* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Hiragino Sans', 'Meiryo', sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    min-height: 100vh;
    color: #fff;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
}

.hidden {
    display: none !important;
}

/* メインメニュー画面 */
#menu-screen {
    text-align: center;
    width: 100%;
}

.menu-logo {
    width: 400px;
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.5);
    flex-shrink: 0;
}

.menu-buttons {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.expansion-info {
    font-size: 1rem;
    color: #bdc3c7;
    background: rgba(255, 255, 255, 0.1);
    padding: 10px 20px;
    border-radius: 10px;
}

#current-expansion {
    color: #3498db;
    font-weight: bold;
}

/* ユーザー登録画面 */
#register-screen {
    text-align: center;
}

.register-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 100%;
    max-width: 300px;
}

#username-input {
    padding: 15px 20px;
    font-size: 1.1rem;
    border: 2px solid #3498db;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
    text-align: center;
}

#username-input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.register-note {
    font-size: 0.85rem;
    color: #7f8c8d;
}

/* メニューのユーザー情報 */
.user-info {
    font-size: 1.2rem;
    color: #2ecc71;
    margin-bottom: 10px;
}

#user-display-name {
    font-weight: bold;
}

/* マイページ画面 */
#mypage-screen {
    width: 100%;
    max-width: 600px;
}

.mypage-content {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 20px;
}

.mypage-user-info {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 15px;
    margin-bottom: 15px;
}

.mypage-name {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    font-size: 1.5rem;
    color: #3498db;
    font-weight: bold;
    margin-bottom: 15px;
}

.mypage-stats {
    display: flex;
    justify-content: center;
    gap: 30px;
}

.stat-item {
    text-align: center;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: #7f8c8d;
    margin-bottom: 5px;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: bold;
    color: #f39c12;
}

.history-title {
    font-size: 1.1rem;
    color: #bdc3c7;
    margin-bottom: 15px;
    text-align: center;
}

.game-history {
    max-height: 300px;
    overflow-y: auto;
}

.history-item {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    padding: 15px;
    margin-bottom: 10px;
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.history-date {
    font-size: 0.85rem;
    color: #7f8c8d;
}

.history-score {
    font-size: 1.2rem;
    font-weight: bold;
}

.history-score.good {
    color: #2ecc71;
}

.history-score.medium {
    color: #f39c12;
}

.history-score.bad {
    color: #e74c3c;
}

.history-expansions {
    font-size: 0.8rem;
    color: #9b59b6;
    margin-bottom: 10px;
}

.history-results {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.history-card {
    width: 50px;
    height: 70px;
    border-radius: 4px;
    overflow: hidden;
    border: 2px solid;
    position: relative;
}

.history-card.correct {
    border-color: #2ecc71;
}

.history-card.wrong {
    border-color: #e74c3c;
}

.history-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.history-card .card-status {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.7);
    text-align: center;
    font-size: 0.7rem;
    padding: 2px;
}

.history-card.correct .card-status {
    color: #2ecc71;
}

.history-card.wrong .card-status {
    color: #e74c3c;
}

.no-history {
    text-align: center;
    color: #7f8c8d;
    padding: 30px;
}

/* ランキングモードボタン */
.btn-ranking {
    background: linear-gradient(45deg, #f39c12, #e67e22);
    color: #fff;
    box-shadow: 0 4px 15px rgba(243, 156, 18, 0.4);
}

.btn-ranking:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(243, 156, 18, 0.6);
}

.btn-casual-endless {
    background: linear-gradient(45deg, #8e44ad, #6c3483);
    color: #fff;
    box-shadow: 0 4px 15px rgba(142, 68, 173, 0.4);
}

.btn-casual-endless:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(142, 68, 173, 0.6);
}

/* ランキング画面 */
#ranking-screen {
    width: 100%;
    max-width: 600px;
}

.ranking-my-info {
    display: flex;
    justify-content: center;
    gap: 40px;
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 20px;
}

.my-rank-display,
.my-score-display {
    text-align: center;
}

.my-rank-label,
.my-score-label {
    display: block;
    font-size: 0.9rem;
    color: #7f8c8d;
    margin-bottom: 5px;
}

.my-rank-value {
    font-size: 2.5rem;
    font-weight: bold;
    color: #f39c12;
}

.my-score-value {
    font-size: 2.5rem;
    font-weight: bold;
    color: #2ecc71;
}

.ranking-actions {
    margin-bottom: 20px;
}

.ranking-table-container {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    overflow: hidden;
    margin-bottom: 20px;
}

.ranking-table-header {
    display: flex;
    padding: 10px 12px;
    background: rgba(52, 152, 219, 0.3);
    font-weight: bold;
    font-size: 0.85rem;
}

