Most WordPress blocks allow to enter rich text, which means you can make selected text bold, italic, add links or even inline images. This functionality can be leveraged to style parts of the text with Tailwind classes.
Select some text and make it italic with the rich text formatting controls which appear on the right side of the block toolbar:

Using the Italic format essentially wraps the part of the text with the <em> HTML element. This element can be styled with Tailwind classes.
[&_em]:not-italic [&_em]:text-primaryOr using a selector:
ska-blocks:{"skaBlocksSelectors":{"[&_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksTextColor":{"v":{"$":{"@":"primary"}}}}}} When pressing Shift + Enter in a rich text input you can add a new line – creating a <br> tag – these can also be “styled” using a Tailwind class such as max-sm:[&>br]:hidden to control what screen sizes use line breaks.
For more granular control of the HTML markup use multiple Text blocks (as <span>, <kbd>, <abbr>, etc elements) inserted into an Element block (rendered as <span> or <p> elements). Entering HTML markup directly into the Tailwind block and pressing “Convert to blocks” can be used as a shortcut to produce the blocks you need.
Examples
Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"[\u0026_em]:not-italic [\u0026_em]:text-primary","css":".\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:text-primary em{color:var(--color-primary)}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksTextColor":{"v":{"$":{"@":"primary"}}}}}} -->
<h2 class="[&_em]:not-italic [&_em]:text-primary wp-block-heading">Test <em>heading</em>, please ignore</h2>
<!-- /wp:heading -->Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"lg:text-5xl [\u0026_em]:not-italic [\u0026_em]:underline [\u0026_em]:decoration-primary/50 [\u0026_em]:decoration-solid [\u0026_em]:decoration-6 [\u0026_em]:underline-offset-4 [\u0026_em]:hover:underline-offset-8 [\u0026_em]:transition-[text-underline-offset] [\u0026_em]:hover:animate-pulse","css":"@media (min-width:64rem){.lg\\:text-5xl{font-size:var(--text-5xl);line-height:var(--tw-leading,var(--text-5xl--line-height))}}.\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:underline em{text-decoration-line:underline}.\\[\\\u0026_em\\]\\:decoration-primary\\/50 em{text-decoration-color:#2ba2e580}@supports (color:color-mix(in lab, red, red)){.\\[\\\u0026_em\\]\\:decoration-primary\\/50 em{-webkit-text-decoration-color:color-mix(in oklab,var(--color-primary)50%,transparent);-webkit-text-decoration-color:color-mix(in oklab,var(--color-primary)50%,transparent);text-decoration-color:color-mix(in oklab,var(--color-primary)50%,transparent)}}.\\[\\\u0026_em\\]\\:decoration-solid em{text-decoration-style:solid}.\\[\\\u0026_em\\]\\:decoration-6 em{text-decoration-thickness:6px}.\\[\\\u0026_em\\]\\:underline-offset-4 em{text-underline-offset:4px}@media (hover:hover){.\\[\\\u0026_em\\]\\:hover\\:underline-offset-8 em:hover{text-underline-offset:8px}}.\\[\\\u0026_em\\]\\:transition-\\[text-underline-offset\\] em{transition-property:text-underline-offset;transition-timing-function:var(--tw-ease,var(--default-transition-timing-function));transition-duration:var(--tw-duration,var(--default-transition-duration))}@media (hover:hover){.\\[\\\u0026_em\\]\\:hover\\:animate-pulse em:hover{animation:var(--animate-pulse)}}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksTextUnderlineOffset":{"v":{"$":{"@":"4"},"hover":{"@":"8"}}},"skaBlocksTextDecoration":{"v":{"$":{"@":"underline"}}},"skaBlocksTextDecorationStyle":{"v":{"$":{"@":"solid"}}},"skaBlocksTextDecorationThickness":{"v":{"$":{"@":"6"}}},"skaBlocksTextDecorationColor":{"v":{"$":{"@":"primary/50"}}},"skaBlocksTransitionProperty":{"v":{"$":{"@":"[text-underline-offset]"}},"a":["[text-underline-offset]"]},"skaBlocksAnimation":{"v":{"$":{"@":""},"hover":{"@":"pulse"}}}}},"skaBlocksFontSize":{"v":{"$":{"@":""},"lg":{"@":"5xl"}}}} -->
