This is missing in index.css; approximately line 335
.grid10 {
width: 10%;
}
This is missing in index.css; approximately line 98
.grid10,
Line 98 goodies should look like this.
/* Declarations for specific elements. @todo - Maybe simplify - test. */
.wrapper, div.windowbg, div.windowbg2,
.roundframe, .description, .information, .successbox, .warningbox,
.category_header, .generic_list_wrapper, .submitbutton, .grid10,
.grid8, .grid17, .grid20, .grid25, .grid30, .grid33, .grid50, #description_board .generalinfo {
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
box-sizing: border-box;
}
.grid10 is used in ManagePermissions.controller.php on lines 228 and 364.
Attached images show dispaly of Permissions>General Permissions, Regular groups with the missing .grid10, with the .grid10 implemented and finally with the other grids for that table being converted to grid17; except for the input box. I think it looks better with all grid17 but that is purely subjective.
ETA.... variant is the Light variant using sidebar menus.