body{margin:0;background:#000;color:#fff;font-family:sans-serif;overflow:hidden}
video{position:fixed;inset:0;width:100%;height:100%;object-fit:cover}
.center{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center}
.arenas button,#begin{margin:6px;padding:10px 18px;border-radius:20px;border:none;cursor:pointer}
canvas{position:fixed;inset:0}
.hidden{display:none}
.modal{position:fixed;inset:0;display:flex;align-items:center;justify-content:center;background:rgba(0,0,0,.6)}
.card{background:rgba(0,0,0,.8);padding:24px;border-radius:20px;max-width:400px}
.orb{width:220px;height:220px;border-radius:50%;background:radial-gradient(circle,gold,rgba(255,215,0,.2));animation:breathe 12s ease-in-out infinite}
@keyframes breathe{0%{transform:scale(.9)}50%{transform:scale(1.1)}100%{transform:scale(.9)}}