}

/*-------------------------------------------*/
/*   Overall page and UI                     */
/*-------------------------------------------*/

:root {
  color-scheme: light dark;
}
body, button {
  font-family: system-ui, sans-serif;
}
body {
  margin: 4rem;
}
header {
  display: flex;
  justify-content: space-between;
  align-items: start;
}
header h1 code {
  font-size-adjust: 0.64;
  padding-inline: 4px;
  color: light-dark(rebeccapurple, hotpink);
}
.toggle {
  margin-block: 1lh;
  padding: 0.25lh 0.75lh;
  border: 1px solid #00e8e8;
  min-width: max-content;
  border-radius: 1lh;
  font-size: 1.1rem;
  font-weight: 300;
  accent-color: #00e8e8;
  display: flex;
  align-items: center;
  label {
    margin-inline-end: 0.5em;
  }
}
main {
  display: grid;
  gap: 6rem;
  margin-block-start: 2rem;
/*   width: 1700px; */
}

/*-------------------------------------------*/
/*   Browser support message                 */
/*-------------------------------------------*/

@supports (text-box: trim-start cap) {
  .no-support {
    display: none;
  }
}
.no-support {
  padding: 1rlh;
  background: darkred;
  color: white;
  font-family: system-ui, sans-serif;
  a {
    color: white;
    text-decoration: underline;
  }
}
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