/**
 * ============================================================================
 * 單篇文章無限滾動 - 完整 CSS 檔案 (v2.0)
 * ============================================================================
 *
 * @version 2.0.0
 * @description 整合所有優化效果的最終版本，適用於外部檔案載入。
 * - 更流暢的載入動畫與過渡效果。
 * - 引入骨架屏 (Skeleton Screen) 以提升感知效能。
 * - 保留並優化了響應式、Dark Mode、列印等現代化樣式。
 * - 結構化與註解更清晰，易於維護。
 */

/* ========================================================================= */
/* 0. 動畫定義 (Keyframes)
/* ========================================================================= */

/* 新載入內容的淡入+上移動畫 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 載入器旋轉動畫 */
@keyframes rotate {
    100% {
        transform: rotate(360deg);
    }
}

/* 載入器路徑動畫 */
@keyframes dash {
    0% {
        stroke-dasharray: 1, 150;
        stroke-dashoffset: 0;
    }
    50% {
        stroke-dasharray: 90, 150;
        stroke-dashoffset: -35;
    }
    100% {
        stroke-dasharray: 90, 150;
        stroke-dashoffset: -124;
    }
}

/* 骨架屏閃爍動畫 */
@keyframes shimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}


/* ========================================================================= */
/* 1. 新文章容器與分隔線
/* ========================================================================= */

.infinite-scroll-post {
    opacity: 0; /* 初始透明，等待動畫觸發 */
    animation: fadeInUp 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}

/* 確保文章之間有適當的視覺間隔，同時避免與分隔線的 margin 疊加 */
.infinite-scroll-post + .infinite-scroll-post {
    padding-top: 40px; /* 用 padding 代替 border-top，避免影響 box-sizing */
}

.infinite-scroll-divider {
    /* 預設不顯示，只在 JS 插入的新文章中顯示 */
    display: none;
    margin: 80px 0 60px;
    text-align: center;
    position: relative;
    opacity: 0; /* 初始透明 */
    animation: fadeInUp 0.7s 0.2s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards; /* 延遲出現 */
}

/* 為第一篇之後的所有文章啟用分隔線 */
.infinite-scroll-post + .infinite-scroll-post .infinite-scroll-divider {
    display: block;
}

.infinite-scroll-divider::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(to right, transparent, #e0e0e0 20%, #e0e0e0 80%, transparent);
}

.infinite-scroll-divider .divider-text {
    position: relative;
    display: inline-block;
    padding: 8px 25px;
    background: #fff;
    color: #a0a0a0;
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    border: 1px solid #e0e0e0;
    border-radius: 20px;
    z-index: 1; /* 確保文字在線上層 */
}


/* ========================================================================= */
/* 2. 載入觸發器、骨架屏與動畫
/* ========================================================================= */

.infinite-scroll-trigger {
    padding: 60px 20px;
    text-align: center;
    min-height: 200px;
    transition: opacity 0.4s ease;
    opacity: 0; /* 初始完全透明 */
}

/* 當 JS 設置為 loading 狀態時，才讓它淡入 */
.infinite-scroll-trigger[data-loading="true"] {
    opacity: 1;
}

/* 【新增】手動模式:當有按鈕時也要顯示 */
.infinite-scroll-trigger:has(#infinite-scroll-load-more-button) {
    opacity: 1;
}

/* 傳統載入器 (作為骨架屏的備用) */
.infinite-scroll-loader {
    display: none; /* 預設隱藏，優先使用骨架屏 */
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.infinite-scroll-loader .spinner {
    width: 45px;
    height: 45px;
    animation: rotate 1.8s linear infinite;
}

.infinite-scroll-loader .spinner .path {
    stroke: #4a5568;
    stroke-linecap: round;
    animation: dash 1.5s ease-in-out infinite;
}

.loading-text {
    margin: 0;
    color: #718096;
    font-size: 14px;
}

/* 手動載入按鈕 */
#infinite-scroll-load-more-button,
.load-more-button { /* 兼容舊 class name */
    background: #4a5568;
    color: #fff;
    border: none;
    padding: 12px 30px;
    font-size: 15px;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.3s, transform 0.2s;
}

