List of supported HTML tags in Panorama panels (some may not work in hint text):
Code:
<br>
<i>
<img>
<em>
<p>
<strong>
<li>
<span>
<h1>
<h2>
<font>
<child>
<pre>
<panel>
<a>
<b>
To change font and/or size you can use <span class='XXX'> like SHUFEN mentioned. For a list of valid classes you can use, check the panorama code in code.pbin. The styles available to you in hinttext are found in csgostyles.css and hudhinttext.css.
The most interesting ones are the font size ones, I'll list them here for convenience:
Code:
fontSize-xs - 8px
fontSize-s - 12px
fontSize-sm - 16px
fontSize-m - 18px
fontSize-l - 24px
fontSize-xl - 32px
fontSize-xxl - 40px
fontSize-xxxl - 64px