* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: 'Segoe UI', Arial, sans-serif;
  background: linear-gradient(180deg, #87CEEB 0%, #98D8E8 50%, #90EE90 85%, #4A7C23 100%);
  overflow: hidden;
  height: 100vh;
  user-select: none;
}

#gameContainer {
  position: relative;
  width: 100vw;
  height: 100vh;
}

canvas {
  display: block;
}

#ui {
  position: absolute;
  top: 15px;
  left: 15px;
  right: 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
}

.score-panel, .level-panel {
  background: rgba(0, 0, 0, 0.6);
  padding: 10px 20px;
  border-radius: 25px;
  color: white;
  font-size: 18px;
  font-weight: bold;
  backdrop-filter: blur(5px);
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.score-panel span, .level-panel span {
  color: #FFD700;
}

#birdsLeft {
  position: absolute;
  bottom: 15px;
  left: 15px;
  display: flex;
  gap: 10px;
}

.bird-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: #E74C3C;
  border: 3px solid #C0392B;
  cursor: pointer;
  transition: transform 0.2s, opacity 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.bird-icon:hover {
  transform: scale(1.2);
}

.bird-icon.used {
  opacity: 0.3;
  pointer-events: none;
}

#nextBtn {
  position: absolute;
  bottom: 15px;
  right: 15px;
  padding: 12px 30px;
  font-size: 16px;
  font-weight: bold;
  background: linear-gradient(135deg, #27AE60, #2ECC71);
  color: white;
  border: none;
  border-radius: 25px;
  cursor: pointer;
  display: none;
  transition: transform 0.2s, box-shadow 0.2s;
  pointer-events: auto;
}

#nextBtn:hover {
  transform: scale(1.05);
  box-shadow: 0 5px 20px rgba(46, 204, 113, 0.5);
}

#message {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 48px;
  font-weight: bold;
  color: white;
  text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.5);
  display: none;
  text-align: center;
}

#restartBtn {
  position: absolute;
  top: 60%;
  left: 50%;
  transform: translateX(-50%);
  padding: 15px 40px;
  font-size: 20px;
  font-weight: bold;
  background: linear-gradient(135deg, #E74C3C, #C0392B);
  color: white;
  border: none;
  border-radius: 30px;
  cursor: pointer;
  display: none;
  transition: transform 0.2s;
}

#restartBtn:hover {
  transform: translateX(-50%) scale(1.1);
}

#instructions {
  position: absolute;
  bottom: 70px;
  left: 50%;
  transform: translateX(-50%);
  color: white;
  font-size: 16px;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.5);
  pointer-events: none;
}