/* =========================================
   BACKGROUND – SYNTHWAVE GRADIENT
   ========================================= */
#bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;

  background: radial-gradient(circle at center,
      #240042 0%,
      #130028 40%,
      #060014 70%,
      #000000 100%);
  
  animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
  0%   { filter: brightness(0.95); }
  50%  { filter: brightness(1.10); }
  100% { filter: brightness(0.95); }
}

/* =========================================
   GLOBAL
   ========================================= */
html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: #000;
  overflow: hidden;
  touch-action: none;
  -webkit-user-select: none;
  user-select: none;
}

/* =========================================
   CANVAS
   ========================================= */
#gameCanvas {
  position: fixed;
  inset: 0;
  margin: auto;
  z-index: 10;
  display: block;
  image-rendering: pixelated;
}

/* =========================================
   MENU OVERLAY
   ========================================= */
#snakeMenu {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.85);
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.25s ease;
    z-index: 9999;
}

.menu-container {
    text-align: center;
    font-family: monospace;
    color: #fff;
}

.menu-title {
    font-size: 48px;
    margin-bottom: 30px;
    letter-spacing: 4px;
}

.menu-btn {
    display: block;
    width: 260px;
    margin: 12px auto;
    padding: 14px 0;
    font-size: 20px;
    border: 2px solid #fff;
    background: transparent;
    color: #fff;
    border-radius: 6px;
    cursor: pointer;
    transition: 0.2s;
}

.menu-btn:hover {
    background: #fff;
    color: #000;
}

.menu-small {
    margin-top: 32px;
    opacity: 0.5;
}

.mode-desc {
    display: block;
    font-size: 10px;
    opacity: 0.6;
    margin-top: 4px;
}

.menu-controls {
    margin-top: 20px;
    font-size: 12px;
    opacity: 0.4;
}

.menu-btn.selected {
    border-color: #00fff0;
    color: #00fff0;
    box-shadow: 0 0 20px rgba(0, 255, 240, 0.3);
}