#infinite-scroll-load-more-button:hover,
.load-more-button:hover {
    background: #2d3748;
    transform: translateY(-2px);
}


/* ========================================================================= */
/* 3. 骨架屏 (Skeleton Screen)
/* ========================================================================= */

.infinite-scroll-skeleton {
    display: none; /* 預設隱藏，由 JS 控制顯示 */
    padding: 40px 0;
}

.skeleton-wrapper {
    max-width: 100%;
    margin: auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
}

.skeleton-item {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: shimmer 1.8s infinite;
    border-radius: 4px;
}

.skeleton-title { height: 32px; width: 70%; margin-bottom: 20px; }
.skeleton-meta { height: 16px; width: 40%; margin-bottom: 30px; }
.skeleton-content { display: flex; flex-direction: column; gap: 12px; }
.skeleton-line { height: 16px; }
.skeleton-line:nth-child(1) { width: 100%; }
.skeleton-line:nth-child(2) { width: 95%; }
.skeleton-line:nth-child(3) { width: 98%; }


/* ========================================================================= */
/* 4. 結束訊息
/* ========================================================================= */

.infinite-scroll-end {
    padding: 70px 20px;
    text-align: center;
    background-color: #f7fafc;
    border-top: 1px solid #e2e8f0;
    margin: 60px 0;
    border-radius: 12px;
    position: relative; /* 為關閉按鈕定位 */
}

/* 關閉按鈕 */
.infinite-scroll-end-close {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 32px;
    height: 32px;
    background: rgba(0, 0, 0, 0.05);
    border: none;
    border-radius: 50%;
    font-size: 24px;
    line-height: 1;
    color: #718096;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

.infinite-scroll-end-close:hover {
    background: rgba(0, 0, 0, 0.1);
    color: #2d3748;
    transform: rotate(90deg);
}

.infinite-scroll-end-close:active {
    transform: rotate(90deg) scale(0.95);
}

.infinite-scroll-end p {
    font-size: 1.1em;
    color: #4a5568;
    margin: 0 0 25px 0;
    font-weight: 500;
}

.infinite-scroll-end .back-home {
    display: inline-block;
    padding: 12px 32px;
    background-color: #4a5568;
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.infinite-scroll-end .back-home:hover {
    background-color: #2d3748;
    transform: translateY(-3px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}

/* 結束區塊按鈕容器 */
.infinite-scroll-end-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    align-items: center;
}

/* 繼續載入最新文章按鈕 */
.infinite-scroll-end .load-latest-button {
    display: inline-block;
    padding: 12px 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.infinite-scroll-end .load-latest-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}


/* ========================================================================= */
/* 5. 哨兵元素 (不可見)
/* ========================================================================= */

.scroll-sentinel-top,
.scroll-sentinel-bottom {
    height: 1px;
    visibility: hidden;
    pointer-events: none;
}


/* ========================================================================= */
/* 6. 響應式設計
/* ========================================================================= */

@media (max-width: 768px) {
    .infinite-scroll-divider {
        margin: 60px 0 40px;
    }

    .infinite-scroll-trigger {
        padding: 40px 15px;
        min-height: 150px;
    }
    
    .infinite-scroll-end {
        margin: 40px 0; /* 在手機上可以移除左右負邊距，讓其填滿 */
        border-radius: 0;
        padding: 60px 20px;
    }
    
    .infinite-scroll-end p {
        font-size: 1rem;
    }
}


/* ========================================================================= */
/* 7. 無障礙與使用者偏好
/* ========================================================================= */

/* 焦點可見性 */
.infinite-scroll-end .back-home:focus-visible,
#infinite-scroll-load-more-button:focus-visible {
    outline: 3px solid #4a5568;
    outline-offset: 3px;
}

/* 減少動畫偏好 */
@media (prefers-reduced-motion: reduce) {
    .infinite-scroll-post,
    .infinite-scroll-divider,
    .infinite-scroll-loader .spinner,
    .infinite-scroll-end .back-home,
    #infinite-scroll-load-more-button,
    .skeleton-item {
        animation: none !important;
        transition: none !important;
    }
}


