:root {
  --bg-color: #1A1400;
  --primary-color: #F39C12;
  --secondary-color: #F1C40F;
  --accent-color: #E74C3C;
  --text-color: #ECF0F1;
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --font-family: 'Inter', system-ui, sans-serif;
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-family);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  overflow: hidden;
}

#app {
  display: flex;
  gap: 2rem;
  padding: 2rem;
  background: radial-gradient(circle at top right, rgba(243, 156, 18, 0.1), transparent 40%);
}

.game-container {
  position: relative;
  border-radius: 12px;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
  border: 1px solid var(--glass-border);
  overflow: hidden;
}

canvas#game-board {
  display: block;
  background-color: #000;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  min-width: 200px;
}

.panel {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
}

.panel h2 {
  margin: 0 0 0.5rem 0;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--secondary-color);
}

.value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
}

#next-piece {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 120px;
}

canvas#next-canvas {
  /* background: transparent; */
}

.controls-info {
  font-size: 0.8rem;
  color: #bdc3c7;
  text-align: left;
}
.controls-info div {
  margin-bottom: 0.5rem;
}
.key {
  display: inline-block;
  padding: 2px 6px;
  background: rgba(255,255,255,0.1);
  border-radius: 4px;
  font-family: monospace;
  margin-right: 5px;
  color: var(--secondary-color);
}

#overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(5px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 10;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

#overlay.visible {
  opacity: 1;
  pointer-events: all;
}

#overlay h1 {
  font-size: 3rem;
  color: var(--accent-color);
  margin-bottom: 1rem;
  text-shadow: 0 0 10px var(--accent-color);
}

#overlay p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

button.btn-primary {
  background: var(--primary-color);
  color: #fff;
  border: none;
  padding: 0.8rem 2rem;
  font-size: 1.2rem;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.1s;
  font-weight: bold;
}

button.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(243, 156, 18, 0.4);
}

button.btn-primary:active {
  transform: translateY(0);
}

@media (max-width: 600px) {
  #app {
    flex-direction: column;
    padding: 1rem;
    gap: 1rem;
    align-items: center;
  }

  .sidebar {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    min-width: unset;
    width: 100%;
  }

  .panel {
    flex: 1;
    min-width: 100px;
    padding: 0.5rem;
  }

  #next-piece {
    display: none; /* Hide next piece on very small screens to save space? Or keep it. */
  }
}