#rq{width: 100vw;height: 100vh;background:;}

#rq_z{width: 50vw;height: calc(100vh - 40px);background:;float:left;}
#rq_y{width: 50vw;height: calc(100vh - 40px);background:;float:left;}

#rq50{width: 50vw;float:left;}

#rq_z_a{width: 25vw;float:left;}
#rq_z_b{width: 25vw;float:left;}

#chenna1,#chenna2,#chenna3,#chenna4,#chenna5,#chenna6,#chenna7{width: 50vw;float:left;}