/* ========================================================================= */
/* 8. 列印樣式
/* ========================================================================= */

@media print {
    .infinite-scroll-trigger,
    .infinite-scroll-end,
    .infinite-scroll-divider {
        display: none !important;
    }
    
    .infinite-scroll-post {
        page-break-inside: avoid;
        break-inside: avoid;
        opacity: 1 !important; /* 確保在列印時可見 */
        transform: none !important;
    }
}


/* ========================================================================= */
/* 9. Dark Mode 支援 (可選)
/* ========================================================================= */

@media (prefers-color-scheme: dark) {
    /* 也可以使用 body.dark-mode 或 html.dark-mode 選擇器 */
    .infinite-scroll-divider::before {
        background: linear-gradient(to right, transparent, #3a3a3a 20%, #3a3a3a 80%, transparent);
    }
    
    .infinite-scroll-divider .divider-text {
        /*background: #1a1a1a;*/
        color: #999;
        border-color: #3a3a3a;
    }
    
    .loading-text {
        color: #999;
    }
    
    .infinite-scroll-loader .spinner .path {
        stroke: #999;
    }

    #infinite-scroll-load-more-button,
    .load-more-button {
        background: #555;
    }
    #infinite-scroll-load-more-button:hover,
    .load-more-button:hover {
        background: #777;
    }
    
    .infinite-scroll-end {
        background: #1a1a1a;
        border-top-color: #3a3a3a;
    }
    
    .infinite-scroll-end p {
        color: #999;
    }
    
    .infinite-scroll-end .back-home {
        background: #555;
    }
    .infinite-scroll-end .back-home:hover {
        background: #777;
    }

    .skeleton-item {
        background: linear-gradient(90deg, #2d2d2d 25%, #3a3a3a 50%, #2d2d2d 75%);
    }
}

/*
 * =======================================================
 *  無限滾動 - 廣告顯示與佈局最終修正
 * =======================================================
 */

/* 
 * 1. 確保新載入的廣告預設為隱藏，防止提前閃現。
 *    (由 JavaScript 負責在適當時機將其 display 改為 block)
 */
.infinite-scroll-post .ad-container-top {
    display: none;
}

/* 
 * 2. 例外規則：確保頁面首次載入時，第一篇文章的廣告是正常可見的。
 */
main#postshow-a > .infinite-scroll-post:first-of-type .ad-container-top {
    display: block;
}

/* 
 * 3. 【本次新增】為所有文章頂部的廣告容器增加上邊距，解決與分隔線緊貼的問題。
 *    這個樣式會對所有 .ad-container-top 生效，無論它是顯示還是隱藏。
 */
.infinite-scroll-post .ad-container-top {
    margin-top: 25px; /* 可根據需求調整數值 */
}

/*
 * 無限滾動 - 分隔線樣式修正
 * -------------------------------------
 * 確保 AJAX 載入的文章頂部分隔線永遠可見且有適當的間距。
 */
.infinite-scroll-post .infinite-scroll-divider {
    display: block ; /* 使用 !important 強制顯示 */
    text-align: center;
    padding: 20px 0;
    margin-top: 30px; /* 與上一篇文章的結尾產生間距 */
    margin-bottom: 30px; /* 與本篇文章的開頭產生間距 */
    color: #888;
}

/* 確保你的 CSS 有這些設定 */
#postshow-a .entry-title {
    word-wrap: break-word;
    overflow-wrap: break-word;
    word-break: break-word;
    hyphens: auto;
}

#postshow-a article {
    max-width: 100%;
    overflow: hidden;
}

#postshow-a .entry-header {
    max-width: 100%;
    overflow: hidden;
}

/* ========================================================================= */
/* WordPress Block Layout Fallback for Infinite Scroll
/* WordPress 動態生成的 wp-container-* 樣式在 AJAX 載入時可能缺失
/* ========================================================================= */

/* Flex Layout 基礎樣式 */
.infinite-scroll-post .wp-block-group.is-layout-flex,
.infinite-scroll-post .wp-block-columns.is-layout-flex {
    display: flex;
    gap: var(--wp--style--block-gap, 1.5rem);
}

