Code Block Content – coloured background behind text

Hi there
I have created a code block to be able to add a colored background behind the text. however I now want to add the same colored background behind the text “Dowsers Society of NSW Inc.” as well – however I have used a special heading element and changed the font size of the H1 heading to be larger on desktop and a different size on mobile. How can I create the same sizing but with the colored background like the ”
Looking for answers?
Learn to dowse” text?

<div style = “padding: 20px; background: rgba(0,0,0,0.3);”>
<section class=”av_textblock_section av-lvg5hiz5-387748b8bb20df7039517ac6d2cf3547 “>
<div class=”avia_textblock av_inherit_color”>
<h2 style=”text-align: center;”><span style=”color: #ffffff;”>Looking for answers?</span><br>
<span style=”color: #ffffff;”>Learn to dowse</span></h2>
</div>
</section>