.ranking-table-header .col-rank {
    width: 44px;
    text-align: center;
}

.ranking-table-header .col-name {
    flex: 1;
}

.ranking-table-header .col-score {
    width: 80px;
    text-align: right;
}

.ranking-table {
    max-height: 350px;
    overflow-y: auto;
}

.ranking-row {
    display: flex;
    align-items: center;
    padding: 10px 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: background 0.2s;
}

.ranking-row:hover {
    background: rgba(255, 255, 255, 0.05);
}

.ranking-row.my-row {
    background: rgba(46, 204, 113, 0.2);
}

.ranking-row.top-3 {
    background: rgba(243, 156, 18, 0.1);
}

.ranking-row .col-rank {
    width: 44px;
    text-align: center;
    font-weight: bold;
}

.ranking-row.top-3 .col-rank {
    font-size: 1.3rem;
}

.ranking-row:nth-child(1) .col-rank { color: #f1c40f; }
.ranking-row:nth-child(2) .col-rank { color: #bdc3c7; }
.ranking-row:nth-child(3) .col-rank { color: #cd7f32; }

.ranking-row .col-name {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ranking-row .col-score {
    width: 80px;
    text-align: right;
    font-weight: bold;
    color: #2ecc71;
}

.ranking-loading,
.ranking-empty {
    text-align: center;
    padding: 40px;
    color: #7f8c8d;
}

.ranking-error {
    text-align: center;
    padding: 40px;
    color: #e74c3c;
}

/* ランキング結果表示 */
.ranking-result-info {
    background: rgba(243, 156, 18, 0.2);
    border: 2px solid #f39c12;
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: center;
}

.ranking-points-earned {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.ranking-points-earned .points {
    font-size: 2rem;
    font-weight: bold;
    color: #f39c12;
}

.ranking-total-points {
    font-size: 0.95rem;
    color: #bdc3c7;
}

.ranking-total-points .total {
    font-weight: bold;
    color: #2ecc71;
}

/* エキスパンション選択画面 */
#expansion-screen {
    width: 100%;
    max-width: 600px;
}

.screen-title {
    font-size: 2rem;
    color: #f39c12;
    margin-bottom: 10px;
}

.expansion-search {
    width: 100%;
    margin-bottom: 15px;
}

#expansion-search-input {
    width: 100%;
    padding: 12px 20px;
    font-size: 1rem;
    border: 2px solid #3498db;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
}

#expansion-search-input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.expansion-list {
    width: 100%;
    max-height: 350px;
    overflow-y: auto;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    padding: 10px;
    margin-bottom: 15px;
}

.expansion-item {
    display: flex;
    align-items: center;
    padding: 10px 15px;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s;
    margin-bottom: 5px;
}

.expansion-item:hover {
    background: rgba(255, 255, 255, 0.1);
}

.expansion-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin-right: 15px;
    cursor: pointer;
}

.expansion-item label {
    flex: 1;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.expansion-item .card-count {
    font-size: 0.9rem;
    color: #7f8c8d;
}

/* グループ化されたエキスパンションリスト */
.expansion-series {
    margin-bottom: 5px;
}

.series-header {
    display: flex;
    align-items: center;
    padding: 12px 15px;
    background: rgba(52, 152, 219, 0.2);
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s;
    margin-bottom: 2px;
}

.series-header:hover {
    background: rgba(52, 152, 219, 0.3);
}

.series-header .collapse-icon {
    width: 20px;
    font-size: 0.8rem;
    color: #3498db;
    transition: transform 0.2s;
    margin-right: 10px;
}

.series-header.collapsed .collapse-icon {
    transform: rotate(-90deg);
}

.series-header input[type="checkbox"] {
    width: 18px;
    height: 18px;
    margin-right: 12px;
    cursor: pointer;
    accent-color: #3498db;
}

.series-header .series-name {
    flex: 1;
    font-weight: bold;
    color: #3498db;
}

.series-header .series-count {
    font-size: 0.85rem;
    color: #7f8c8d;
}

.series-content {
    padding-left: 15px;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.series-content.collapsed {
    max-height: 0 !important;
    padding: 0;
}

.subseries-header {
    display: flex;
    align-items: center;
    padding: 10px 12px;
    background: rgba(155, 89, 182, 0.15);
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s;
    margin: 2px 0;
}

.subseries-header:hover {
    background: rgba(155, 89, 182, 0.25);
}

.subseries-header .collapse-icon {
    width: 18px;
    font-size: 0.75rem;
    color: #9b59b6;
    transition: transform 0.2s;
    margin-right: 8px;
}

.subseries-header.collapsed .collapse-icon {
    transform: rotate(-90deg);
}

.subseries-header input[type="checkbox"] {
    width: 16px;
    height: 16px;
    margin-right: 10px;
    cursor: pointer;
    accent-color: #9b59b6;
}

.subseries-header .subseries-name {
    flex: 1;
    font-weight: 600;
    color: #9b59b6;
    font-size: 0.95rem;
}

