/* ベーシックなリセット */
html{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 全体に「貂明朝」を適用 */
body {
  font-family: "ten-mincho", serif;
  font-weight: 400;
  font-style: normal;
  line-height: 1.6;
  scroll-behavior: smooth; /* スムーズスクロールを適用 */
  background: linear-gradient(135deg, #f0f4ff, #ffffff);
}

#hero-header {
  background-size: cover;
  background-position: center;
  height: 100; /* 全画面表示 */
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  font-size: 3em;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
  z-index: 1;
}

.upheader {
  background-image: url("./image/plum_blossoms.jpg");
  background-position: center;
  background-size: cover; /* 画像を全体にフィット */
  height: 500px; /* 高さを指定 */
  width:100%;
  display: flex; /* フレックスボックスを使用 */
  justify-content: center; /* 中央寄せ */
  align-items: center; /* 中央寄せ */
  color: #ddd;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5); /* 文字に影を付ける */
  font-size:65px; /*文字の大きさ調整*/
  padding:0 !important;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
  border:2px solid #747474;
  /*-ms-filter: sepia(60%);
  filter: sepia(60%);*/
  -ms-filter: saturate(200%);
  filter: saturate(200%);
  -ms-filter: contrast(120%);
  filter: contrast(120%);
  /*-ms-filter: brightness(110%);
  filter: brightness(110%);*/
}

/* カーソルを合わせたときに拡大 */
header nav a:hover {
  transform: scale(1.3); /* 拡大率 */
}

/* ヘッダー内のナビゲーションリンク */
header nav a {
  color: #fff;
  text-decoration: none;
  transition: transform 0.3s ease; /* 拡大アニメーションの設定 */
  display: inline-block; /* transformを適用するために追加 */
  padding: 10px;
}

/* ヘッダーのスタイル */
header {

  top: 0;
  width: 100%;
  color: #fdfdfd;
  text-align: center;
  z-index: 1000;
  /*background-image: url("梅の花.jpg");
  background-size: cover; /* 画像を全体にフィット */
  /*background-position: center; /* 中央に配置 */
}

/* ヘッダーのナビゲーションを上部に固定 */
header nav {
  position: fixed;
  top: 0;
  width: 100%;
  background-color:#333;
  z-index: 4;
}

/* フォントを貂明朝に指定（Webフォントとして読み込んでいる前提） */
  pre, code {
    font-family: 'ten-mincho', Courier, monospace; /* 等幅フォントで読みやすく */
    font-size: 1rem; /* フォントサイズを調整 */
    background-color: #f9f9f9; /* 明るいグレーの背景色 */
    color: #333; /* 濃い文字色で視認性を向上 */
    padding: 10px; /* 内側の余白を追加 */
    border: 1px solid #ddd; /* 薄い枠線を追加 */
    border-radius: 5px; /* 角を丸くする */
    display: block; /* ブロック要素として表示 */
    white-space: pre-wrap; /* 折り返しを有効にする */
    overflow-x: auto; /* 横スクロールを有効にする */
  }

  button {
    margin-top: 10px; /* ボタンの上に余白を追加 */
    padding: 5px 10px; /* ボタンの内側の余白を調整 */
    background-color: #f9f9f9; /* ボタンの背景色（青） */
    color: #333; /* ボタンの文字色（白） */
    border: 1px solid #ddd; /* 枠線を削除 */
    border-radius: 5px; /* 角を丸くする */
    cursor: pointer; /* カーソルをポインタに変更 */
    transition: background-color 0.3s ease; /* ホバー時のアニメーション */
    }

  
  button:hover {
    background-color: #007BFF; /* ホバー時の背景色を濃い青に変更 */
    color: #fff; /* ホバー時の文字色を白に変更 */
  }

  /* フッターのスタイル */
footer {
  text-align: center;
  padding: 10px;
  background: #333;
  color: #fff;
  margin-top: 20px;
  width : 100%;
}

/* トップへ戻るボタンのコンテナ */
.back-to-top-container {
  display: flex;
  justify-content: center;
  margin-bottom: 20px; /* フッターとの間隔を調整 */
}