<h2 class="lg:text-5xl [&_em]:not-italic [&_em]:underline [&_em]:decoration-primary/50 [&_em]:decoration-solid [&_em]:decoration-6 [&_em]:underline-offset-4 [&_em]:hover:underline-offset-8 [&_em]:transition-[text-underline-offset] [&_em]:hover:animate-pulse wp-block-heading"><em>Test</em> heading, <em>please</em> ignore</h2>
<!-- /wp:heading -->Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"lg:text-4xl [\u0026_em]:not-italic [\u0026_em]:font-light [\u0026_em]:tracking-tighter [\u0026_em]:uppercase","css":"@media (min-width:64rem){.lg\\:text-4xl{font-size:var(--text-4xl);line-height:var(--tw-leading,var(--text-4xl--line-height))}}.\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:font-light em{--tw-font-weight:var(--font-weight-light);font-weight:var(--font-weight-light)}.\\[\\\u0026_em\\]\\:tracking-tighter em{--tw-tracking:var(--tracking-tighter);letter-spacing:var(--tracking-tighter)}.\\[\\\u0026_em\\]\\:uppercase em{text-transform:uppercase}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksFontWeight":{"v":{"$":{"@":"light"}}},"skaBlocksLetterSpacing":{"v":{"$":{"@":"tighter"}}},"skaBlocksTextTransform":{"v":{"$":{"@":"uppercase"}}}}},"skaBlocksFontSize":{"v":{"$":{"@":""},"lg":{"@":"4xl"}}}} -->
<h2 class="lg:text-4xl [&_em]:not-italic [&_em]:font-light [&_em]:tracking-tighter [&_em]:uppercase wp-block-heading">Test <em>heading</em>, please ignore</h2>
<!-- /wp:heading -->Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"[\u0026_em]:px-3 lg:text-4xl [\u0026_em]:not-italic [\u0026_em]:tracking-tight [\u0026_em]:text-site-inverted [\u0026_em]:uppercase [\u0026_em]:bg-primary [\u0026_em]:rounded","css":".\\[\\\u0026_em\\]\\:px-3 em{padding-inline:var(--spacing-3)}@media (min-width:64rem){.lg\\:text-4xl{font-size:var(--text-4xl);line-height:var(--tw-leading,var(--text-4xl--line-height))}}.\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:tracking-tight em{--tw-tracking:var(--tracking-tight);letter-spacing:var(--tracking-tight)}.\\[\\\u0026_em\\]\\:text-site-inverted em{color:var(--color-site-inverted)}.\\[\\\u0026_em\\]\\:uppercase em{text-transform:uppercase}.\\[\\\u0026_em\\]\\:bg-primary em{background-color:var(--color-primary)}.\\[\\\u0026_em\\]\\:rounded em{border-radius:var(--radius)}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksTextColor":{"v":{"$":{"@":"site-inverted"}}},"skaBlocksLetterSpacing":{"v":{"$":{"@":"tight"}}},"skaBlocksTextTransform":{"v":{"$":{"@":"uppercase"}}},"skaBlocksBackgroundColor":{"v":{"$":{"@":"primary"}}},"skaBlocksPadding":{"v":{"$":{"@":"","x":"3"}},"t":"axis"},"skaBlocksBorderRadius":{"v":{"$":{"@":"DEFAULT"}}}}},"skaBlocksFontSize":{"v":{"$":{"@":""},"lg":{"@":"4xl"}}}} -->
<h2 class="[&_em]:px-3 lg:text-4xl [&_em]:not-italic [&_em]:tracking-tight [&_em]:text-site-inverted [&_em]:uppercase [&_em]:bg-primary [&_em]:rounded wp-block-heading">Test <em>heading</em>, please ignore</h2>
