body {
    background-image: url('260118_mokume.png');
    background-size: cover;
    background-position: center;
    box-sizing: border-box;
    margin: 0;
  }

  /* カレンダーページ専用のスタイル */
  .calendar-body {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding-top: 70px;
    height: 100vh;
    overscroll-behavior: none; /* ブラウザのプルリフレッシュ（リロード）を防止 */
    touch-action: none; /* ブラウザ標準のタッチ操作（スクロール等）を無効化 */
    overflow: hidden; /* 画面外へのスクロールを防止 */
    -webkit-user-select: none; /* Safari */
    -moz-user-select: none; /* Firefox */
    -ms-user-select: none; /* IE 10+ */
    user-select: none; /* Standard syntax */
  }

  /* カレンダー全体のコンテナ（位置決め用） */
  .calendar-container {
    position: relative;
    width: 90%;
    max-width: 360px;
    aspect-ratio: 2 / 3;
  }

  /* 共通の紙の質感 */
  .paper-part {
    background-color: #fdfbf7;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.12'/%3E%3C/svg%3E");
  }

  /* 上部の固定部分（スタブ） */
  .paper-stub {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 10%;
    z-index: 10;
    pointer-events: none; /* クリックを透過させる */
  }

  /* ミシン目 */
  .paper-stub::before {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    border-bottom: 3px dotted rgba(62, 58, 57, 0.5);
  }

  /* 黒い綴じ部分 */
  .paper-stub::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 50%;
    background-color: #3e3a39;
    border-radius: 2px 2px 0 0;
    z-index: 20; /* レイヤーより上に表示 */
  }

  /* 下部の可動部分（シート） */
  .paper-sheet {
    position: absolute;
    top: 10%;
    left: 0;
    width: 100%;
    height: 90%;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.12'/%3E%3C/svg%3E");
    border-radius: 0 0 2px 2px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    padding: 1rem 0.5rem 2rem 0.5rem;
    box-sizing: border-box;
    font-family: "Shippori Mincho", "Yu Mincho", serif;
    color: #3e3a39;
    transform-origin: top center;
    cursor: grab;
  }

  .header-info {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-top: auto;
  }
  
  .title-text {
    font-size: 1.6rem;
    letter-spacing: 0.1em;
  }

  .today-text {
    font-size: 1.1rem;
    opacity: 0.8;
  }

  .countdown-display {
    text-align: center;
  }

  .days-left {
    font-size: 8rem;
    font-weight: bold;
    line-height: 1;
  }

  .label {
    font-size: 1.2rem;
  }

  .unit {
    font-size: 1.5rem;
    margin-left: 0.5rem;
  }

  .hamburger-menu {
    position: absolute;
    top: -60px;
    right: 0;
    width: 50px;
    height: 50px;
    background-color: #fdfbf7;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    z-index: 10;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
  }

  .hamburger-menu span {
    display: block;
    width: 24px;
    height: 3px;
    background-color: #3e3a39;
    border-radius: 2px;
  }

  .undo-btn {
    position: absolute;
    bottom: -60px;
    left: 0;
    width: 50px;
    height: 50px;
    background-color: #fdfbf7;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    z-index: 10;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
  }

  .undo-btn::after {
    content: "";
    display: block;
    width: 12px;
    height: 12px;
    border-left: 3px solid #3e3a39;
    border-bottom: 3px solid #3e3a39;
    transform: rotate(45deg);
    margin-left: 4px;
  }

  /* 設定画面のスタイル */
  .settings-panel {
    display: none; /* 初期状態は非表示 */
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80%;
    max-width: 300px;
    background-color: #fdfbf7;
    padding: 2rem;
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
    border-radius: 4px;
    z-index: 100;
    font-family: "Shippori Mincho", serif;
    flex-direction: column;
    height: 80vh;
    overflow-y: auto;
    gap: 1.5rem;
  }

  .settings-panel.active {
    display: flex;
  }

  .settings-panel label {
    display: flex;
    flex-direction: column;
    font-weight: bold;
    color: #3e3a39;
  }

  .settings-panel input {
    margin-top: 0.5rem;
    padding: 0.5rem;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 2px;
    font-family: inherit;
    background-color: rgba(255,255,255,0.8);
    -webkit-user-select: text;
    user-select: text;
  }

  .close-btn {
    align-self: center;
    padding: 0.5rem 2rem;
    background-color: #3e3a39;
    color: #fdfbf7;
    border: none;
    border-radius: 2px;
    cursor: pointer;
    font-family: inherit;
  }

  .congrats-message {
    position: absolute;
    top: 55%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    text-align: center;
    font-family: "Shippori Mincho", serif;
    font-size: 2rem;
    font-weight: bold;
    color: #fdfbf7;
    text-shadow: 0 2px 10px rgba(0,0,0,0.8);
    z-index: 1;
    pointer-events: none;
  }

  .ad-placeholder {
    width: 100%;
    max-width: 320px;
    height: 50px;
    background-color: rgba(62, 58, 57, 0.05);
    border: 1px dashed rgba(62, 58, 57, 0.3);
    display: flex;
    justify-content: center;
    align-items: center;
    color: rgba(62, 58, 57, 0.6);
    font-size: 0.75rem;
    margin-top: auto;
  }