/* トップへ戻るボタンのスタイル */
#back-to-top {
  background-color: #163717; /* ボタンの背景色 */
  color: white; /* 文字色 */
  padding: 10px 15px; /* ボタンの余白 */
  border-radius: 50px; /* 丸みを追加 */
  text-decoration: none; /* 下線を削除 */
  font-size: 14px; /* フォントサイズ */
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2); /* 影を追加 */
  transition: opacity 0.3s ease, transform 0.3s ease; /* アニメーション */
}

#back-to-top:hover {
  background-color: #28612b; /* ホバー時の背景色変更 */
  transform: translateY(-6px); /* 少し浮き上がる */
}

  .demo-flex {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
    gap: 20px; /* 要素間のスペースを調整 */
  }

  /* Three.js 3D花園 メインタイトル */
.title {
    background: linear-gradient(135deg, #ff6b9d 0%, #ffc0cb 100%);
    color: white;
    text-align: center;
    padding: 3rem 2rem;
    margin: 3rem auto 1rem auto;
    border-radius: 20px;
    box-shadow: 0 15px 40px rgba(255, 107, 157, 0.3);
    position: relative;
    overflow: hidden;
    max-width: 1200px;
    font-size: 2.4rem;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.title::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    z-index: 0;
    animation: rotate 25s linear infinite;
}

.contents-flex {
  display: flex;
    flex-direction: column;
    align-items: center;
    margin: 40px 0;
 
}

.canvas-container {
            display: flex;
            flex-direction: column;
            gap: 20px;
            align-items: center;
        }

         /* body { 
            margin: 0; 
            padding: 20px;
            background: linear-gradient(135deg, #1e3c72, #2a5298); 
            font-family: Arial, sans-serif;
        } */
        
        .demo-section {
            background: rgba(255, 255, 255, 0.1);
            border-radius: 15px;
            padding: 20px;
            margin-bottom: 20px;
        }
        
        canvas { 
            display: block; 
            border-radius: 10px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
        }
        
        .info {
            color: white;
            background: rgba(0,0,0,0.5);
            padding: 15px;
            border-radius: 10px;
            font-size: 16px;
            text-align: center;
            margin-bottom: 15px;
        }
        
        h1 {
            color: white;
            text-align: center;
            margin-bottom: 30px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
        }

.contents {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(255, 240, 245, 0.9));
    border-radius: 20px;
    padding: 40px;
    margin: 20px;
    max-width: 700px;
    width: 90%;
    box-shadow: 
        0 15px 35px rgba(0, 0, 0, 0.1),
        0 5px 15px rgba(255, 105, 180, 0.1);
    border: 2px solid rgba(255, 182, 193, 0.3);
    position: relative;
    overflow: hidden;
}

@keyframes floatBackground {
    0%, 100% { transform: rotate(0deg) scale(1); }
    50% { transform: rotate(5deg) scale(1.05); }
}

.contents h1 {
    color: #2c3e50;
    font-size: 2.5em;
    text-align: center;
    margin-bottom: 35px;
    font-weight: 700;
    position: relative;
    z-index: 1;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.contents h1::after {
    content: '✨';
    position: absolute;
    right: -60px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.2em;
    animation: sparkle 3s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(-50%) scale(1); }
    50% { transform: translateY(-60%) scale(1.1); }
}

@keyframes sparkle {
    0%, 100% { transform: translateY(-50%) rotate(0deg); opacity: 1; }
    25% { transform: translateY(-55%) rotate(10deg); opacity: 0.8; }
    75% { transform: translateY(-45%) rotate(-10deg); opacity: 0.8; }
}

/* タイトル下の装飾線 */
.contents h1::after {
    content: '';
    display: block;
    width: 120px;
    height: 4px;
    background: linear-gradient(90deg, #ff69b4, #ffc0cb, #ff69b4);
    margin: 20px auto;
    border-radius: 2px;
    animation: gradientShift 3s ease-in-out infinite;
}

@keyframes gradientShift {
    0%, 100% { background: linear-gradient(90deg, #ff69b4, #ffc0cb, #ff69b4); }
    50% { background: linear-gradient(90deg, #ffc0cb, #ff69b4, #ffc0cb); }
}

/* ==================== 目次リストのスタイル ==================== */
.contents ul {
    list-style: none;
    padding: 0;
    margin: 0;
    position: relative;
    z-index: 1;
}

