body {
		  margin: 0;
		  overflow: hidden;
		  background-color: black;
		}
		
		.scene {
		  width: 100%;
		  height: 100%;
		  position: fixed;
		  top: 0;
		  left: 0;
      display: none;
		}
		
		.credits {
		  position: fixed;
		  bottom: 20px;
		  left: 50%;
		  transform: translateX(-50%);
		  z-index: 10;
		  text-align: center;
		}
		
		.countdown-btn {
		  background: linear-gradient(135deg, #EE4250 0%, #C3373E 50%, #BC2926 100%);
		  border: none;
		  border-radius: 50px;
		  padding: 15px 40px;
		  cursor: pointer;
		  box-shadow: 0 8px 25px rgba(238, 66, 80, 0.4), 0 4px 10px rgba(0, 0, 0, 0.3);
		  transition: all 0.3s ease;
		  animation: glow 2s ease-in-out infinite;
		}
		
		.countdown-btn:hover {
		  transform: scale(1.05);
		  box-shadow: 0 12px 35px rgba(238, 66, 80, 0.6), 0 6px 15px rgba(0, 0, 0, 0.4);
		}
		
		.countdown-btn a {
		  display: inline-block;
		  padding: 0;
		  color: #fff;
		  text-decoration: none;
		  font-family: 'Helvetica Neue', Helvetica, Verdana, sans-serif;
		  font-size: 18px;
		  font-weight: bold;
		  letter-spacing: 1px;
		  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
		}
		
		.countdown-btn:hover a {
		  text-decoration: none;
		}
		
		@keyframes glow {
		  0%, 100% {
		    box-shadow: 0 8px 25px rgba(238, 66, 80, 0.4), 0 4px 10px rgba(0, 0, 0, 0.3);
		  }
		  50% {
		    box-shadow: 0 8px 35px rgba(238, 66, 80, 0.7), 0 4px 15px rgba(0, 0, 0, 0.4), 0 0 20px rgba(255, 215, 0, 0.3);
		  }
		}
		
		a {
		  display: block;
		  padding: 2px 0;
		  color: #1d1f3f;
		  text-decoration: none;
		  font-family: Helvetica, Verdana, sans-serif;
		  font-size: 15px;
		}
		
		a:hover {
		  text-decoration: underline;
		}
		
		.gift.hidden {
		  display: none;
		}
		
		.gift {
		  position: fixed;
		  top: 0;
		  left: 0;
		  width: 100%;
		  height: 100%;
		  background: black;
		  cursor: pointer;
		}
		
		.gift svg {
		  width: 100%;
		  height: 100%;
		}

/* Mobile responsive styles */
@media screen and (max-width: 768px) {
  .countdown-btn {
    padding: 12px 25px;
  }
  
  .countdown-btn a {
    font-size: 14px;
    letter-spacing: 0.5px;
  }
  
  .credits {
    bottom: 15px;
    width: 90%;
    max-width: 300px;
  }
}

@media screen and (max-width: 480px) {
  .countdown-btn {
    padding: 10px 20px;
  }
  
  .countdown-btn a {
    font-size: 12px;
  }
  
  .credits {
    bottom: 10px;
  }
}

/* Force landscape orientation hint for very small portrait screens */
@media screen and (max-width: 480px) and (orientation: portrait) and (max-height: 700px) {
  body::before {
    content: '📱 Xoay ngang màn hình để xem tốt hơn';
    position: fixed;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 12px;
    font-family: 'Helvetica Neue', Helvetica, sans-serif;
    z-index: 1000;
    white-space: nowrap;
    animation: fadeInOut 5s ease-in-out forwards;
  }
}

@keyframes fadeInOut {
  0% { opacity: 0; }
  10% { opacity: 1; }
  80% { opacity: 1; }
  100% { opacity: 0; visibility: hidden; }
}