.subseries-header .subseries-count {
    font-size: 0.8rem;
    color: #7f8c8d;
}

.subseries-content {
    padding-left: 12px;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.subseries-content.collapsed {
    max-height: 0 !important;
    padding: 0;
}

/* グループ内のエキスパンション項目 */
.series-content .expansion-item,
.subseries-content .expansion-item {
    padding: 8px 12px;
    margin-bottom: 2px;
    font-size: 0.95rem;
}

.series-content .expansion-item input[type="checkbox"],
.subseries-content .expansion-item input[type="checkbox"] {
    width: 16px;
    height: 16px;
    margin-right: 10px;
}

/* エキスパンション名の詳細表示 */
.expansion-item .expansion-code {
    color: #f39c12;
    font-weight: bold;
    margin-right: 8px;
    font-size: 0.85rem;
}

.expansion-item .expansion-detail-name {
    color: #bdc3c7;
    font-size: 0.85rem;
}

/* チェックボックスのindeterminate状態 */
input[type="checkbox"]:indeterminate {
    opacity: 0.7;
}

.expansion-actions {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.btn-secondary {
    background: linear-gradient(45deg, #3498db, #2980b9);
    color: #fff;
    box-shadow: 0 4px 15px rgba(52, 152, 219, 0.4);
}

.btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.6);
}

.btn-external {
    background: linear-gradient(45deg, #27ae60, #219a52);
    color: #fff;
    box-shadow: 0 4px 15px rgba(39, 174, 96, 0.4);
    text-decoration: none;
    text-align: center;
}

.btn-external:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(39, 174, 96, 0.6);
}

.btn-small {
    padding: 10px 20px;
    font-size: 0.9rem;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.btn-small:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* タイトル画面 */
#title-screen {
    text-align: center;
}

.game-title {
    font-size: 3rem;
    background: linear-gradient(45deg, #f39c12, #e74c3c, #9b59b6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
    filter: drop-shadow(2px 2px 4px rgba(0,0,0,0.5));
    line-height: 1.3;
}

.subtitle {
    font-size: 1.5rem;
    color: #bdc3c7;
}

/* ボタン */
.btn {
    padding: 15px 40px;
    font-size: 1.2rem;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    -webkit-appearance: none;
    touch-action: manipulation;
}

.btn-primary {
    background: linear-gradient(45deg, #e74c3c, #c0392b);
    color: #fff;
    box-shadow: 0 4px 15px rgba(231, 76, 60, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(231, 76, 60, 0.6);
}

.btn-submit {
    background: linear-gradient(45deg, #27ae60, #2ecc71);
    color: #fff;
    padding: 12px 30px;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(46, 204, 113, 0.4);
}

/* ゲーム画面 */
#game-screen {
    width: 100%;
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: 15px 20px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    margin-bottom: 20px;
    gap: 15px;
}

.btn-quit {
    padding: 8px 12px;
    font-size: 1rem;
    background: rgba(231, 76, 60, 0.3);
    color: #e74c3c;
    border: 1px solid #e74c3c;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    flex-shrink: 0;
}

.btn-quit:hover {
    background: rgba(231, 76, 60, 0.5);
    transform: scale(1.05);
}

.progress, .timer, .score {
    font-size: 1.2rem;
    font-weight: bold;
}

.timer {
    color: #f39c12;
}

.timer-icon {
    margin-right: 5px;
}

.score {
    color: #2ecc71;
}

/* カード表示エリア */
.card-display-area {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 20px;
    margin: 20px 0;
}

.card-container {
    display: flex;
    justify-content: center;
}

.card-wrapper {
    position: relative;
    max-width: 300px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.card-wrapper img {
    width: 100%;
    height: auto;
    display: block;
}

/* ========== ハードモード ========== */
#hard-mode-canvas {
    position: absolute;
    inset: 0;
    z-index: 3;
    pointer-events: none;
    border-radius: 10px;
}

.btn-hard-mode-off {
    background: linear-gradient(45deg, #636e72, #4a5568);
    color: #fff;
    box-shadow: 0 4px 15px rgba(99, 110, 114, 0.4);
    padding: 15px 40px;
    font-size: 1.2rem;
    border-radius: 50px;
    font-weight: bold;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-hard-mode-off:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(99, 110, 114, 0.6);
}

.btn-hard-mode-on {
    background: linear-gradient(45deg, #6c5ce7, #a29bfe);
    color: #fff;
    box-shadow: 0 4px 15px rgba(108, 92, 231, 0.5);
    padding: 15px 40px;
    font-size: 1.2rem;
    border-radius: 50px;
    font-weight: bold;
    border: 2px solid #a29bfe;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-hard-mode-on:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(108, 92, 231, 0.7);
}

