This will do it:
ul.gf-menu li.item176 .dropdown {
left: -300px !important;
}
But, you'll have to use that inside media queries as the position will change as the viewport gets smaller./* Smartphones */
@media (max-width: 480px) {
}
/* Smartphones to Tablets */
@media (min-width: 481px) and (max-width: 767px) {
}
/* Tablets */
@media (min-width: 768px) and (max-width: 959px) {
}
/* Desktop */
@media (min-width: 960px) and (max-width: 1199px) {
}
/* Large Display */
@media (min-width: 1200px) {
}
You also have plenty of other issues too as you are using a responsive template (e.g. menu crashing through logo at smaller display sizes).
You also appear to be using "progressive caching" - do not use this - instead use "conservative" and clear server cache after changing.
This is how to create a custom CSS compatible with Gantry 4...
Simply create a file called "<TEMPLATENAME>-custom.css" and put this file in the CSS folder of the template (where <TEMPLATENAME> is the name of the template as seen in template manager e.g. rt_fracture). GANTRY4 will automatically load this CSS file. If you wish, you can also have browser specific files by appending, for example, "-ie9" making the filename "<TEMPLATENAME>-custom-ie9.css"
For more information on debugging & customising with LESS/CSS please read this blog post
http://www.rockettheme.com/blog/coding/1767-basics-debugging-a-customizing-with-lesscss
.
Regards, Mark.