:root {
  --bg: #050b16;
  --bg-soft: #0d1d31;
  --panel: rgba(12, 19, 32, 0.96);
  --text: #edf6ff;
  --muted: #bdd8ee;
  --green: #22c55e;
  --green-deep: #16a34a;
  --red: #ef4444;
  --red-deep: #dc2626;
  --yellow: #facc15;
  --yellow-deep: #eab308;
  --blue: #3b82f6;
  --blue-deep: #2563eb;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: rgba(2, 6, 23, 0.5);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at top, rgba(59, 130, 246, 0.15), transparent 28%),
    linear-gradient(135deg, var(--bg), var(--bg-soft));
  color: var(--text);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

.game-shell {
  width: min(92vw, 640px);
}

.game-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 28px;
  box-shadow: 0 26px 70px var(--shadow);
  padding: 24px 20px 28px;
}

.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.action-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.label {
  margin: 0;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.72rem;
  font-weight: 700;
}

.exit-btn,
.start-btn {
  border: 0;
  border-radius: 999px;
  font-weight: 800;
  padding: 10px 18px;
  cursor: pointer;
}

.exit-btn {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
}

.start-btn {
  background: linear-gradient(135deg, #f59e0b, #f97316);
  color: white;
}

h1 {
  margin: 18px 0 20px;
  text-align: center;
  font-size: clamp(2.1rem, 4vw, 3rem);
}

.score-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 18px;
  color: var(--muted);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.score-wrap strong {
  font-size: 1.7rem;
  color: var(--text);
}

.board {
  width: min(100%, 360px);
  aspect-ratio: 1;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(2, minmax(130px, 1fr));
  gap: 14px;
}

.pad {
  border: 0;
  border-radius: 22px;
  cursor: pointer;
  transition: transform 0.12s ease, filter 0.12s ease, box-shadow 0.12s ease;
  box-shadow: inset 0 0 0 2px rgba(255,255,255,0.08);
}

.pad:active,
.pad.active {
  transform: scale(0.97);
  filter: brightness(1.25);
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.2);
}

.pad-green {
  background: linear-gradient(135deg, var(--green), var(--green-deep));
}

.pad-red {
  background: linear-gradient(135deg, var(--red), var(--red-deep));
}

.pad-yellow {
  background: linear-gradient(135deg, var(--yellow), var(--yellow-deep));
}

.pad-blue {
  background: linear-gradient(135deg, var(--blue), var(--blue-deep));
}

.message {
  text-align: center;
  min-height: 28px;
  margin: 22px 0 0;
  color: var(--muted);
  font-weight: 600;
}

@media (max-width: 520px) {
  .board {
    grid-template-columns: repeat(2, minmax(100px, 1fr));
  }
}