* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  background: white;
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
  padding: 30px;
  max-width: 1000px;
  width: 90%;
}

.video-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 30px;
  height: 400px;
}

video {
  width: 100%;
  height: 100%;
  border-radius: 15px;
  background: #000;
  object-fit: cover;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

#local-video {
  border: 3px solid #4CAF50;
}

#remote-video {
  border: 3px solid #2196F3;
}

.controls {
  display: flex;
  justify-content: center;
  gap: 15px;
  flex-wrap: wrap;
}

button {
  padding: 15px 25px;
  border: none;
  border-radius: 25px;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  color: white;
  text-transform: uppercase;
  letter-spacing: 1px;
}

#start-btn {
  background: linear-gradient(45deg, #4CAF50, #45a049);
}

#next-btn {
  background: linear-gradient(45deg, #ff9800, #f57c00);
}

#mute-btn {
  background: linear-gradient(45deg, #2196F3, #1976D2);
}

#stop-video-btn {
  background: linear-gradient(45deg, #9C27B0, #7B1FA2);
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

button:disabled {
  background: #cccccc;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

#message {
  text-align: center;
  margin: 20px 0;
  padding: 15px;
  background: linear-gradient(45deg, #f8f9fa, #e9ecef);
  border-radius: 10px;
  font-size: 18px;
  font-weight: 500;
  color: #333;
  border-left: 4px solid #4CAF50;
}

@media (max-width: 768px) {
  .container {
    padding: 20px;
    width: 95%;
  }
  
  .video-container {
    grid-template-columns: 1fr;
    height: auto;
  }
  
  video {
    height: 250px;
  }
  
  .controls {
    gap: 10px;
  }
  
  button {
    padding: 12px 20px;
    font-size: 14px;
  }
}

@media (max-width: 480px) {
  .controls {
    flex-direction: column;
    align-items: center;
  }
  
  button {
    width: 200px;
  }
}