.hard-mode-description {
    font-size: 0.75rem;
    color: #aaa;
    margin: 4px 0 8px;
    text-align: center;
    line-height: 1.5;
}

.image-error-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    background: rgba(20, 20, 40, 0.85);
    border-radius: 10px;
    z-index: 5;
}

.image-error-overlay.hidden {
    display: none;
}

.image-error-text {
    color: #ccc;
    font-size: 0.85rem;
    text-align: center;
    margin: 0;
}

/* カード統計表示 */
.card-stats {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 15px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    min-width: 120px;
    text-align: center;
}

.accuracy-display {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.accuracy-label {
    font-size: 0.9rem;
    color: #bdc3c7;
}

.accuracy-value {
    font-size: 2rem;
    font-weight: bold;
    color: #2ecc71;
}

.accuracy-value.low {
    color: #e74c3c;
}

.accuracy-value.medium {
    color: #f39c12;
}

.accuracy-value.high {
    color: #2ecc71;
}

.attempt-count {
    font-size: 0.85rem;
    color: #7f8c8d;
}

/* 入力エリア */
.input-container {
    display: flex;
    gap: 15px;
    width: 100%;
    max-width: 500px;
    margin: 20px auto;
}

.autocomplete-wrapper {
    flex: 1;
    position: relative;
}

#answer-input {
    width: 100%;
    padding: 15px 20px;
    font-size: 1.1rem;
    border: 2px solid #3498db;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
    transition: border-color 0.3s;
}

#answer-input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

#answer-input:focus {
    border-color: #2ecc71;
}

/* 入力予測 */
.suggestions {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #2c3e50;
    border: 1px solid #34495e;
    border-radius: 0 0 10px 10px;
    max-height: 200px;
    overflow-y: auto;
    z-index: 100;
    list-style: none;
}

.suggestions li {
    padding: 12px 20px;
    cursor: pointer;
    transition: background 0.2s;
    border-bottom: 1px solid #34495e;
}

.suggestions li:last-child {
    border-bottom: none;
}

.suggestions li:hover,
.suggestions li.selected {
    background: #3498db;
}

/* フィードバック（カード画像中央にオーバーレイ） */
.feedback {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 15px 30px;
    border-radius: 10px;
    font-size: 1.2rem;
    font-weight: bold;
    text-align: center;
    animation: fadeIn 0.3s ease;
    z-index: 10;
    width: 90%;
    max-width: 280px;
    pointer-events: none;
}

.feedback.correct {
    background: rgba(46, 204, 113, 0.85);
    border: 2px solid #2ecc71;
    color: #fff;
}

.feedback.incorrect {
    background: rgba(231, 76, 60, 0.85);
    border: 2px solid #e74c3c;
    color: #fff;
}

.feedback.timeout {
    background: rgba(243, 156, 18, 0.85);
    border: 2px solid #f39c12;
    color: #fff;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translate(-50%, -50%) scale(0.9); }
    to { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

/* 結果画面 */
#result-screen {
    text-align: center;
}

.result-title {
    font-size: 2.5rem;
    color: #f39c12;
    margin-bottom: 20px;
}

.result-content {
    background: rgba(255, 255, 255, 0.1);
    padding: 40px;
    border-radius: 20px;
    margin-bottom: 30px;
}

.final-score {
    margin-bottom: 20px;
}

#final-score-value {
    font-size: 5rem;
    font-weight: bold;
    background: linear-gradient(45deg, #f39c12, #e74c3c);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.score-label {
    font-size: 1.5rem;
    color: #bdc3c7;
}

.rank {
    font-size: 2rem;
    margin: 20px 0;
    padding: 15px 30px;
    border-radius: 10px;
}

.rank.master {
    background: linear-gradient(45deg, #f1c40f, #f39c12);
    color: #000;
}

.rank.expert {
    background: linear-gradient(45deg, #9b59b6, #8e44ad);
}

.rank.advanced {
    background: linear-gradient(45deg, #3498db, #2980b9);
}

.rank.intermediate {
    background: linear-gradient(45deg, #2ecc71, #27ae60);
}

.rank.beginner {
    background: linear-gradient(45deg, #95a5a6, #7f8c8d);
}

.result-details {
    margin-top: 30px;
    text-align: left;
    max-height: 400px;
    overflow-y: auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
    padding: 10px;
}

.result-item {
    display: flex;
    flex-direction: column;
    padding: 12px;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid transparent;
    transition: border-color 0.2s;
}

.result-item.correct-answer {
    border-color: rgba(46, 204, 113, 0.5);
}

.result-item.wrong-answer {
    border-color: rgba(231, 76, 60, 0.5);
}

.result-card-image {
    width: 100%;
    max-width: 150px;
    margin: 0 auto 10px;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

.result-card-image img {
    width: 100%;
    height: auto;
    display: block;
}