/* Flex Nowrap */
.infinite-scroll-post .wp-block-group.is-layout-flex.is-nowrap {
    flex-wrap: nowrap;
}

/* 垂直對齊 */
.infinite-scroll-post .wp-block-group.is-layout-flex.is-vertical {
    flex-direction: column;
}

/* 水平對齊 */
.infinite-scroll-post .wp-block-group.is-layout-flex.is-content-justification-center {
    justify-content: center;
}

.infinite-scroll-post .wp-block-group.is-layout-flex.is-content-justification-space-between {
    justify-content: space-between;
}

/* Flex 子項目自動縮放 */
.infinite-scroll-post .wp-block-group.is-layout-flex > * {
    margin: 0;
}

/* Grid Layout 基礎樣式 */
.infinite-scroll-post .wp-block-group.is-layout-grid {
    display: grid;
    gap: var(--wp--style--block-gap, 1.5rem);
}

/* 響應式：小螢幕時 Flex 轉為垂直排列 */
@media (max-width: 600px) {
    .infinite-scroll-post .wp-block-group.is-layout-flex:not(.is-nowrap) {
        flex-wrap: wrap;
    }
}

/* ========================================================================= */
/* 分隔線樣式變體 (5 種選擇)
/* ========================================================================= */

/* 樣式 1: 經典 (Classic) - 預設樣式，已在上方定義 */
/* .infinite-scroll-divider 使用原本樣式 */

/* 樣式 2: 淡化 (Fade) - 淡灰色漸層線 */
.divider-style-fade .infinite-scroll-divider::before {
    background: linear-gradient(to right, transparent, rgba(0,0,0,0.05) 30%, rgba(0,0,0,0.05) 70%, transparent);
    height: 2px;
}
.divider-style-fade .infinite-scroll-divider .divider-text {
    background: transparent;
    border: none;
    color: #ccc;
    font-size: 12px;
    letter-spacing: 2px;
}

/* 樣式 3: 極簡 (Minimal) - 只有細線，無文字 */
.divider-style-minimal .infinite-scroll-divider {
    margin: 60px 0 40px;
}
.divider-style-minimal .infinite-scroll-divider::before {
    background: #eee;
    height: 1px;
}
.divider-style-minimal .infinite-scroll-divider .divider-text {
    display: none;
}

/* 樣式 4: 現代 (Modern) - 圓角標籤風格 */
.divider-style-modern .infinite-scroll-divider {
    margin: 70px 0 50px;
}
.divider-style-modern .infinite-scroll-divider::before {
    display: none;
}
.divider-style-modern .infinite-scroll-divider .divider-text {
    padding: 12px 30px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 1px;
    border: none;
    border-radius: 25px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.divider-style-modern .infinite-scroll-divider .divider-text:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

/* 樣式 5: 隱藏 (Hidden) - 完全不顯示 */
.divider-style-hidden .infinite-scroll-divider {
    display: none !important;
}

/* Dark Mode 支援各樣式 */
@media (prefers-color-scheme: dark) {
    .divider-style-fade .infinite-scroll-divider::before {
        background: linear-gradient(to right, transparent, rgba(255,255,255,0.1) 30%, rgba(255,255,255,0.1) 70%, transparent);
    }
    .divider-style-fade .infinite-scroll-divider .divider-text {
        color: #666;
    }
    
    .divider-style-minimal .infinite-scroll-divider::before {
        background: #333;
    }
}

/* ========================================================================= */
/* 新增載入器樣式 (Spinner, Progress, Dots, Wave)
/* ========================================================================= */

/* 載入器容器基礎樣式 */
.infinite-scroll-loader-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 60px 20px;
    min-height: 120px;
}

/* ========================================================================= */
/* Spinner 載入器
/* ========================================================================= */

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loader-spinner {
    border-radius: 50%;
    border-style: solid;
    animation: spin 0.8s linear infinite;
}

/* Spinner 大小變體 */
.loader-spinner.size-small {
    width: 30px;
    height: 30px;
    border-width: 3px;
}

.loader-spinner.size-medium {
    width: 45px;
    height: 45px;
    border-width: 4px;
}

.loader-spinner.size-large {
    width: 60px;
    height: 60px;
    border-width: 5px;
}

