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

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

#game-container {
  position: relative;
  width: 800px;
  max-width: 95vw;
  aspect-ratio: 16/9;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  border-radius: 8px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

#start-screen, #game-over {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background: rgba(0, 0, 0, 0.85);
  border-radius: 8px;
  color: white;
  text-align: center;
}

#start-screen h1 {
  font-size: 3rem;
  margin-bottom: 1rem;
  background: linear-gradient(45deg, #ff6b6b, #feca57, #48dbfb, #ff9ff3);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient 3s ease infinite;
  background-size: 300% 300%;
}

@keyframes gradient {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

#start-screen p, #game-over p {
  font-size: 1.2rem;
  margin: 0.5rem 0;
  opacity: 0.9;
}

button {
  margin-top: 1.5rem;
  padding: 1rem 2.5rem;
  font-size: 1.2rem;
  font-weight: bold;
  color: white;
  background: linear-gradient(45deg, #667eea, #764ba2);
  border: none;
  border-radius: 50px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6);
}

button:active {
  transform: translateY(0);
}

#hud {
  position: absolute;
  top: 10px;
  left: 10px;
  right: 10px;
  display: flex;
  justify-content: space-between;
  pointer-events: none;
  color: white;
  font-weight: bold;
  font-size: 1.2rem;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.hidden {
  display: none !important;
}

#game-over h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #ff6b6b;
}

#high-score {
  color: #feca57;
  font-weight: bold;
  margin-top: 1rem;
}

@media (max-width: 600px) {
  #start-screen h1 {
    font-size: 2rem;
  }

  #game-over h2 {
    font-size: 2rem;
  }

  button {
    padding: 0.8rem 2rem;
    font-size: 1rem;
  }

  #hud {
    font-size: 1rem;
  }
}