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<html><head><style>h1 { text-decoration-line: underline; text-decoration-thickness: auto; /* this is default */}h2 { text-decoration-line: underline; text-decoration-thickness: 5px;}h3 { text-decoration-line: underline; text-decoration-thickness: 25%;}p { text-decoration-line: underline; text-decoration-color: red; text-decoration-style: double; text-decoration-thickness: 5px; }</style></head><body><h1>Heading 1</h1><h2>Heading 2</h2><h3>Heading 3</h3><p>A paragraph.</p></body></html>