.result-card-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 5px;
}

.result-card-info .status {
    font-size: 1.8rem;
    font-weight: bold;
}

.result-card-info .card-name {
    font-size: 0.95rem;
    line-height: 1.4;
}

.result-item.correct-answer .status {
    color: #2ecc71;
}

.result-item.wrong-answer .status {
    color: #e74c3c;
}

.result-card-info .user-answer {
    font-size: 0.85rem;
    color: #e74c3c;
    margin-top: 5px;
}

.result-card-info .timeout-label {
    font-size: 0.85rem;
    color: #f39c12;
}

/* スクロールバー */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: #3498db;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #2980b9;
}

/* レスポンシブ */
@media (max-width: 600px) {
    .menu-logo {
        width: 280px;
    }

    .game-title {
        font-size: 2rem;
    }

    .game-header {
        flex-direction: column;
        gap: 10px;
    }

    .card-display-area {
        flex-direction: column;
        align-items: center;
    }

    .card-stats {
        flex-direction: row;
        justify-content: center;
        min-width: auto;
        width: 100%;
        max-width: 300px;
    }

    .accuracy-display {
        flex-direction: row;
        align-items: center;
        gap: 10px;
    }

    .accuracy-value {
        font-size: 1.5rem;
    }

    .input-container {
        flex-direction: column;
    }

    .card-wrapper {
        max-width: 250px;
    }

    .result-content {
        padding: 20px;
    }

    #final-score-value {
        font-size: 3.5rem;
    }

    .result-details {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
        max-height: 350px;
    }

    .result-card-image {
        max-width: 100px;
    }

    .result-card-info .card-name {
        font-size: 0.8rem;
    }

    .result-card-info .status {
        font-size: 1.5rem;
    }

    /* 認証画面レスポンシブ */
    .auth-buttons {
        max-width: 100%;
    }

    .email-auth-actions {
        flex-direction: column;
    }

    /* カテゴリ選択レスポンシブ */
    .category-buttons {
        grid-template-columns: 1fr;
    }

    .btn-category {
        padding: 15px 12px;
    }

    /* エンドレス結果レスポンシブ */
    .endless-streak-value {
        font-size: 3.5rem;
    }

    /* フレンド管理レスポンシブ */
    .mypage-friend-id {
        flex-direction: column;
        gap: 5px;
    }

    .friend-search {
        flex-direction: column;
    }

    /* ゲームヘッダーのストリーク表示 */
    .streak-display {
        font-size: 0.9rem;
    }

    /* 一時停止バナーレスポンシブ */
    .paused-actions {
        flex-direction: column;
    }
}

/* ========== 認証画面 ========== */
#auth-screen {
    text-align: center;
}

.auth-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 100%;
    max-width: 320px;
}

.btn-google {
    background: #fff;
    color: #333;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.btn-google:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.btn-twitter {
    background: #000;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.btn-twitter:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

.auth-icon {
    font-size: 1.3rem;
    font-weight: bold;
    width: 24px;
    text-align: center;
}

.auth-divider {
    display: flex;
    align-items: center;
    gap: 15px;
    margin: 5px 0;
    color: #7f8c8d;
    font-size: 0.9rem;
}

.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: rgba(255, 255, 255, 0.2);
}

.email-auth-form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.email-auth-form input {
    padding: 12px 18px;
    font-size: 1rem;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
    transition: border-color 0.3s;
}

.email-auth-form input::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

.email-auth-form input:focus {
    border-color: #3498db;
}

.email-auth-actions {
    display: flex;
    gap: 10px;
}

.btn-email {
    flex: 1;
    padding: 12px 15px;
    font-size: 1rem;
    background: linear-gradient(45deg, #3498db, #2980b9);
    color: #fff;
    box-shadow: 0 2px 8px rgba(52, 152, 219, 0.3);
}

.btn-email:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.5);
}

.btn-email-secondary {
    flex: 1;
    padding: 12px 15px;
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.1);
    color: #bdc3c7;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-email-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.btn-anonymous {
    background: linear-gradient(45deg, #636e72, #2d3436);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.btn-anonymous:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

.anonymous-warning {
    font-size: 0.78rem;
    color: #e74c3c;
    line-height: 1.5;
    text-align: left;
    background: rgba(231, 76, 60, 0.1);
    border: 1px solid rgba(231, 76, 60, 0.2);
    border-radius: 8px;
    padding: 10px 12px;
}

.auth-error {
    color: #e74c3c;
    background: rgba(231, 76, 60, 0.15);
    border: 1px solid rgba(231, 76, 60, 0.3);
    padding: 10px 20px;
    border-radius: 10px;
    font-size: 0.9rem;
    max-width: 320px;
}

