* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: radial-gradient(circle at top, #05334d, #02111a 70%);
  color: #e0f2fe;
}
.wrap { max-width: 560px; margin: 0 auto; padding: 16px; }
.topnav { margin-bottom: 10px; color: #bae6fd; }
.topnav a { color: #e0f2fe; text-decoration: none; }
.topnav a:hover { text-decoration: underline; }
h1 { margin: 6px 0 4px; }
.subtitle { margin: 0 0 12px; color: #bae6fd; }
.hud {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 12px;
}
.hud > div {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.16);
  border-radius: 10px;
  padding: 8px;
  text-align: center;
}
.arena {
  position: relative;
  width: 100%;
  aspect-ratio: 1.2 / 1;
  border-radius: 14px;
  border: 1px solid rgba(255,255,255,0.2);
  background: linear-gradient(180deg, #082f49, #0c4a6e);
  overflow: hidden;
}
.target {
  position: absolute;
  width: 56px;
  height: 56px;
  border-radius: 999px;
  border: 0;
  background: #fef08a;
  color: #fef08a;
  cursor: pointer;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 0 6px rgba(254,240,138,0.25);
}
.controls { margin-top: 12px; display: grid; gap: 8px; }
button#startBtn {
  background: #0284c7;
  color: white;
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 1rem;
  cursor: pointer;
}
button#startBtn:hover { background: #0369a1; }
.msg { margin: 0; color: #bae6fd; min-height: 1.2rem; }