Forgot how to change height of gk tabs window on frontpage

I need to set the height of my gk tabs window. Where do I modify this in the css?

It seems to be somewhere around here below. but I cannot discern where to find in .css.

<div class="gk_tab_container0-style1 main" style="height: 520px;">
<div class="gk_tab_container1-style1 clearfix-tabs" style="height: 540px;">
<div class="gk_tab_container2-style1 clearfix-tabs" style="height: 5760px; ">

<div class="gk_tab_item-style1" style="height: 540px; width: 960px; visibility: visible; zoom: 1; opacity: 1; ">