.auth-loading {
    color: #3498db;
    font-size: 1rem;
    padding: 10px;
}

/* ========== 名前設定画面 ========== */
#set-name-screen {
    text-align: center;
}

#set-name-input {
    padding: 15px 20px;
    font-size: 1.1rem;
    border: 2px solid #3498db;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
    text-align: center;
    width: 100%;
}

#set-name-input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

/* ========== カジュアルモード画面 ========== */
#casual-mode-screen {
    width: 100%;
    max-width: 500px;
    text-align: center;
}

#casual-mode-screen .expansion-info {
    margin-bottom: 10px;
}

#casual-mode-screen .menu-buttons {
    margin-bottom: 20px;
}

/* ========== ランキングカテゴリ選択画面 ========== */
#ranking-category-screen {
    width: 100%;
    max-width: 500px;
    text-align: center;
}

.category-description {
    font-size: 1rem;
    color: #bdc3c7;
    margin-bottom: 10px;
}

.category-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    width: 100%;
    margin-bottom: 20px;
}

.btn-category {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px 15px;
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.08);
    border: 2px solid rgba(255, 255, 255, 0.15);
    border-radius: 15px;
    color: #fff;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-category:hover {
    background: rgba(243, 156, 18, 0.2);
    border-color: #f39c12;
    transform: translateY(-3px);
}

.btn-category.btn-category-all {
    grid-column: 1 / -1;
}

.category-name {
    font-size: 1.2rem;
    font-weight: bold;
    margin-bottom: 5px;
}

.category-count {
    font-size: 0.8rem;
    color: #7f8c8d;
}

/* ========== ランキングカテゴリラベル ========== */
.ranking-category-label {
    font-size: 1.1rem;
    color: #f39c12;
    font-weight: bold;
    text-align: center;
    background: rgba(243, 156, 18, 0.15);
    padding: 8px 20px;
    border-radius: 20px;
    margin-bottom: 15px;
}

/* ========== 一時停止セッションバナー ========== */
.paused-session-banner {
    background: rgba(52, 152, 219, 0.2);
    border: 2px solid rgba(52, 152, 219, 0.4);
    border-radius: 15px;
    padding: 15px 20px;
    text-align: center;
    margin-bottom: 15px;
}

.paused-session-banner p {
    margin-bottom: 8px;
    color: #3498db;
    font-weight: bold;
}

.paused-streak {
    font-size: 1.2rem;
    color: #2ecc71;
}

.paused-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-top: 10px;
}

.paused-actions .btn {
    padding: 10px 20px;
    font-size: 0.95rem;
}

/* ========== ゲーム画面 ストリーク & 一時停止 ========== */
.streak-display {
    font-size: 1.1rem;
    font-weight: bold;
    color: #e74c3c;
    background: rgba(231, 76, 60, 0.15);
    padding: 4px 12px;
    border-radius: 15px;
}

.btn-pause {
    padding: 8px 12px;
    font-size: 1rem;
    background: rgba(52, 152, 219, 0.3);
    color: #3498db;
    border: 1px solid #3498db;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    flex-shrink: 0;
}

.btn-pause:hover {
    background: rgba(52, 152, 219, 0.5);
    transform: scale(1.05);
}

/* ========== エンドレス結果表示 ========== */
.endless-result {
    text-align: center;
    margin-bottom: 20px;
}

.endless-streak-display {
    margin-bottom: 15px;
}

.endless-streak-label {
    display: block;
    font-size: 1.2rem;
    color: #bdc3c7;
    margin-bottom: 5px;
}

.endless-streak-value {
    font-size: 5rem;
    font-weight: bold;
    background: linear-gradient(45deg, #e74c3c, #f39c12);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.new-best-badge {
    display: inline-block;
    background: linear-gradient(45deg, #f1c40f, #f39c12);
    color: #000;
    font-weight: bold;
    font-size: 1.2rem;
    padding: 8px 25px;
    border-radius: 25px;
    margin-bottom: 10px;
    animation: bestBadgePulse 1s ease-in-out infinite alternate;
}

@keyframes bestBadgePulse {
    from { transform: scale(1); box-shadow: 0 2px 10px rgba(243, 156, 18, 0.4); }
    to { transform: scale(1.05); box-shadow: 0 4px 20px rgba(243, 156, 18, 0.7); }
}

.endless-best-info {
    font-size: 0.95rem;
    color: #7f8c8d;
    margin-top: 10px;
}

/* ========== フレンド管理（マイページ内） ========== */
.mypage-friend-id {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.friend-id-label {
    font-size: 0.9rem;
    color: #7f8c8d;
}

.friend-id-value {
    font-size: 1.2rem;
    font-weight: bold;
    color: #f39c12;
    background: rgba(243, 156, 18, 0.15);
    padding: 4px 12px;
    border-radius: 8px;
    letter-spacing: 2px;
    font-family: 'Courier New', monospace;
}

