Use Svelte shorthand for CSS variables declaration

src/components/SplitText.svelte

@@ -16,7 +16,7 @@
             {#each Array(2) as _, index}
                 <span class="text-split__line" aria-hidden={index === 1}>
                     {#each split as word, i}
-                        <span class="word" style="--i-w: {i};">{word}</span>{#if word.includes('\n')}<br>{/if}
+                        <span class="word" style:--i-w={i}>{word}</span>{#if word.includes('\n')}<br>{/if}
                         <!-- svelte-ignore empty-block -->
                         {#if i < split.length - 1}{/if}
                     {/each}
@@ -36,7 +36,7 @@
 {:else}
     <span class={classes}>
         {#each split as char, i}
-            <span class="char" style="--i-c: {i};">{char}</span>
+            <span class="char" style:--i-c={i}>{char}</span>
         {/each}
     </span>
 {/if}