* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #0f1720;
  --panel: #11121a;
  --accent: #22c55e;
  --muted: #9aa4b2;
  --card-border: rgba(255,255,255,0.04);
}

body {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background: linear-gradient(180deg, #071021 0%, #0f1720 100%);
  color: #e6eef6;
  padding: 20px;
}

.container {
  width: 100%;
  max-width: 640px;
  text-align: center;
}

h1 { font-size: 1.9rem; margin-bottom: 6px; }
p { margin: 8px 0; color: var(--muted); }

.controls {
  display: flex;
  gap: 12px;
  justify-content: center;
  align-items: center;
  margin-bottom: 12px;
  flex-wrap: wrap;
}

button {
  background: var(--accent);
  color: #022;
  border: none;
  padding: 10px 16px;
  border-radius: 10px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(34,197,94,0.12);
}
button:hover { transform: translateY(-2px); }

.info {
  display: flex;
  gap: 12px;
  align-items: center;
  font-weight: 600;
  color: #fff;
}

.game-area {
  margin: 0 auto;
  width: 100%;
  height: 360px;
  max-height: 60vh;
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border-radius: 12px;
  border: 1px solid var(--card-border);
  position: relative;
  overflow: hidden;
  box-shadow: 0 8px 30px rgba(2,6,23,0.6);
}

/* Circle */
.circle {
  position: absolute;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  user-select: none;
  transition: transform 0.12s linear, opacity 0.12s linear;
  will-change: transform, opacity;
}

/* Target label & sample */
#targetLabel {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  font-weight: 700;
  color: #fff;
}
.target-sample {
  display: inline-block;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  margin-left: 8px;
  vertical-align: middle;
  border: 2px solid rgba(255,255,255,0.08);
}

/* Result */
.result-box {
  margin-top: 14px;
  padding: 14px;
  border-radius: 10px;
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--card-border);
}

.hidden { display: none; }

.hint {
  margin-top: 10px;
  font-size: 0.9rem