.contents li {
    margin: 20px 0;
    padding: 18px 25px 18px 60px;
    position: relative;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border-left: 5px solid transparent;
    font-size: 1.1em;
    font-weight: 500;
    color: #2c3e50;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
}

/* 各項目の番号とアイコン */
.contents li::before {
    content: counter(li-counter);
    counter-increment: li-counter;
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    width: 30px;
    height: 30px;
    background: linear-gradient(135deg, #ff69b4, #ffc0cb);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 0.9em;
    box-shadow: 0 3px 10px rgba(255, 105, 180, 0.3);
    transition: all 0.3s ease;
}

.contents ul {
    counter-reset: li-counter;
}

/* リストアイテムのレイアウト調整 */
.contents li {
    margin: 20px 0;
    padding: 18px 25px;
    position: relative;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border-left: 5px solid transparent;
    font-size: 1.1em;
    font-weight: 500;
    color: #2c3e50;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    display: flex;
    align-items: center;
    justify-content: space-between; /* 要素を両端に配置 */
}

/* 左側のアイコンとテキストのコンテナ */
.contents li .left-content {
    display: flex;
    align-items: center;
    flex: 1;
}

/* 左側のメニューアイコン */
.menu-icon {
    width: 24px;
    height: 24px;
    object-fit: contain;
    margin-right: 12px;
    vertical-align: middle;
    transition: all 0.3s ease;
    filter: brightness(1) saturate(1);
}

/* 右側の桜アイコン */
.right-icon {
    width: 28px;
    height: 28px;
    object-fit: contain;
    margin-left: 12px;
    transition: all 0.3s ease;
    opacity: 0.6;
    filter: brightness(1) saturate(1);
}

/* ホバー時の効果 */
.contents li:hover .menu-icon {
    transform: scale(1.2) rotate(5deg);
    filter: brightness(1.2) saturate(1.3);
}

.contents li:hover .right-icon {
    opacity: 1;
    transform: scale(1.2) rotate(15deg);
    filter: brightness(1.2) saturate(1.3) drop-shadow(0 3px 8px rgba(255, 105, 180, 0.4));
}

/* 番号の位置調整 */
.contents li::before {
    content: counter(li-counter);
    counter-increment: li-counter;
    position: absolute;
    left: -15px;
    top: 50%;
    transform: translateY(-50%);
    width: 30px;
    height: 30px;
    background: linear-gradient(135deg, #ff69b4, #ffc0cb);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 0.9em;
    box-shadow: 0 3px 10px rgba(255, 105, 180, 0.3);
    transition: all 0.3s ease;
    z-index: 2;
}

/* ホバー効果 */
.contents li:hover {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.9), rgba(255, 240, 245, 0.8));
    transform: translateX(10px) scale(1.02);
    box-shadow: 
        0 8px 25px rgba(255, 105, 180, 0.2),
        0 3px 10px rgba(0, 0, 0, 0.1);
    border-left-color: #ff69b4;
    color: #2c3e50;
}

.contents li:hover::before {
    background: linear-gradient(135deg, #ff1493, #ff69b4);
    transform: translateY(-50%) scale(1.1) rotate(360deg);
    box-shadow: 0 5px 15px rgba(255, 105, 180, 0.4);
}

/* クリック効果 */
.contents li:active {
    transform: translateX(8px) scale(0.98);
}

.contents li:nth-child(1) { animation: slideInLeft 0.6s ease-out 0.1s both; }
.contents li:nth-child(2) { animation: slideInLeft 0.6s ease-out 0.2s both; }
.contents li:nth-child(3) { animation: slideInLeft 0.6s ease-out 0.3s both; }
.contents li:nth-child(4) { animation: slideInLeft 0.6s ease-out 0.4s both; }
.contents li:nth-child(5) { animation: slideInLeft 0.6s ease-out 0.5s both; }

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Introduction セクションの基本スタイル */
.Introduction {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 15px;
    padding: 2.5rem;
    margin: 1.5rem 0;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
}

/* 背景装飾 */
.Introduction::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 182, 193, 0.1) 0%, transparent 70%);
    z-index: -1;
    animation: float 6s ease-in-out infinite;
}

