* {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      user-select: none;
    }
    body {
      background: #0d0a1a;
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      overflow: hidden;
      height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    #game-container {
      position: relative;
      width: 100vw;
      height: 100vh;
      max-width: 500px;
      max-height: 850px;
      background: linear-gradient(to bottom, #0a0814, #1a1532, #382042);
      box-shadow: 0 10px 40px rgba(0,0,0,0.6);
      border-radius: 16px;
      overflow: hidden;
    }
    canvas {
      display: block;
      width: 100%;
      height: 100%;
    }
    #ui {
      position: absolute;
      top: 18px;
      left: 0;
      width: 100%;
      padding: 0 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: #ffe3ec;
      font-weight: 600;
      font-size: 1rem;
      text-shadow: 0 2px 5px rgba(0,0,0,0.6);
      z-index: 10;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s ease;
    }
    #ui.active {
      opacity: 1;
      pointer-events: auto;
    }
    .exit-btn {
      background: rgba(255, 255, 255, 0.15);
      border: 1px solid rgba(255, 255, 255, 0.3);
      color: #ffe3ec;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 0.85rem;
      font-weight: bold;
      cursor: pointer;
      backdrop-filter: blur(4px);
      transition: background 0.2s ease, transform 0.1s ease;
    }
    .exit-btn:active {
      transform: scale(0.95);
      background: rgba(255, 255, 255, 0.3);
    }

    /* Full-screen Overlays (Start Page & Polaroid) */
    .screen-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: rgba(10, 8, 20, 0.75);
      backdrop-filter: blur(8px);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      z-index: 20;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.4s ease;
    }
    .screen-overlay.active {
      opacity: 1;
      pointer-events: auto;
    }

    /* Start Card */
    .start-card {
      background: rgba(255, 255, 255, 0.95);
      padding: 32px 24px;
      border-radius: 20px;
      text-align: center;
      max-width: 85%;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
      transform: scale(0.9);
      transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    }
    .screen-overlay.active .start-card {
      transform: scale(1);
    }
    .start-card h1 {
      color: #ff4081;
      font-size: 1.8rem;
      margin-bottom: 12px;
    }
    .start-card p {
      color: #4a4a4a;
      font-size: 0.98rem;
      line-height: 1.5;
      margin-bottom: 24px;
    }

    /* Polaroid Card Modal */
    .polaroid {
      background: #ffffff;
      padding: 14px 14px 22px 14px;
      border-radius: 6px;
      box-shadow: 0 15px 35px rgba(0,0,0,0.5);
      width: 280px;
      text-align: center;
      transform: rotate(-3deg) scale(0.7);
      transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    }
    .screen-overlay.active .polaroid {
      transform: rotate(2deg) scale(1);
    }
    .polaroid-img-container {
      width: 100%;
      height: 220px;
      background: #f0f0f0;
      border-radius: 3px;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: inset 0 0 10px rgba(0,0,0,0.15);
    }
    .polaroid-img-container img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .polaroid-caption {
      margin-top: 14px;
      font-family: 'Segoe UI', cursive, sans-serif;
      color: #333;
      font-size: 0.98rem;
      line-height: 1.4;
      font-weight: 600;
      padding: 0 6px;
    }

    .btn {
      background: linear-gradient(45deg, #ff4081, #ff80ab);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: 25px;
      font-size: 1rem;
      font-weight: bold;
      cursor: pointer;
      box-shadow: 0 4px 15px rgba(255, 64, 129, 0.4);
      transition: transform 0.1s ease;
    }
    .btn:active {
      transform: scale(0.96);
    }