Should I use style.css or Simple Custom CSS?

Hi!

I'm running multisite, and I usually want the CSS changes I make to be applied across all the network. So, should I insert code in style.css or in Simple Custom CSS?

I also use WPMU New Blog Templates, and I've ran into some issues regarding code that was inserted in Custom CSS at wp admin, but wasn't being applied to subsites, so I had to insert the same code in the Custom CSS of the template account in Blog Templates.

Here's what I have at style.css:

/*
 Theme Name:   PRO3 Child
 Theme URI:    http://marketpressthemes.com
 Description:  PRO3 Child Theme
 Author:       Nathan Onn (MarketPressThemes.com)
 Author URI:   http://marketpressthemes.com
 Template:     pro3
 Version:      3.4
 Tags:         blue, red, black, yellow, green, right-sidebar, fixed-width, flexible-width, custom-colors, custom-header, custom-menu, editor-style, featured-images, full-width-template, theme-options
 Text Domain:  pro3-child
*/

@import url("../pro3/style.css");

/* =Theme customization starts here
-------------------------------------------------------------- */

#tt_mp_fe_content.tt_mp_fe #sidebar a,
#tt_mp_fe_content.tt_mp_fe input,
#tt_mp_fe_content.tt_mp_fe select,
#tt_mp_fe_content.tt_mp_fe p,
#tt_mp_fe_content.tt_mp_fe label,
#tt_mp_fe_content.tt_mp_fe .widefat th {
    font-size: 16px;
}

#tt_mp_fe_content.tt_mp_fe .submitbox .submitdelete,
#tt_mp_fe_content #mp_upload_button,
#tt_mp_fe_content.tt_mp_fe #set-post-thumbnail,
#tt_mp_fe_content.tt_mp_fe .submit input,
#tt_mp_fe_content.tt_mp_fe .button,
#tt_mp_fe_content.tt_mp_fe input.button,
#tt_mp_fe_content.tt_mp_fe .button-primary,
#tt_mp_fe_content.tt_mp_fe input.button-primary,
#tt_mp_fe_content.tt_mp_fe .button-secondary,
#tt_mp_fe_content.tt_mp_fe input.button-secondary,
#tt_mp_fe_content.tt_mp_fe .button-highlighted,
#tt_mp_fe_content.tt_mp_fe input.button-highlighted,
#tt_mp_fe_content.tt_mp_fe #postcustomstuff .submit input {font-size: 12px !important;}

#tt_mp_fe_content small {font-size: 16px;}

#tt_mp_fe_content.tt_mp_fe a {font-size: 16px;}

#ui-datepicker-div {display: none;}

Here's what I have at the Custom CSS of wp admin:

.oneall_social_login {
height: 65px;
overflow: hidden;
}

.page-id-393 #sidebar {display:none;}
.page-id-393 .row-fluid .span8 {width:100%;}

.page-id-393 .row-fluid .span8 .page-heading h1 {font-family:Museo Sans Rounded; text-align:center;}

#tt_mp_fe_content .postwrap .entry2 > div > img {display: none;}

.tt_mp_fe #sidebar,
.tt_mp_fe  {
    padding: 0 !important;
}

.post-393 code {
border: none;
background: none;
}

#buddypress .standard-form label, #buddypress .standard-form span.label {white-space:normal;}

#buddypress .standard-form #basic-details-section, #buddypress .standard-form #blog-details-section, #buddypress .standard-form #profile-details-section {margin-top:40px;}

#blogs-dir-list .pagination {
float: none !important;
}

#buddypress div.pagination {
float: none !important;
}

.wpcr_power, #wpcr_hcard_s {
display: none;
}

.store-admin-button{float:left;}
.blog-button{float:right; margin-left:5px}

body {
-ms-overflow-style: scrollbar !important;
}

.profile p:only-of-type{
  display:none;
}

#avatar-upload input{
background: #fff !important;
border: 1px solid #ccc !important;
color: #777 !important;
cursor: pointer !important;
padding: 4px 10px !important;
text-align: center !important;
text-decoration: none !important;
}

#avatar-upload input:nth-of-type(2){
height: 40px;
}

#blog-dir-search label {
display: inline !important;
}

#buddypress div.dir-search {
margin: 0 auto 0 0px !important;
position: relative;
}

#buddypress div.dir-search input[type="text"] {
padding: 3px !important;
}

#buddypress div#subnav.item-list-tabs {
width 35%;
margin: 0 auto;
}

#buddypress input#blogs_search {
margin-bottom: 0px;
}

#blog-dir-count-bottom {
float; right;
}

.jcrop-holder {
overflow-y: scroll;
max-width: 450px;
max-height: 220px !important;
}

/*This should be added to your child-theme so it applies to all sites using the theme*/
#header-wrapper ul, #header-wrapper ol {
  list-style:none;
}

And here's what I have in the Custom CSS at the template account from Blog Templates:

#sidebar ul li:before {
background-image: none;
}

.sidebar-widget-well .mp_store_navigation li:nth-child(2) {display:none;}
.sidebar-widget-well .mp_store_navigation li {background-position: 0px 8px}
.sidebar-widget-well .mp_store_navigation li:before {background:none!important;}

#tt_mp_fe_content .postwrap .entry2 > div > img {display: none;}

.tt_mp_fe #sidebar,
.tt_mp_fe  {
    padding: 0 !important;
}

So, should I remove all repeated code and insert everything in style.css? Considering the codes I've mentioned, could that procedure cause me any issues?

Thanks.