.c4-wrapper {
  width: 100%; height: 100%; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, rgba(10,10,15,0.95), rgba(20,10,30,0.95));
  font-family: 'Courier New', monospace; overflow: auto; padding: 20px;
}
.c4-container {
  background: rgba(30,20,40,0.6); backdrop-filter: blur(20px);
  border: 1px solid rgba(255,0,60,0.3); border-radius: 20px; padding: 30px;
  box-shadow: 0 8px 32px rgba(255,0,60,0.2), inset 0 1px 0 rgba(255,255,255,0.1);
  max-width: 600px; width: 100%;
}
.c4-title {
  text-align: center; color: #ff003c; font-size: 28px; margin: 0 0 15px;
  text-shadow: 0 0 20px rgba(255,0,60,0.8), 0 0 40px rgba(255,0,60,0.4); letter-spacing: 6px;
}
.c4-hud { display: flex; justify-content: space-around; margin-bottom: 15px; font-size: 13px; }
.c4-stat { color: #ff4488; text-shadow: 0 0 10px rgba(255,68,136,0.6); }
.c4-turn {
  text-align: center; color: #00ff88; font-size: 16px; margin-bottom: 15px;
  text-shadow: 0 0 10px rgba(0,255,136,0.6); letter-spacing: 2px; font-weight: bold;
}
.c4-board {
  display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px;
  background: rgba(20,15,30,0.9); padding: 10px; border-radius: 12px;
  border: 2px solid rgba(255,0,60,0.4); box-shadow: 0 0 30px rgba(255,0,60,0.3);
  margin-bottom: 20px; max-width: 500px; margin-left: auto; margin-right: auto;
}
.c4-cell {
  aspect-ratio: 1; background: rgba(10,8,20,0.9); border-radius: 50%;
  border: 2px solid rgba(100,80,120,0.4); cursor: pointer; transition: all 0.3s;
}
.c4-cell:hover { border-color: rgba(255,0,60,0.8); box-shadow: 0 0 15px rgba(255,0,60,0.4); }
.c4-cell.player1 {
  background: radial-gradient(circle, #00ff88, #00aa55); border-color: #00ff88;
  box-shadow: 0 0 20px rgba(0,255,136,0.8), inset 0 0 10px rgba(255,255,255,0.3);
}
.c4-cell.player2 {
  background: radial-gradient(circle, #ff003c, #aa0028); border-color: #ff003c;
  box-shadow: 0 0 20px rgba(255,0,60,0.8), inset 0 0 10px rgba(255,255,255,0.3);
}
.c4-message {
  text-align: center; color: #ffff00; font-size: 20px; font-weight: bold;
  text-shadow: 0 0 15px rgba(255,255,0,0.8); min-height: 28px; margin-bottom: 15px;
}
.c4-btn {
  display: block; margin: 0 auto; padding: 12px 30px; background: rgba(255,0,60,0.2);
  border: 2px solid #ff003c; border-radius: 8px; color: #ff003c;
  font-family: 'Courier New', monospace; font-size: 14px; font-weight: bold; cursor: pointer;
  letter-spacing: 2px; text-shadow: 0 0 10px rgba(255,0,60,0.8);
  box-shadow: 0 4px 15px rgba(255,0,60,0.3); transition: all 0.3s;
}
.c4-btn:hover {
  background: rgba(255,0,60,0.4); box-shadow: 0 6px 25px rgba(255,0,60,0.5);
  transform: translateY(-2px);
}