html,
body {
    height: 100%;
    margin: 0;
    overflow: hidden;
    /* 禁止頁面捲動 */
}

body {
    position: relative;
    padding-top: 20px;
    padding-bottom: 20px;
    font-family: "Times New Roman", Times, serif;
    transition: background-color 0.3s, color 0.3s;
}

h2,
.h2 {
    font-family: "Times New Roman", Times, serif;
    /* font-size: 1.5rem ; */
    font-weight: 500;
    color: var(--bs-dark);
    transition: color 0.3s;
}

p {
    /* text-indent: 0.5in; */
    font-size: large;
    transition: color 0.3s;
}

blockquote {
    /* font-style: italic; */
    font-size: large;
    margin: 1rem;
    padding: 0.5em;
    border-left: 3px solid #ccc;
    padding-left: 10px;
    transition: color 0.3s;
}

img {
    max-width: 100%;
    height: auto;
}


/* Custom sidebar scrollbar styles */

#sidebar::-webkit-scrollbar {
    width: 5px;
}

#sidebar::-webkit-scrollbar-track {
    background: #e1e1e1;
}

#sidebar::-webkit-scrollbar-thumb {
    background: #cccccc;
    border-radius: 1px;
}

#sidebar::-webkit-scrollbar-thumb:hover {
    background: #00000033;
}

.dark-mode {
    background-color: #333;
    color: #d5d9dd;
    transition: color 0.3s;
}

.dark-mode h2 {
    color: #f8f9fa;
}

.dark-mode .h2 {
    color: #f8f9fa;
}

.dark-mode .datetime {
    color: #ddd;
    transition: color 0.3s;
}

.back-to-top {
    position: fixed;
    z-index: 100;
    bottom: 20px;
    right: 20px;
    background-color: #00000066;
    color: #fff;
    display: none;
}

.back-to-top:hover {
    background-color: #00000099;
    color: #fff;
}

.icon-button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    margin-left: 10px;
}

.language-dropdown {
    display: inline-block;
}


/* .subtitle {
    font-size: large;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.authornames {
    width: 100%;
    text-align: center;
    font-size: 1rem;
}
.datetime {
    width: 100%;
    text-align: center;
    font-size: 0.95rem;
    margin: 1.5px 0 2% 0;
    color: #414141;
    transition: color 0.3s;
} */

.apacite {
    text-indent: -0.5in;
    padding-left: 0.5in;
}

.content-wrapper {
    font-size: large;
    max-width: 100%;
}

.sidebar {
    position: sticky;
    top: 20px;
    height: calc(100vh - 40px);
    overflow-y: auto;
    transition: background-color 0.3s;
}

.position-sticky {
    padding-left: 1%;
    list-style: none;
    margin-top: 60px;
    margin-bottom: 50px;
}

.nav-link {
    transition: all 0.3s;
}

.nav-link:hover {
    transform: translateX(5px);
}

.nav-link.active {
    /* color: #007bff; */
    font-weight: bold;
}

.nxt-pagelink {
    color: #00bfff;
    text-shadow: 1px 0px 2px #00000050;
}

.main-content {
    display: flex;
    flex-direction: column;
    padding-left: 15px;
    padding-right: 15px;
}

.header-content {
    order: 0;
    text-align: center;
}

.content-wrapper {
    max-width: 97.5%;
}


/* @media (min-width: 768px) {
    .position-sticky{
        margin-top: 60px;
        margin-bottom: 50px;
    }
} */

.offcanvas {
    background-color: #ffffff !important;
    font-family: 'Segoe UI', sans-serif;
    font-size: 1rem;
    color: #212529;
}


/* 調整選單內部文字的內距與對齊 */

.offcanvas-body .nav-link,
.offcanvas-body .dropdown-item {
    padding-left: 1rem;
    padding-right: 1rem;
    /* font-weight: 500; */
    color: #333;
}


/* hover 效果一致 */

.offcanvas-body .nav-link:hover,
.offcanvas-body .dropdown-item:hover {
    text-decoration: underline;
    background-color: #f8f9fa;
}

.offcanvas-start {
    max-width: 250px;
}


/* 基本樣式與互動 */

.sidebar-tree .nav-link {
    color: #000000;
    padding: .4rem .25rem;
    font-family: "Times New Roman", Times, serif;
}

.sidebar-tree .nav-link:hover {
    text-decoration: underline;
}

.btn-toggle {
    background: transparent;
    border: 0;
    padding: .4rem .25rem;
    font-weight: 600;
}

.btn-toggle:hover {
    background-color: rgba(0, 0, 0, .04);
    border-radius: .5rem;
}


/* 小箭頭旋轉動畫 */

.btn-toggle .chevron {
    transition: transform .2s ease;
}

.btn-toggle:not(.collapsed) .chevron {
    transform: rotate(90deg);
}


/* 次層連結字級/間距更緊湊 */

.sidebar-tree .small {
    font-size: .92rem;
}


/* 緊密行距 & 無首行縮排 */

.tight-text p,
.tight-text {
    line-height: 1.2;
    /* 調整行距更緊密，預設大約 1.5 */
    text-indent: 0;
    /* 首行不縮排 */
    margin-bottom: 0.5rem;
    /* 段落之間縮小間距 */
}


/* ===== Sidebar 階層字級設定 ===== */

:root {
    --nav-l1: 1.28rem;
    /* 最上層：Introduction / ICLS / UNESCO / Participants / Others */
    --nav-l2: 1.12rem;
    /* 群組層：Online Forum / More Documents */
    --nav-l3: 1.00rem;
    /* 檔案葉節點 */
}

