/* 5歳児向けのかわいい、丸みのあるフォントとデザイン */
    * {
      box-sizing: border-box;
      user-select: none;
      -webkit-user-select: none;
    }
    
    body {
      margin: 0;
      padding: 0;
      background-color: #b3e5fc; /* やさしいパステルブルー */
      font-family: "Hiragino Maru Gothic ProN", "Yu Gothic UI", "Meiryo", "MS Pgothic", sans-serif;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100dvh;
      overflow: hidden;
      touch-action: none;
    }

    #game-container {
      position: relative;
      width: 100%;
      max-width: 480px;
      height: 100dvh;
      max-height: 800px;
      box-shadow: 0 12px 36px rgba(0, 0, 0, 0.15);
      border-radius: 24px;
      overflow: hidden;
      background: linear-gradient(to bottom, #80deea, #e0f7fa);
      border: 8px solid #ffffff;
    }

    canvas {
      display: block;
      width: 100%;
      height: 100%;
    }

    /* UIレイヤー */
    .ui-layer {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 12px;
    }
    
    .ui-top {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      width: 100%;
      gap: 6px;
    }

    .score-board {
      background: rgba(255, 255, 255, 0.85);
      padding: 8px 12px;
      border-radius: 16px;
      box-shadow: 0 4px 10px rgba(0,0,0,0.05);
      pointer-events: auto;
      border: 3px solid #4dd0e1;
      flex-shrink: 0;
    }

    .score-text {
      font-size: 16px;
      font-weight: bold;
      color: #00838f;
      margin: 2px 0;
    }

    .lives-board {
      display: flex;
      gap: 4px;
      background: rgba(255, 255, 255, 0.85);
      padding: 6px 10px;
      border-radius: 16px;
      border: 3px solid #ff8a80;
      flex-shrink: 0;
    }

    .heart-icon {
      font-size: 20px;
      color: #ff5252;
      animation: heartbeat 1.5s infinite alternate ease-in-out;
    }

    @keyframes heartbeat {
      from { transform: scale(1); }
      to { transform: scale(1.15); }
    }

    .audio-hud-btn {
      background: rgba(255, 255, 255, 0.9);
      border: 3px solid #b2dfdb;
      border-radius: 50%;
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      pointer-events: auto;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      transition: transform 0.1s;
      font-size: 20px;
      outline: none;
      touch-action: manipulation;
    }
    
    .audio-hud-btn:active {
      transform: scale(0.9);
    }

    /* 画面下部アクションエリア */
    .ui-bottom {
      display: flex;
      justify-content: center;
      align-items: center;
      width: 100%;
      margin-bottom: 10px;
    }

    .drop-btn {
      background: linear-gradient(135deg, #ff7043, #f4511e);
      color: white;
      border: 4px solid #ffffff;
      border-radius: 50px;
      padding: 16px 48px;
      font-size: 26px;
      font-weight: bold;
      cursor: pointer;
      pointer-events: auto;
      box-shadow: 0 8px 0 #bf360c, 0 12px 20px rgba(0,0,0,0.2);
      transition: transform 0.05s, box-shadow 0.05s;
      text-shadow: 2px 2px 0px rgba(0, 0, 0, 0.2);
      letter-spacing: 2px;
    }

    .drop-btn:active {
      transform: translateY(6px);
      box-shadow: 0 2px 0 #bf360c, 0 4px 10px rgba(0,0,0,0.2);
    }

    /* メニュー画面オーバーレイ */
    .screen-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(to bottom, #80deea, #e0f7fa);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 30px;
      text-align: center;
      z-index: 10;
      transition: opacity 0.3s ease;
    }

    .screen-overlay.hidden {
      opacity: 0;
      pointer-events: none;
      display: none !important;
    }

    .hidden {
      display: none !important;
    }

    .game-title {
      font-size: 40px;
      font-weight: 900;
      color: #006064;
      margin-bottom: 10px;
      text-shadow: 3px 3px 0px #ffffff;
      line-height: 1.3;
    }

    .game-subtitle {
      font-size: 16px;
      color: #00838f;
      margin-bottom: 30px;
      background: #ffffff;
      padding: 6px 16px;
      border-radius: 20px;
      font-weight: bold;
    }

    .start-btn, .restart-btn {
      background: linear-gradient(135deg, #66bb6a, #43a047);
      color: white;
      border: 4px solid #ffffff;
      border-radius: 50px;
      padding: 16px 40px;
      font-size: 24px;
      font-weight: bold;
      cursor: pointer;
      box-shadow: 0 8px 0 #1b5e20, 0 12px 20px rgba(0,0,0,0.2);
      transition: transform 0.05s, box-shadow 0.05s;
      text-shadow: 2px 2px 0px rgba(0, 0, 0, 0.2);
    }

    .start-btn:active, .restart-btn:active {
      transform: translateY(6px);
      box-shadow: 0 2px 0 #1b5e20, 0 4px 10px rgba(0,0,0,0.2);
    }

    .result-container {
      background: white;
      border-radius: 24px;
      padding: 24px;
      border: 4px dashed #4dd0e1;
      margin-bottom: 30px;
      width: 100%;
      max-width: 320px;
      box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    }

    .result-title {
      font-size: 28px;
      color: #e53935;
      font-weight: bold;
      margin-bottom: 15px;
    }

    .result-score {
      font-size: 22px;
      color: #37474f;
      margin: 10px 0;
      font-weight: bold;
    }

    .highscore-badge {
      display: inline-block;
      background: #fff59d;
      color: #f57f17;
      padding: 4px 12px;
      border-radius: 12px;
      font-size: 14px;
      font-weight: bold;
      margin-top: 5px;
      border: 2px solid #fbc02d;
      animation: bounce 0.6s infinite alternate ease-in-out;
    }

    @keyframes bounce {
      from { transform: translateY(0); }
      to { transform: translateY(-6px); }
    }

    /* ガイドテキスト */
    .guide-text {
      position: absolute;
      bottom: 110px;
      left: 0;
      width: 100%;
      text-align: center;
      font-size: 18px;
      font-weight: bold;
      color: #00838f;
      text-shadow: 2px 2px 0px #ffffff;
      pointer-events: none;
      animation: pulse 1s infinite alternate ease-in-out;
    }

    @keyframes pulse {
      from { opacity: 0.6; }
      to { opacity: 1; }
    }

    /* かわいい装飾用の雪だるま */
    .title-illustration {
      width: 120px;
      height: 120px;
      margin-bottom: 20px;
      position: relative;
    }