WDCSS - Triple Boxes, Expanding

<div class="b3la"><div class="bh">
First Header Here
</div><div class="cntnt">
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<p>This is a paragraph. Feel free to add more content. Remember to wrap chunks of text in paragraphs.</p>
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</div></div><div class="b3ma"><div class="bh">
Second Header Here
</div><div class="cntnt">
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<p>This is a paragraph. Feel free to add more content. Remember to wrap chunks of text in paragraphs.</p>
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</div></div><div class="b3ra"><div class="bh">
Third Header Here
</div><div class="cntnt">
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<p>This is a paragraph. Feel free to add more content. Remember to wrap chunks of text in paragraphs.</p>
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