body { font-family: sans-serif; margin: 0; }
.landing { max-width: 30em; margin: 3em auto; padding: 0 1em; }
.error { color: #b00020; }
body.game { display: flex; flex-direction: column; height: 100vh; }
#panes { display: flex; flex: 1; min-height: 0; }
#panes[hidden] { display: none; }
#panes iframe { flex: 1; border: 0; width: 50%; }
#waiting { flex: 1; padding: 1em; }
#waiting[hidden] { display: none; }
form.end { padding: 0.5em; }