Editing collection landing page text in the Website Configuration Tool to include hyperlinks requires the use of the Edit HTML Source button. The <a> element requires separate <span> to define the style as other than default. Example Text might look something like the following:
<p class="cdm_style"><span style="font-size: medium;">This is an example paragraph to demonstrate the following hyperlink: <a href="mailto:support@oclc.org"><span style="font-size: medium;">contact us</span></a>. Now the paragraph can be closed.</span></p>