.btn-tiny {
    padding: 5px 12px;
    font-size: 0.8rem;
    background: rgba(255, 255, 255, 0.1);
    color: #bdc3c7;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-tiny:hover {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.friend-section {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 15px;
    margin-top: 15px;
    margin-bottom: 15px;
}

.friend-section-title {
    font-size: 1.1rem;
    color: #bdc3c7;
    margin-bottom: 12px;
    text-align: center;
}

.friend-search {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
}

.friend-search input {
    flex: 1;
    padding: 10px 15px;
    font-size: 1rem;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-family: 'Courier New', monospace;
}

.friend-search input::placeholder {
    color: rgba(255, 255, 255, 0.4);
    text-transform: none;
    letter-spacing: normal;
    font-family: 'Hiragino Sans', 'Meiryo', sans-serif;
}

.friend-search input:focus {
    border-color: #3498db;
}

.friend-search-result {
    background: rgba(255, 255, 255, 0.08);
    border-radius: 10px;
    padding: 12px 15px;
    margin-bottom: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.friend-search-result .found-name {
    font-weight: bold;
    color: #3498db;
}

.friend-search-result .not-found {
    color: #e74c3c;
}

.friend-list {
    max-height: 200px;
    overflow-y: auto;
}

.friend-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    margin-bottom: 5px;
}

.friend-item .friend-name {
    font-weight: bold;
    color: #fff;
    flex: 1;
}

.friend-item .friend-id-badge {
    font-size: 0.8rem;
    color: #7f8c8d;
    margin-right: 10px;
    font-family: 'Courier New', monospace;
}

.no-friends {
    text-align: center;
    color: #7f8c8d;
    padding: 20px;
    font-size: 0.9rem;
}

.friend-limit-note {
    text-align: center;
    font-size: 0.8rem;
    color: #7f8c8d;
    margin-top: 5px;
}

.btn-remove-friend {
    background: rgba(231, 76, 60, 0.2);
    color: #e74c3c;
    border: 1px solid rgba(231, 76, 60, 0.3);
}

.btn-remove-friend:hover {
    background: rgba(231, 76, 60, 0.4);
}

.search-result-card {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.search-result-name {
    font-weight: bold;
    color: #3498db;
    font-size: 1.1rem;
}

.search-result-id {
    font-size: 0.85rem;
    color: #7f8c8d;
    font-family: 'Courier New', monospace;
}

.already-friend {
    font-size: 0.85rem;
    color: #2ecc71;
}

.btn-add-friend {
    background: rgba(46, 204, 113, 0.2);
    color: #2ecc71;
    border: 1px solid rgba(46, 204, 113, 0.3);
}

.btn-add-friend:hover {
    background: rgba(46, 204, 113, 0.4);
}

.search-result-error {
    color: #e74c3c;
    font-size: 0.9rem;
}

.search-result-loading {
    color: #3498db;
    font-size: 0.9rem;
}

/* ========== フレンドランキング ========== */
.friend-rankings-container {
    margin-bottom: 20px;
}

.friend-rankings-title {
    font-size: 1.1rem;
    color: #bdc3c7;
    margin-bottom: 10px;
    text-align: center;
}

.friend-rankings-table {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    overflow: hidden;
}

.friend-ranking-row {
    display: flex;
    align-items: center;
    padding: 10px 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.friend-ranking-row:last-child {
    border-bottom: none;
}

.friend-ranking-row .friend-ranking-name {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: #3498db;
    font-weight: bold;
}

.friend-ranking-row .friend-ranking-streak {
    width: 80px;
    text-align: right;
    font-weight: bold;
    color: #2ecc71;
}

/* ========== マイページ下部アクション ========== */
.mypage-bottom-actions {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 100%;
    max-width: 300px;
}

.btn-logout {
    padding: 12px 30px;
    font-size: 1rem;
    background: rgba(231, 76, 60, 0.2);
    color: #e74c3c;
    border: 1px solid rgba(231, 76, 60, 0.4);
}

.btn-logout:hover {
    background: rgba(231, 76, 60, 0.4);
}

/* カード画像の保護（右クリック・ドラッグ・選択防止） */
#card-image {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-user-drag: none;
    pointer-events: none;
}

.card-wrapper {
    position: relative;
    pointer-events: auto;
}

/* 画像の上に透明なオーバーレイを追加 */
.card-wrapper::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 5;
}

/* ========== 遊び方画面 ========== */
#howto-screen {
    width: 100%;
    max-width: 600px;
    text-align: center;
}

.howto-content {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 25px;
    text-align: left;
}

.howto-section {
    margin-bottom: 20px;
}

.howto-section:last-child {
    margin-bottom: 0;
}

.howto-heading {
    font-size: 1.2rem;
    color: #f39c12;
    margin-bottom: 8px;
    padding-bottom: 5px;
    border-bottom: 1px solid rgba(243, 156, 18, 0.3);
}

