body { font-family: sans-serif; margin: 0 0 0 10ex;}
.a {background-color: white; margin: 0 0.1em}
.a, .h, .v, .hn, .vn {padding: 0; margin: 0; overflow: hidden}
.a {width: 17ex; height: 10ex; font-size: 400%; font-weight: bold; 
    border: 0.1em black solid;}
.v, .vn { height: 50%; width: 100%; font-size: 71%}
.h, .hn { height: 100%; font-size: 71%}
.hn {float: left}
.hn {width: 50%}
.h {width: auto}
.hn {border-right: 0.1em black solid; }
.vn {border-bottom: 0.1em black solid;}
.hn, .vn  {text-align: center}