css chorizo chess board checkers style

sinprepro.css

/*
different types of grids with no formula nor logic styled as a chess board...
all layout logic and colors are handled in css. In html is just

<div class='irServers-XXX'>
  <div class='irServer'>Oh hai</div>
  <div class='irServer'>Oh hai</div>
  <div class='irServer'>Oh hai</div>
  ...
</div>
*/

.irServers>.irServers-0 { background-color: transparent; }
/* 2 row 2 col = 4 cells */
.irServers-4 .irServer { width: 50%; }
/* 2 row 3 col = 6 cells */
.irServers-6 .irServer { width: 33.33%; }
/* 2 row 4 col = 8 cells */
.irServers-8 .irServer { width: 25%; }
/* 3 row 3 col = 9 cells */
.irServers-9 .irServer { width: 33.33%; }
/* 3 row 4 col = 12 cells */
.irServers-12 .irServer { width: 25%; }
/* 4 row 4 col = 16 cells */
.irServers-16 .irServer { width: 25%; }

/* Server colors ... */
.irServers-4 .irServer:nth-child(4n+1),
.irServers-4 .irServer:nth-child(4n),

.irServers-6 .irServer:nth-child(6n+1),
.irServers-6 .irServer:nth-child(6n+3),
.irServers-6 .irServer:nth-child(6n-1),
.irServers-9 .irServer:nth-child(6n+1),
.irServers-9 .irServer:nth-child(6n+3),
.irServers-9 .irServer:nth-child(6n-1),

.irServers-8 .irServer:nth-child(8n+1),
.irServers-8 .irServer:nth-child(8n+3),
.irServers-8 .irServer:nth-child(8n),
.irServers-8 .irServer:nth-child(8n-2),
.irServers-12 .irServer:nth-child(8n+1),
.irServers-12 .irServer:nth-child(8n+3),
.irServers-12 .irServer:nth-child(8n),
.irServers-12 .irServer:nth-child(8n-2),
.irServers-16 .irServer:nth-child(8n+1),
.irServers-16 .irServer:nth-child(8n+3),
.irServers-16 .irServer:nth-child(8n),
.irServers-16 .irServer:nth-child(8n-2),

.omg-wtf-have-i-done {
	background-color: rgb(214, 240, 181);
}