/* 見出しのスタイル */
.Introduction h2 {
    color: #2c3e50;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 1.2rem;
    padding-left: 1rem;
    border-left: 4px solid #ff69b4;
    position: relative;
}

/* 特別な見出し装飾 */
.Introduction h2:first-of-type {
    border-left-color: #4ecdc4;
}

.Introduction h2:first-of-type::after {
    background: linear-gradient(90deg, #4ecdc4, #a8edea);
}

.Introduction h2:nth-of-type(2) {
    border-left-color: #45b7d1;
}

.Introduction h2:nth-of-type(2)::after {
    background: linear-gradient(90deg, #45b7d1, #96c9dc);
}

.Introduction h2:nth-of-type(3) {
    border-left-color: #f39c12;
}

.Introduction h2:nth-of-type(3)::after {
    background: linear-gradient(90deg, #f39c12, #f7dc6f);
}

/* 段落のスタイル */
.Introduction p {
    line-height: 1.8;
    color: #34495e;
    font-size: 1rem;
    margin-bottom: 1.5rem;
    padding: 0 0.5rem;
    text-align: justify;
    position: relative;
}

.Introduction p::first-line {
    font-weight: 500;
    color: #2c3e50;
}

.Introduction button:hover {
    background: linear-gradient(135deg, #ee5a6f 0%, #ff6b6b 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.4);
}

.Introduction button:active {
    transform: translateY(0);
    box-shadow: 0 2px 5px rgba(255, 107, 107, 0.3);
}

/* アニメーション */
@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-10px) rotate(2deg); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.Introduction {
    animation: fadeInUp 0.8s ease-out;
}

/* スクロール効果 */
.Introduction {
    opacity: 0;
    transform: translateY(50px);
    animation: fadeInUp 1s ease-out forwards;
}

/* Canvas Container の基本スタイル */
.canvas-container {
    background: linear-gradient(135deg, #f8fffe 0%, #f0f8ff 100%);
    padding: 3rem 2rem;
    margin: 2rem auto;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
    max-width: 1200px;
}

/* 背景装飾 */
.canvas-container::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 182, 193, 0.05) 0%, transparent 70%);
    z-index: -1;
    animation: rotate 20s linear infinite;
}

/* タイトルのスタイル */
.canvas-container h1 {
    text-align: center;
    color: #2c3e50;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    position: relative;
    background: linear-gradient(45deg, #ff6b9d, #c44569);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.canvas-container h1::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: -10px;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background: linear-gradient(90deg, #ff6b9d, #c44569);
    border-radius: 2px;
}

/* Demo Flex レイアウト */
.demo-flex {
    display: flex;
    gap: 2rem;
    margin-bottom: 3rem;
    align-items: flex-start;
    flex-wrap: wrap;
}

/* Demo Section スタイル */
.demo-section {
    background: rgba(255, 255, 255, 0.9);
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    flex: 1;
    min-width: 350px;
}

/* Canvas要素のスタイル */
.demo-section canvas {
    border: 3px solid transparent;
    border-radius: 12px;
    background: linear-gradient(45deg, #f8f9fa, #e9ecef);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    display: block;
    margin: 0 auto;
    position: relative;
}

.demo-section canvas:hover {
    border-color: rgba(255, 107, 157, 0.5);
    box-shadow: 0 8px 30px rgba(255, 107, 157, 0.2);
    transform: scale(1.02);
}

/* Demo Explain セクション */
.demo-explain {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
    border-left: 5px solid #ff6b9d;
    flex: 1;
    min-width: 300px;
    position: relative;
}

.demo-explain p {
    line-height: 1.8;
    color: #34495e;
    font-size: 1rem;
    margin-bottom: 1.5rem;
    text-align: justify;
}

.demo-explain p::first-line {
    font-weight: 600;
    color: #2c3e50;
}

.demo-explain summary::-webkit-details-marker {
    display: none;
}

.demo-explain details[open] summary::after {
    transform: rotate(180deg);
}

.demo-explain button:hover {
    background: linear-gradient(135deg, #e55a87 0%, #b53f5e 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 157, 0.4);
}

.demo-explain button:active {
    transform: translateY(0);
    box-shadow: 0 2px 5px rgba(255, 107, 157, 0.3);
}

