:root {
  --bg: linear-gradient(135deg, #f5f5f5, #e0e0e0);
  --text: #111;
}

body.dark {
  --bg: radial-gradient(circle at top, #1a1a1a, #000);
  --text: #fff;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

/* Glass container */
.container {
  padding: 30px;
  border-radius: 20px;
  text-align: center;

  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(15px);

  box-shadow: 0 10px 40px rgba(0,0,0,0.3);
}

/* Top buttons */
.top-bar button {
  padding: 8px 15px;
  margin: 5px;
  border-radius: 10px;
  border: none;
  cursor: pointer;
}

/* Game grid */
.game {
  display: grid;
  grid-template-columns: repeat(2, 130px);
  gap: 25px;
  margin-top: 20px;
  justify-content: center;
}

/* 3D Buttons */
.btn {
  width: 130px;
  height: 130px;
  border-radius: 25px;
  cursor: pointer;

  box-shadow: 
    0 10px 20px rgba(0,0,0,0.3),
    inset 0 4px 8px rgba(255,255,255,0.2),
    inset 0 -4px 8px rgba(0,0,0,0.4);

  transition: all 0.15s ease;
}

.btn:hover {
  transform: scale(1.05);
}

.btn:active {
  transform: translateY(6px);
  box-shadow: 
    0 4px 10px rgba(0,0,0,0.3);
}

/* Colors */
.red { background: #ff4c4c; }
.yellow { background: #ffd93d; }
.blue { background: #4c6fff; }
.green { background: #4cff88; }

/* Glow flash */
.active {
  transform: scale(1.1);
  filter: brightness(1.5);
  box-shadow:
    0 0 25px white,
    0 0 60px rgba(255,255,255,0.8);
}

/* Score */
.score-board {
  margin-top: 10px;
  display: flex;
  justify-content: space-around;
}

/* Background glow */
body::before {
  content: "";
  position: fixed;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(0,255,255,0.3), transparent);
  top: 10%;
  left: 20%;
  filter: blur(80px);
  z-index: -1;
}