.howto-section p {
    font-size: 0.95rem;
    color: #bdc3c7;
    margin-bottom: 8px;
    line-height: 1.5;
}

.howto-section ul {
    list-style: none;
    padding: 0;
}

.howto-section ul li {
    font-size: 0.9rem;
    color: #ddd;
    padding: 5px 0 5px 20px;
    position: relative;
    line-height: 1.4;
}

.howto-section ul li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: #3498db;
}

/* ========== フッター ========== */
.site-footer {
    text-align: center;
    padding: 20px;
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.footer-link {
    color: #7f8c8d;
    font-size: 0.85rem;
    text-decoration: none;
    transition: color 0.2s;
}

.footer-rights {
    color: #aaa;
    font-size: 0.72rem;
    margin-top: 8px;
}

.footer-link:hover {
    color: #3498db;
    text-decoration: underline;
}

/* ========== プライバシーポリシー ========== */
.privacy-notice {
    text-align: center;
    font-size: 0.78rem;
    color: #aaa;
    margin-top: 16px;
}

.privacy-link {
    color: #7f8c8d;
    font-size: inherit;
    text-decoration: underline;
    cursor: pointer;
}

.privacy-link:hover {
    color: #3498db;
}

/* ========== 広告コンテナ ========== */
.ad-container {
    width: 100%;
    max-width: 600px;
    min-height: 0;
    margin: 10px auto;
    text-align: center;
}

/* ========== 管理者ボタン ========== */
.btn-admin {
    background: linear-gradient(45deg, #8e44ad, #9b59b6);
    color: #fff;
    box-shadow: 0 4px 15px rgba(155, 89, 182, 0.4);
}

.btn-admin:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(155, 89, 182, 0.6);
}

/* ========== 管理者画面 ========== */
#admin-screen {
    width: 100%;
    max-width: 600px;
}

.admin-content {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 20px;
}

.admin-section {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 20px;
}

.admin-section-title {
    font-size: 1.1rem;
    color: #f39c12;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 1px solid rgba(243, 156, 18, 0.3);
}

.readings-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 300px;
    overflow-y: auto;
}

.reading-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    padding: 10px 15px;
    gap: 10px;
}

.reading-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex: 1;
    min-width: 0;
}

.reading-card-name {
    font-weight: bold;
    color: #fff;
    font-size: 0.95rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.reading-text {
    color: #3498db;
    font-size: 0.9rem;
}

.reading-actions {
    display: flex;
    gap: 8px;
    flex-shrink: 0;
}

.btn-approve {
    background: rgba(46, 204, 113, 0.2);
    color: #2ecc71;
    border: 1px solid rgba(46, 204, 113, 0.3);
}

.btn-approve:hover {
    background: rgba(46, 204, 113, 0.4);
}

.btn-reject,
.btn-delete-reading {
    background: rgba(231, 76, 60, 0.2);
    color: #e74c3c;
    border: 1px solid rgba(231, 76, 60, 0.3);
}

.btn-reject:hover,
.btn-delete-reading:hover {
    background: rgba(231, 76, 60, 0.4);
}

.no-readings {
    text-align: center;
    color: #7f8c8d;
    padding: 20px;
    font-size: 0.9rem;
}

/* ========== 読み方登録モーダル ========== */
.reading-modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
}

.reading-modal.hidden {
    display: none;
}

.reading-modal-inner {
    background: #1a1a2e;
    border: 2px solid #3498db;
    border-radius: 15px;
    padding: 30px;
    width: 90%;
    max-width: 380px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.reading-modal-label {
    font-size: 1.1rem;
    font-weight: bold;
    color: #3498db;
    text-align: center;
    margin: 0;
}

.reading-modal-card-name {
    font-size: 1.15rem;
    font-weight: bold;
    color: #f39c12;
    text-align: center;
    margin: 0;
}

#reading-input {
    width: 100%;
    padding: 12px 18px;
    font-size: 1rem;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    outline: none;
    transition: border-color 0.3s;
}

#reading-input::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

#reading-input:focus {
    border-color: #3498db;
}

.reading-modal-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.reading-modal-feedback {
    text-align: center;
    font-size: 0.9rem;
    margin: 0;
    line-height: 1.4;
}

/* ========== リザルト画面の読み方登録ヒント ========== */
.reading-register-btn {
    cursor: pointer;
    position: relative;
}

.reading-register-hint {
    position: absolute;
    inset: 0;
    background: rgba(52, 152, 219, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: bold;
    color: #fff;
    border-radius: 8px;
    opacity: 0;
    transition: opacity 0.2s;
    pointer-events: none;
}

.reading-register-btn:hover .reading-register-hint {
    opacity: 1;
}

.reading-register-info {
    text-align: center;
    font-size: 0.78rem;
    color: #888;
    margin: 4px 0 8px;
}