Channel Entries and Conditionals (For Serious)

{exp:channel:entries channel="portfolio" limit="1" require_entry="yes"} 

 {if portfolio_url == ''}
  Offline
 {if:else}
  
  <a href="{portfolio_url}" title="{title}" target="_blank">
  {portfolio_url}
  </a>
 {/if}

 {if portfolio_challenges != ''}
 <p><strong>Challenges:</strong><br />
  {portfolio_challenges}
 </p>
 {/if}

{/exp:channel:entries}