<!-- /wp:heading -->Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"lg:text-5xl [\u0026_em]:not-italic [\u0026_em]:tracking-tight [\u0026_em]:text-transparent [\u0026_em]:bg-clip-text [\u0026_em]:bg-linear-to-br [\u0026_em]:from-primary/50 [\u0026_em]:via-primary [\u0026_em]:to-pink-500 [\u0026_em]:rounded","css":"@media (min-width:64rem){.lg\\:text-5xl{font-size:var(--text-5xl);line-height:var(--tw-leading,var(--text-5xl--line-height))}}.\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:tracking-tight em{--tw-tracking:var(--tracking-tight);letter-spacing:var(--tracking-tight)}.\\[\\\u0026_em\\]\\:text-transparent em{color:#0000}.\\[\\\u0026_em\\]\\:bg-clip-text em{-webkit-background-clip:text;background-clip:text}.\\[\\\u0026_em\\]\\:bg-linear-to-br em{--tw-gradient-position:to bottom right;background-image:linear-gradient(var(--tw-gradient-stops))}@supports (background-image:linear-gradient(in lab, red, red)){.\\[\\\u0026_em\\]\\:bg-linear-to-br em{--tw-gradient-position:to bottom right in oklab}}.\\[\\\u0026_em\\]\\:from-primary\\/50 em{--tw-gradient-from:#2ba2e580;--tw-gradient-stops:var(--tw-gradient-via-stops,var(--tw-gradient-position),var(--tw-gradient-from)var(--tw-gradient-from-position),var(--tw-gradient-to)var(--tw-gradient-to-position))}@supports (color:color-mix(in lab, red, red)){.\\[\\\u0026_em\\]\\:from-primary\\/50 em{--tw-gradient-from:color-mix(in oklab,var(--color-primary)50%,transparent)}}.\\[\\\u0026_em\\]\\:via-primary em{--tw-gradient-via:var(--color-primary);--tw-gradient-via-stops:var(--tw-gradient-position),var(--tw-gradient-from)var(--tw-gradient-from-position),var(--tw-gradient-via)var(--tw-gradient-via-position),var(--tw-gradient-to)var(--tw-gradient-to-position);--tw-gradient-stops:var(--tw-gradient-via-stops)}.\\[\\\u0026_em\\]\\:to-pink-500 em{--tw-gradient-to:var(--color-pink-500);--tw-gradient-stops:var(--tw-gradient-via-stops,var(--tw-gradient-position),var(--tw-gradient-from)var(--tw-gradient-from-position),var(--tw-gradient-to)var(--tw-gradient-to-position))}.\\[\\\u0026_em\\]\\:rounded em{border-radius:var(--radius)}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksTextColor":{"v":{"$":{"@":"transparent"}}},"skaBlocksLetterSpacing":{"v":{"$":{"@":"tight"}}},"skaBlocksBorderRadius":{"v":{"$":{"@":"DEFAULT"}}},"skaBlocksBackgroundClip":{"v":{"$":{"@":"text"}}},"skaBlocksBackgroundGradient":{"v":{"$":{"@":"","linear":"to-br"}}},"skaBlocksGradientColorStops":{"v":{"$":{"@":"","from":"primary/50","to":"pink-500","via":"primary"}},"t":"default"}}},"skaBlocksFontSize":{"v":{"$":{"@":""},"lg":{"@":"5xl"}}}} -->
<h2 class="lg:text-5xl [&_em]:not-italic [&_em]:tracking-tight [&_em]:text-transparent [&_em]:bg-clip-text [&_em]:bg-linear-to-br [&_em]:from-primary/50 [&_em]:via-primary [&_em]:to-pink-500 [&_em]:rounded wp-block-heading">Test <em>heading</em>, please ignore</h2>
<!-- /wp:heading -->Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"[\u0026_em]:px-3 [\u0026_em]:py-0.5 [\u0026_em]:mr-1.5 lg:text-5xl [\u0026_em]:not-italic [\u0026_em]:rounded-3xl [\u0026_em]:ring-2","css":".\\[\\\u0026_em\\]\\:px-3 em{padding-inline:var(--spacing-3)}.\\[\\\u0026_em\\]\\:py-0\\.5 em{padding-block:var(--spacing-0_5)}.\\[\\\u0026_em\\]\\:mr-1\\.5 em{margin-right:var(--spacing-1_5)}@media (min-width:64rem){.lg\\:text-5xl{font-size:var(--text-5xl);line-height:var(--tw-leading,var(--text-5xl--line-height))}}.\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:rounded-3xl em{border-radius:var(--radius-3xl)}.