.navbar-nav .nav-link {
    font-weight: 400;
    /* 移除粗體 */
    line-height: 1.35;
    /* 舒適行距 */
    white-space: normal;
    /* 自動換行 */
    word-break: break-word;
    /* 長字/URL 可斷行 */
    overflow-wrap: anywhere;
    /* 避免撐出水平卷軸 */
    padding-left: 0;
    /* 由階層類別決定內距 */
}

.navbar-nav .nav-l1 {
    font-size: var(--nav-l1);
    padding: .35rem 0;
}

.navbar-nav .nav-l2 {
    font-size: var(--nav-l2);
    padding: .3rem 0;
    padding-left: .25rem;
}

.navbar-nav .nav-l3 {
    font-size: var(--nav-l3);
    padding: .25rem 0;
    padding-left: .5rem;
}


/* 巢狀 UL 的左縮排更乾淨 */

.navbar-nav .list-unstyled {
    margin-left: .25rem;
}


/* 展開箭頭動畫（可留可不留） */

.chevron {
    font-size: .9em;
    transition: transform .2s ease;
}

a.nav-link[aria-expanded="true"] .chevron {
    transform: rotate(90deg);
}


/* 安全：側欄容器只垂直滾動、不出現水平捲軸 */

.sidebar-tree,
nav.sticky-top {
    overflow-x: hidden;
}


/* ===== Sidebar 項目間距（依階層）===== */

:root {
    --gap-l1: .7rem;
    /* 最上層項目之間的距離 */
    --gap-l2: .5rem;
    /* 群組內（第二層）項目之間的距離 */
    --gap-l3: .4rem;
    /* 第三層（檔案列表）項目之間的距離 */
}


/* 讓清單用 flex column + gap 管理間距 */

.navbar-nav,
.navbar-nav .list-unstyled {
    display: flex;
    flex-direction: column;
    margin: 0;
    /* 清掉 ul 預設 margin */
    padding-left: 0;
    /* 由你原本的 ps-3 控制左縮排即可 */
}


/* 各層 gap 設定 */

.navbar-nav {
    gap: var(--gap-l1);
}

.navbar-nav .list-unstyled {
    gap: var(--gap-l2);
}

.navbar-nav .list-unstyled .list-unstyled {
    gap: var(--gap-l3);
}


/* 群組展開後，群組標題與清單間留一點空隙 */

.collapse>.list-unstyled {
    margin-top: .35rem;
}


/* 保險：避免長字撐出水平捲軸 */

.navbar-nav .nav-link {
    white-space: normal;
    word-break: break-word;
    overflow-wrap: anywhere;
}

@media (min-width: 1200px) {
    .content-wrapper {
        max-width: 87.5%;
    }
    .position-sticky {
        margin-top: 60px;
        margin-bottom: 50px;
    }
}

@media (max-width: 768px) {
    .sidebar {
        position: static;
        height: auto;
    }
    .header-content {
        margin-bottom: 20px;
    }
    .position-sticky {
        margin-top: 10px;
        margin-bottom: 10px;
    }
}

.title-tight {
    line-height: 1.1;
    margin: 0;
}

.subtitle-tight {
    line-height: 1.25;
    margin: 0;
    opacity: .9;
}

.underline-mono {
    display: block;
    height: 8px;
    /* 再加粗一點 */
    width: min(700px, 80%);
    /* 更長，最大 480px 或容器 80% */
    margin: 1.5rem auto 0;
    border-radius: 999px;
    background: linear-gradient( 90deg, #000000, #222222, #888888, #dddddd, #888888, #222222, #000000);
    background-size: 300% 100%;
    /* 放大漸層寬度，動畫更柔順 */
    animation: ug-shift 8s ease-in-out infinite;
}

@keyframes ug-shift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

.intro-title {
    display: flex;
    flex-direction: column;
    /* 垂直堆疊 */
    justify-content: center;
    /* 垂直方向置中（如果父容器有高度） */
    align-items: center;
    /* 水平方向置中 */
    text-align: center;
    /* 文字置中 */
    transform: translateY(-20%);
    /* 負值代表往上移，數字可自行調整 */
}

.title-inline {
    display: flex;
    justify-content: center;
    /* 水平置中 */
    align-items: baseline;
    /* 主副標基線對齊 */
    flex-wrap: wrap;
    /* 窄螢幕時自動換行 */
    gap: 0.5rem;
    /* 主副標間距 */
}

.main-center {
    display: flex;
    justify-content: center;
    /* 水平置中 */
    /* align-items: center;       垂直置中 */
    min-height: 100vh;
    /* 滿版高度 */
    align-items: flex-start;
    padding-top: 13vh;
}


/* 主標題放大 */

.intro-title .title-tight {
    font-size: clamp(4rem, 5vw, 3rem);
    /* 原本 display-6 大約 1.5–2rem，這裡放大 */
}

.intro-title .qtitle-tight {
    font-size: clamp(1.8rem, 5vw, 1.8rem);
    /* 原本 display-6 大約 1.5–2rem，這裡放大 */
}


/* 副標題放大 */

.intro-title .subtitle-tight {
    font-size: clamp(2rem, 3vw, 1.5rem);
    /* 原本 fs-4 大約 1.25rem，這裡放大 */
}