html, body {
      margin: 0; padding: 0; overflow: hidden;
      background: #000;
      user-select: none; -webkit-user-select: none;
 
}


    #game-container {
      position: relative;
      width: 100vw; height: 85vh;
    }
    canvas {
      display: block;
      width: 100%; height: 100%;
      background: #0c0f40;
    }
    .control {
      position: absolute;
      width: 60px;
      height: 260px;  /* 上下ボタン各120px + 間20px */
      display: flex; flex-direction: column;
      justify-content: space-between;
      pointer-events: auto;
    }
    #p1-controls { left: 5px;  top: 50%; transform: translateY(-50%); }
    #p2-controls { right: 5px; top: 50%; transform: translateY(-50%); }
    .control button {
      width: 100%; height: 120px;
      background: #222; color: #fff;
      font-size: 18px;
      border: none; outline: none;
      touch-action: none;
      user-select: none; -webkit-user-select: none;
    }
    #overlay {
      position: absolute; top: 0; left: 0;
      width: 100%; height: 100%;
      background: rgba(0,0,0,0.8);
      color: #fff; font-size: 28px;
      display: flex; flex-direction: column;
      justify-content: center; align-items: center;
      text-align: center; white-space: pre-line;
      visibility: hidden; pointer-events: auto;
      padding: 0 20px;
    }