Use below shortcodes to change the font size of the text.
Font Size: 0.75rem
<div class="font-small">Your content here..</div><span class="font-small">Your content here..</span><p class="font-small">Your content here..</p>Font Size: 1.25rem
<div class="font-medium">Your content here..</div><span class="font-medium">Your content here..</span><p class="font-medium">Your content here..</p>Font Size: 1.5rem
<div class="font-large">Your content here..</div><span class="font-large">Your content here..</span><p class="font-large">Your content here..</p>Font Size: 2rem
<div class="font-2x">Your content here..</div><span class="font-2x">Your content here..</span><p class="font-2x">Your content here..</p>Font Size: 2.5rem
<div class="font-3x">Your content here..</div><span class="font-3x">Your content here..</span><p class="font-3x">Your content here..</p>Font Size: 3rem
<div class="font-4x">Your content here..</div><span class="font-4x">Your content here..</span><p class="font-4x">Your content here..</p>Font Size: 4rem
<div class="font-5x">Your content here..</div><span class="font-5x">Your content here..</span><p class="font-5x">Your content here..</p>Font Size: 5rem
<div class="font-6x">Your content here..</div><span class="font-6x">Your content here..</span><p class="font-6x">Your content here..</p>Font Size: 6rem
<div class="font-7x">Your content here..</div><span class="font-7x">Your content here..</span><p class="font-7x">Your content here..</p>Font Size: 7rem
<div class="font-8x">Your content here..</div><span class="font-8x">Your content here..</span><p class="font-8x">Your content here..</p>1rem = 16 px
Use <span>some text</span> for inline text.
You can also use Inline Content shortcode for inline content