html,body{
  margin:0; padding:0; height:100%; overflow:hidden; background:#0a1220; color:#fff;
  font-family: system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;
}
#game{ display:block; width:100vw; height:100vh; touch-action:none; }
#hud{ position:fixed; top:0; left:0; right:0; padding:10px 12px; display:flex; justify-content:space-between; align-items:center; z-index:5; }
#score{ font-weight:900; font-size:28px; text-shadow:0 2px 8px rgba(0,0,0,0.5); letter-spacing:0.5px; }
button{ border:none; border-radius:12px; padding:10px 14px; background:#ffffff; color:#0a1220; font-weight:800; box-shadow:0 8px 20px rgba(0,0,0,0.25); }
#overlay{ position:fixed; inset:0; display:flex; flex-direction:column; justify-content:center; align-items:center; gap:12px; background:radial-gradient(1200px 800px at 50% 40%, rgba(0,0,0,0.35), rgba(0,0,0,0.85)); z-index:10; }
#overlay.hidden{ display:none; }
#title{ font-size:32px; font-weight:900; letter-spacing:3px; }
#subtitle{ opacity:0.9; font-size:14px; }
.tips{ opacity:0.8; font-size:12px; }