<h1 style="background-color:rgba(255, 99, 71, 0.6);">tiêu đề 1</h1>
<h1 style="background-color:rgba(255, 99, 71, 0.8);">tiêu đề 2</h1>
<h1 style="background-color:rgba(255, 99, 71, 1);">tiêu đề 3</h1>
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