CSS in custom.css not showing up on website

I’ve relatively recently updated the enfold theme to version 3.5.4 and have seemed to be getting problems since then.
The custom.css file no longer seems to respond to input/alterations. WordPress does allow me to enter css into the quick css area of the enfold theme and that does show style changes up for a while however it can be prone to just breaking for no reason with the previous style entered being set and no css alteration being able to change it without wiping the site and building again.
Here is the css for my site, it was working before the update so maybe alterations are needed.

.html_header_top.html_logo_center .logo{ left:0%;
-webkit-transform: translate(0%, 0);
-ms-transform: translate(0%, 0);
transform: translate(0%, 0);
}
.avia-msie-8.html_header_top.html_logo_center .logo { left:0%;}

.header_color .main_menu ul:first-child > li > a { color: #ffffff; font-weight: normal; font-size: 30px;}
.header_color .main_menu ul:first-child > li a:hover { color: #ffffff; font-weight: bold; font-size: 30px;}
.header_color .main_menu ul:first-child > li.current_page_item > a { color: #D9D9D9; font-weight: bold; font-size: 30px;}
.header_color .main_menu ul > li {padding-left: 20px; padding-right: 20px;}

.header_color .main_menu ul > li:nth-child(1) > a {background: #9E9D9D;}
.header_color .main_menu ul > li:nth-child(2) > a {background: #9AABBA;}
.header_color .main_menu ul > li:nth-child(3) > a {background: #8D7263;}
.header_color .main_menu ul > li:nth-child(4) > a {background: #FF9955;}
.header_color .main_menu ul > li:nth-child(5) > a {background: #DC27F4;}
li {white-space: nowrap;}

switchWidth = 950;