\\[\\\u0026_em\\]\\:ring-2 em{--tw-ring-shadow:var(--tw-ring-inset,)0 0 0 calc(2px + var(--tw-ring-offset-width))var(--tw-ring-color,currentcolor);box-shadow:var(--tw-inset-shadow),var(--tw-inset-ring-shadow),var(--tw-ring-offset-shadow),var(--tw-ring-shadow),var(--tw-shadow)}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksPadding":{"v":{"$":{"@":"","x":"3","y":"0.5"}},"t":"axis"},"skaBlocksBorderRadius":{"v":{"$":{"@":"3xl"}}},"skaBlocksRingWidth":{"v":{"$":{"@":"2","i":""}}},"skaBlocksMargin":{"v":{"$":{"@":"","r":"1.5"}},"t":"sides"}}},"skaBlocksFontSize":{"v":{"$":{"@":""},"lg":{"@":"5xl"}}}} -->
<h2 class="[&_em]:px-3 [&_em]:py-0.5 [&_em]:mr-1.5 lg:text-5xl [&_em]:not-italic [&_em]:rounded-3xl [&_em]:ring-2 wp-block-heading">Test <em>heading</em>, please ignore</h2>
<!-- /wp:heading -->Test heading, please ignore
<!-- wp:heading {"skaBlocks":{"cx":"[\u0026_em]:isolate [\u0026_em]:relative [\u0026_em]:after:absolute [\u0026_em]:after:inset-0 [\u0026_em]:after:-z-1 [\u0026_em]:px-5 [\u0026_em]:py-1 [\u0026_em]:mr-1.5 [\u0026_em]:after:size-full lg:text-5xl [\u0026_em]:not-italic [\u0026_em]:text-white [\u0026_em]:after:bg-primary [\u0026_em]:after:skew-3","css":".\\[\\\u0026_em\\]\\:isolate em{isolation:isolate}.\\[\\\u0026_em\\]\\:relative em{position:relative}.\\[\\\u0026_em\\]\\:after\\:absolute em:after{content:var(--tw-content);position:absolute}.\\[\\\u0026_em\\]\\:after\\:inset-0 em:after{content:var(--tw-content);inset:var(--spacing-0)}.\\[\\\u0026_em\\]\\:after\\:-z-1 em:after{content:var(--tw-content);z-index:calc(1*-1)}.\\[\\\u0026_em\\]\\:px-5 em{padding-inline:var(--spacing-5)}.\\[\\\u0026_em\\]\\:py-1 em{padding-block:var(--spacing-1)}.\\[\\\u0026_em\\]\\:mr-1\\.5 em{margin-right:var(--spacing-1_5)}.\\[\\\u0026_em\\]\\:after\\:size-full em:after{content:var(--tw-content);width:100%;height:100%}@media (min-width:64rem){.lg\\:text-5xl{font-size:var(--text-5xl);line-height:var(--tw-leading,var(--text-5xl--line-height))}}.\\[\\\u0026_em\\]\\:not-italic em{font-style:normal}.\\[\\\u0026_em\\]\\:text-white em{color:var(--color-white)}.\\[\\\u0026_em\\]\\:after\\:bg-primary em:after{content:var(--tw-content);background-color:var(--color-primary)}.\\[\\\u0026_em\\]\\:after\\:skew-3 em:after{content:var(--tw-content);--tw-skew-x:skewX(3deg);--tw-skew-y:skewY(3deg);transform:var(--tw-rotate-x,)var(--tw-rotate-y,)var(--tw-rotate-z,)var(--tw-skew-x,)var(--tw-skew-y,)}","t":1758876679},"skaBlocksSelectors":{"[\u0026_em]":{"skaBlocksFontStyle":{"v":{"$":{"@":"not-italic"}}},"skaBlocksTextColor":{"v":{"$":{"@":"white"}}},"skaBlocksPadding":{"v":{"$":{"@":"","x":"5","y":"1"}},"t":"axis"},"skaBlocksMargin":{"v":{"$":{"@":"","r":"1.5"}},"t":"sides"},"skaBlocksSelectors":{"after":{"skaBlocksPosition":{"v":{"$":{"@":"absolute"}}},"skaBlocksSize":{"v":{"$":{"@":"full"}}},"skaBlocksTopRightBottomLeft":{"v":{"$":{"@":"","i":"0"}},"t":"inset"},"skaBlocksBackgroundColor":{"v":{"$":{"@":"primary"}}},"skaBlocksSkew":{"v":{"$":{"@":"3"}}},"skaBlocksZIndex":{"v":{"$":{"@":"-1"}}}}},"skaBlocksPosition":{"v":{"$":{"@":"relative"}}},"skaBlocksIsolation":{"v":{"$":{"@":"isolate"}}}}},"skaBlocksFontSize":{"v":{"$":{"@":""},"lg":{"@":"5xl"}}}} -->
<h2 class="[&_em]:isolate [&_em]:relative [&_em]:after:absolute [&_em]:after:inset-0 [&_em]:after:-z-1 [&_em]:px-5 [&_em]:py-1 [&_em]:mr-1.5 [&_em]:after:size-full lg:text-5xl [&_em]:not-italic [&_em]:text-white [&_em]:after:bg-primary [&_em]:after:skew-3 wp-block-heading">Test <em>heading</em>, please ignore</h2>
<!-- /wp:heading -->