As a rule of thumb, if it's screwing up in 9, there's something fundamentally flawed with how it's built. Of course, if you have 16 separate CSS files being sent as media="all" and no less than 6 classes on BODY, that goes without saying.
Of course the lack of semantic markup, hordes of endless wrapping DIV for no fathomable reason, pointless wasteful use of title attributes... Ok, lemme guess, is this poopal or turdpress....oop, it's drupal, never would have guessed. Oh wait, yes I did.
The laundry list of problems with the HTML and CSS is far, far too long to even try to get into here; this is NOT a case for a silver bullet fix, this is a case for throwing it out and starting over... since it's 50k of HTML doing 10-15k's job, and a disorganized disaster of multiple CSS files I can't imagine anyone wanting to take the time to even try and debug.
I mean seriously, if this:
<form action="/search/" accept-charset="UTF-8" method="POST" id="views-exposed-form-font-search-page-1"> <div style='display:none'><input type='hidden' name='csrfmiddlewaretoken' value='e539a7059f90caa3220910d478364a9e' /></div>
<div class="views-exposed-widgets clear-block">
<div class="views-exposed-widget views-widget-filter-title">
<div class="form-item" id="edit-title-wrapper">
<input type="text" maxlength="128" name="query" id="edit-title" size="30" value="" class="form-text" />
<div class="views-exposed-widget views-submit-button">
<input type="submit" id="edit-submit-font-search" value="SEARCH" class="form-submit" />
Doesn't set off your "whiskey tango foxtrot" radar...
Bottom line, you've got a laundry list of how NOT to build a website. Chuck it and start over; needs a total reskin which is probably why here the only brower it isn't broken in is Firefox.