/* ========================================================================= */
/* Progress Bar 載入器
/* ========================================================================= */

@keyframes progress-indeterminate {
    0% {
        left: -40%;
        width: 40%;
    }
    100% {
        left: 100%;
        width: 40%;
    }
}

.loader-progress {
    width: 100%;
    max-width: 300px;
    overflow: hidden;
    border-radius: 10px;
    background: rgba(0, 0, 0, 0.1);
}

.loader-progress-bar {
    height: 100%;
    position: relative;
    animation: progress-indeterminate 1.5s cubic-bezier(0.65, 0.815, 0.735, 0.395) infinite;
}

/* Progress Bar 大小變體 */
.loader-progress.size-small {
    height: 4px;
    max-width: 200px;
}

.loader-progress.size-medium {
    height: 6px;
    max-width: 300px;
}

.loader-progress.size-large {
    height: 8px;
    max-width: 400px;
}

/* ========================================================================= */
/* Dots 載入器
/* ========================================================================= */

@keyframes dot-pulse {
    0%, 80%, 100% {
        transform: scale(0.8);
        opacity: 0.5;
    }
    40% {
        transform: scale(1.2);
        opacity: 1;
    }
}

.loader-dots {
    display: flex;
    gap: 12px;
    align-items: center;
}

.loader-dots .dot {
    border-radius: 50%;
    animation: dot-pulse 1.4s ease-in-out infinite;
}

.loader-dots .dot:nth-child(1) {
    animation-delay: 0s;
}

.loader-dots .dot:nth-child(2) {
    animation-delay: 0.2s;
}

.loader-dots .dot:nth-child(3) {
    animation-delay: 0.4s;
}

/* Dots 大小變體 */
.loader-dots.size-small .dot {
    width: 8px;
    height: 8px;
}

.loader-dots.size-medium .dot {
    width: 12px;
    height: 12px;
}

.loader-dots.size-large .dot {
    width: 16px;
    height: 16px;
}

/* ========================================================================= */
/* Wave 載入器
/* ========================================================================= */

@keyframes wave {
    0%, 40%, 100% {
        transform: scaleY(0.4);
    }
    20% {
        transform: scaleY(1);
    }
}

.loader-wave {
    display: flex;
    gap: 6px;
    align-items: center;
}

.loader-wave .bar {
    width: 4px;
    border-radius: 2px;
    animation: wave 1.2s ease-in-out infinite;
}

.loader-wave .bar:nth-child(1) {
    animation-delay: 0s;
}

.loader-wave .bar:nth-child(2) {
    animation-delay: 0.1s;
}

.loader-wave .bar:nth-child(3) {
    animation-delay: 0.2s;
}

.loader-wave .bar:nth-child(4) {
    animation-delay: 0.3s;
}

.loader-wave .bar:nth-child(5) {
    animation-delay: 0.4s;
}

/* Wave 大小變體 */
.loader-wave.size-small .bar {
    height: 30px;
    width: 3px;
}

.loader-wave.size-medium .bar {
    height: 45px;
    width: 4px;
}

.loader-wave.size-large .bar {
    height: 60px;
    width: 5px;
}

/* ========================================================================= */
/* Custom HTML 載入器
/* ========================================================================= */

/* 自訂 HTML 載入器不需要預設樣式，所有樣式由用戶在自訂 HTML 中定義 */

/* ========================================================================= */
/* Dark Mode 支援
/* ========================================================================= */

@media (prefers-color-scheme: dark) {
    .loader-progress {
        background: rgba(255, 255, 255, 0.1);
    }
    
    .infinite-scroll-loader-container {
        color: #e2e8f0;
    }
}

/* ========================================================================= */
/* 響應式設計
/* ========================================================================= */

@media (max-width: 600px) {
    .infinite-scroll-loader-container {
        padding: 40px 15px;
        min-height: 100px;
    }
    
    .loader-progress.size-large {
        max-width: 300px;
    }
    
    .loader-spinner.size-large {
        width: 50px;
        height: 50px;
        border-width: 4px;
    }
    
    .loader-wave.size-large .bar {
        height: 50px;
    }
}