Tom, I looked at the code and both Details All link and the filename are defined by the same style journalHead so your assigned disappearance act gets applied to both.
<div class="journalHead"><p><a target="_self" href="../details.htm#filenamejpg">Details all</a></p></div>
<div class="journalHead"><p>filename.jpg</p></div>
I think there may be a way to turn the Details all back on again if you create another style at the end but I am not sure of the exact syntax - something like ...
.journalHead #a {display: visible;}
The idea is to define the style applied only to an <a> element (using a # selector syntax) that has the journalHead style applied. Sorry I can't take alook into this further, I am actually heading out and will not be available for a couple of weeks. If you still have this issue open when I get back ping me and I'll find out the right syntax, if my assumption is correct.
Or someone else with CSS syntax knowledge may be able to chip in...