/* アニメーション */
@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-10px) rotate(5deg); }
}

@keyframes shine {
    0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
    100% { transform: translateX(100%) translateY(100%) rotate(45deg); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.demo-flex {
    animation: fadeInUp 0.8s ease-out;
}

/* スクロール効果 */
.canvas-container {
    opacity: 0;
    transform: translateY(50px);
    animation: fadeInUp 1s ease-out forwards;
}

/* グリッドレイアウトの代替案 */
@supports (display: grid) {
    .demo-flex {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
        align-items: start;
    }
    
    @media (max-width: 768px) {
        .demo-flex {
            grid-template-columns: 1fr;
        }
    }
}

/* 製作時間セクション */
.time-section {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 15px;
    padding: 2.5rem;
    margin: 1.5rem 0;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
}

.time-section::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 182, 193, 0.1) 0%, transparent 70%);
    z-index: -1;
    animation: float 6s ease-in-out infinite;
}

.time-section h1 {
    color: #2c3e50;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 1.2rem;
    padding-left: 1rem;
    border-left: 4px solid #ff69b4;
    position: relative;
    text-align: left; /* 中央揃えを左揃えに変更 */
    text-shadow: none;
}

.time-section p {
    line-height: 1.8;
    color: #34495e;
    font-size: 2.0rem; 
    font-weight: 500;
    margin-bottom: 1.5rem;
    padding: 0 0.5rem;
    text-align: center; /* 時間表示は中央揃えを維持 */
    position: relative;
}

.time-section p::first-line {
    font-weight: 600;
    color: #2c3e50;
}

.time-section {
    animation: fadeInUp 0.8s ease-out;
}

/* スクロール効果（Introductionと同じ） */
.time-section {
    opacity: 0;
    transform: translateY(50px);
    animation: fadeInUp 1s ease-out forwards;
}

/* 中央配置の統一 */
.time-section {
    margin-left: auto;
    margin-right: auto;
    max-width: 800px; /* 幅制限を追加 */
}

/* 参考資料セクション  */
.reference-content {
    background:  #f3f9f1 ;
    padding: 3rem 2rem;
    margin: 2rem auto 3rem auto;
    border-radius: 20px;
    position: relative;
    overflow: hidden;
    max-width: 1000px;
}

.reference-content h1 {
    color: #2c3e50;
    font-size: 2.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 2.0rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    position: relative;
    text-shadow: none;
    z-index: 1;
}

.reference-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
    position: relative;
    z-index: 1;
}

.reference-content li {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.reference-content li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #8d6e63, #a1887f, #bcaaa4);
    border-radius: 15px 15px 0 0;
}

.reference-content h3 {
    color: #2c3e50;
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 0.8rem;
    padding-left: 1rem;
    border-left: 4px solid #8d6e63;
    position: relative;
}

.reference-content h3::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -5px;
    width: 50px;
    height: 2px;
    background: linear-gradient(90deg, #8d6e63, #a1887f);
    border-radius: 1px;
}

.reference-content p {
    color: #2c3e50;
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 1.2rem;
    padding-left: 1rem;
}

.reference-content .reference-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: #6d4c41;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 0.8rem 1.5rem;
    background: rgba(141, 110, 99, 0.1);
    border-radius: 25px;
    border: 2px solid rgba(141, 110, 99, 0.3);
    transition: all 0.3s ease;
    margin-left: 1rem;
    word-break: break-all;
}

.reference-content .reference-link:hover {
    background: rgba(141, 110, 99, 0.2);
    border-color: rgba(121, 85, 72, 0.5);
    transform: translateX(5px);
    color: #4e342e;
    box-shadow: 0 4px 15px rgba(141, 110, 99, 0.3);
}

/* glow アニメーション修正 */
@keyframes glow {
    0% { 
        text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.4);
        transform: scale(1);
    }
    100% { 
        text-shadow: 3px 3px 15px rgba(255, 255, 255, 0.6), 0 0 20px rgba(255, 255, 255, 0.4);
        transform: scale(1.02);
    }
}

/* 各セクションが確実に中央に配置されるようにする */
.contents,
.Introduction,
.canvas-container,
.time-section,
.reference-content,
.title {
    margin-left: auto;
    margin-right: auto;
}