#game-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
}

#game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background: rgba(0,0,0,0.5);
    flex-shrink: 0;
}

.back-btn {
    color: #fff;
    text-decoration: none;
    padding: 0.5rem 1rem;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
}

.game-info {
    display: flex;
    gap: 1rem;
    font-size: 0.9rem;
}

#game-canvas {
    flex: 1;
    width: 100%;
    background: #0a0a0a;
    touch-action: none;
}

#tower-panel {
    background: rgba(0,0,0,0.8);
    padding: 0.75rem;
    flex-shrink: 0;
}

#tower-panel h3 {
    font-size: 0.85rem;
    margin-bottom: 0.5rem;
    color: #aaa;
}

.tower-options {
    display: flex;
    gap: 0.5rem;
    overflow-x: auto;
    padding-bottom: 0.25rem;
}

.tower-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: rgba(255,255,255,0.1);
  border: 2px solid transparent;
  border-radius: 12px;
  padding: 0.5rem;
  min-width: 70px;
  color: #fff;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.tower-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.2), transparent);
  opacity: 0;
  transition: opacity 0.2s;
}

.tower-btn:hover::before {
  opacity: 1;
}

.tower-btn.selected {
  border-color: #ff6b6b;
  background: rgba(255,107,107,0.2);
  box-shadow: 0 0 15px rgba(255,107,107,0.4);
}

.tower-btn:disabled {
  opacity: 0.4;
  filter: grayscale(30%);
}

.tower-icon {
  font-size: 1.8rem;
  text-shadow: 0 0 10px currentColor;
}

.tower-name {
  font-size: 0.8rem;
  margin: 0.25rem 0;
  font-weight: 600;
}

.tower-cost {
  font-size: 0.7rem;
  color: #feca57;
  font-weight: bold;
}

#controls {
    display: flex;
    gap: 0.5rem;
    padding: 0.75rem;
    background: rgba(0,0,0,0.5);
    flex-shrink: 0;
}

#start-wave {
    flex: 1;
    padding: 1rem;
    background: linear-gradient(135deg, #ff6b6b, #ee5a24);
    border: none;
    border-radius: 12px;
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}

#speed-btn {
    padding: 1rem 1.5rem;
    background: rgba(255,255,255,0.1);
    border: none;
    border-radius: 12px;
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}

#game-over {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

#game-over.hidden {
    display: none;
}

#game-over h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

#game-over p {
    margin-bottom: 1.5rem;
    color: #aaa;
}

#restart-btn {
  padding: 1rem 2rem;
  background: #ff6b6b;
  border: none;
  border-radius: 12px;
  color: #fff;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
}

#upgrade-panel {
  background: rgba(0,0,0,0.8);
  padding: 0.75rem;
  border-top: 1px solid rgba(255,255,255,0.1);
}

#upgrade-panel.hidden {
  display: none;
}

#upgrade-panel h3 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: #feca57;
}

#upgrade-panel p {
  font-size: 0.8rem;
  color: #aaa;
  margin: 0.25rem 0;
}

#upgrade-btn {
  margin-top: 0.5rem;
  padding: 0.5rem 1rem;
  background: linear-gradient(135deg, #feca57, #f39c12);
  border: none;
  border-radius: 8px;
  color: #000;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

#upgrade-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#map-select {
  display: flex;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(0,0,0,0.3);
}

.map-btn {
  padding: 0.5rem 1rem;
  background: rgba(255,255,255,0.1);
  border: 2px solid transparent;
  border-radius: 8px;
  color: #fff;
  font-size: 0.8rem;
  cursor: pointer;
}

.map-btn.selected {
  border-color: #feca57;
  background: rgba(254,202,87,0.2);
}