/* ===== CSS 變數：怪異巫師專屬色盤 ===== */
:root {
    --bg-primary: #FAFAFC;        /* 側邊欄底色 */
    --bg-secondary: #FCFCFD;      /* 主內容底色 (與內文 iframe 相同) */
    --bg-tertiary: #F0EBF5;       /* 懸停或選取時的淺紫背景 */
    
    --text-primary: #2A2A30;      /* 深炭黑 */
    --text-secondary: #4A4A52;
    --text-muted: #888899;
    
    --border-color: #D8D8E5;
    
    --accent-color: #4A235A;      /* 虛空深紫 */
    --accent-hover: #3D2645;
    --accent-gold: #D4AC0D;       /* 黃銅色 */
    
    --sidebar-width: 320px;       /* 稍微加寬，讓目錄文字更舒展 */
    --header-height: 55px;
    
    --shadow-md: 0 4px 15px rgba(74, 35, 90, 0.08);
    --shadow-drawer: -5px 0 20px rgba(0,0,0,0.1);
    
    --transition-speed: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* ===== 基礎重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
    height: 100%;
    font-family: "Palatino Linotype", "Book Antiqua", "Microsoft YaHei", serif; 
    font-size: 15px;
    color: var(--text-primary);
    background: var(--bg-secondary);
    overflow: hidden; /* 防止整個視窗滾動，依賴內部容器滾動 */
    /* 靜默防禦：禁止選取文字與拖拽 (全域) */
    user-select: none;
    -webkit-user-drag: none;
}

/* ===== 優雅的滾動條 ===== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(74, 35, 90, 0.2); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: rgba(74, 35, 90, 0.5); }

/* ===== 佈局容器 ===== */
.app-container { display: flex; height: 100vh; position: relative; width: 100%; }

/* ===== 側邊欄遮罩 (手機版) ===== */
.sidebar-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(42, 42, 48, 0.5);
    backdrop-filter: blur(2px);
    z-index: 900;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-speed);
}
.sidebar-overlay.active { opacity: 1; visibility: visible; }

/* ===== 側邊欄 ===== */
.sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    height: 100vh;
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-speed), width var(--transition-speed), min-width var(--transition-speed);
    z-index: 1000;
}

/* 電腦版側邊欄收起狀態 */
.sidebar.collapsed {
    transform: translateX(calc(-1 * var(--sidebar-width)));
    width: 0; min-width: 0; border-right: none;
}

.sidebar-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 20px;
    height: var(--header-height);
    background: var(--accent-color); /* 深紫頂部 */
    color: #FFF;
    border-bottom: 3px solid var(--accent-gold); /* 黃銅飾線 */
}

.site-title { font-size: 1.2rem; font-weight: bold; letter-spacing: 1px; font-family: "Cinzel", serif;}

.sidebar-toggle, .menu-toggle, .bookmarks-open-toggle, .bookmarks-toggle {
    background: transparent; border: none; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    width: 36px; height: 36px; border-radius: 4px;
    transition: all 0.2s;
}

.sidebar-toggle { color: #FFF; }
.sidebar-toggle:hover { background: rgba(255,255,255,0.1); }

/* ===== 標籤區 (裝飾性) ===== */
.sidebar-tabs {
    display: flex; background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}
.sidebar-tab {
    flex: 1; padding: 12px 16px; background: transparent; border: none;
    color: var(--accent-color); font-weight: bold; font-size: 1rem;
    pointer-events: none; /* 既然只有一個標籤，就不需要點擊 */
}

/* ===== 目錄樹 (分層明確，容易點擊) ===== */
.tab-content { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.toc-container { flex: 1; overflow-y: auto; padding: 15px 10px 30px 10px; }

.toc-item { margin: 2px 0; }

/* 展開/收合箭頭區域 */
.toc-toggle-icon {
    width: 24px; height: 24px;
    display: flex; align-items: center; justify-content: center;
    cursor: pointer; color: var(--text-muted);
    transition: transform 0.2s; flex-shrink: 0;
}
.toc-toggle-icon:hover { color: var(--accent-color); }
.expanded > .toc-folder-row > .toc-toggle-icon { transform: rotate(90deg); color: var(--accent-gold); }

/* 資料夾/條目 整行容器 */
.toc-folder-row {
    display: flex; align-items: center;
    border-radius: 4px; transition: background 0.2s;
}
.toc-folder-row:hover { background: var(--bg-tertiary); }

/* 條目文字連結 */
.toc-link {
    flex: 1; padding: 8px 10px 8px 5px;
    color: var(--text-primary); text-decoration: none;
    font-size: 0.95rem; cursor: pointer;
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.toc-link:hover { color: var(--accent-color); font-weight: bold; }
.toc-link.active { 
    color: var(--accent-color); font-weight: bold; 
    background: rgba(212, 172, 13, 0.1); /* 淡淡的黃銅底色 */
    border-left: 3px solid var(--accent-gold);
}

.toc-children { display: none; padding-left: 18px; border-left: 1px dashed var(--border-color); margin-left: 11px;}
.expanded > .toc-children { display: block; }

/* 沒有子層的單純檔案 (隱藏箭頭，保留縮排) */
.toc-file-only > .toc-folder-row > .toc-toggle-icon { visibility: hidden; }

/* ===== 主內容區 ===== */
.main-content {
    flex: 1; display: flex; flex-direction: column;
    min-width: 0; background: var(--bg-secondary);
    position: relative;
}

.content-header {
    display: flex; align-items: center;
    height: var(--header-height); padding: 0 15px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.menu-toggle { color: var(--text-secondary); margin-right: 15px; }
.menu-toggle:hover { background: var(--bg-tertiary); color: var(--accent-color); }

.breadcrumb {
    flex: 1; font-size: 0.9rem; color: var(--text-muted);
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
    font-family: sans-serif;
}
.breadcrumb-item { color: var(--accent-color); font-weight: bold;}

.bookmarks-open-toggle { color: var(--accent-gold); }
.bookmarks-open-toggle:hover { background: var(--bg-tertiary); }

.content-body { flex: 1; display: none; }
.content-body.active { display: block; }

/* iframe 無縫融合：無邊框，背景透明讓它吃主體的顏色 */
#contentFrame { width: 100%; height: 100%; border: none; background: transparent; }

/* ===== 書籤面板 ===== */
.bookmarks-panel {
    position: absolute; right: 0; top: 0; bottom: 0;
    width: 300px; background: var(--bg-primary);
    border-left: 1px solid var(--border-color);
    box-shadow: var(--shadow-drawer);
    display: flex; flex-direction: column;
    transform: translateX(0); transition: transform var(--transition-speed);
    z-index: 1000;
}
.bookmarks-panel.collapsed { transform: translateX(110%); box-shadow: none; }

.bookmarks-header {
    display: flex; justify-content: space-between; align-items: center;
    height: var(--header-height); padding: 0 20px;
    background: var(--accent-color); color: white;
    border-bottom: 3px solid var(--accent-gold);
}
.bookmarks-toggle { color: white; }

.bookmarks-actions { display: flex; gap: 10px; padding: 15px; border-bottom: 1px solid var(--border-color); }
.bookmarks-actions button {
    flex: 1; padding: 8px 0; border: none; border-radius: 4px;
    cursor: pointer; font-weight: bold; transition: 0.2s;
}
#addPageBookmark { background: var(--accent-color); color: white; }
#addPageBookmark:hover { background: var(--accent-gold); color: #000; }
#clearBookmarks { background: transparent; border: 1px solid #CCC; color: var(--text-secondary); }
#clearBookmarks:hover { border-color: #E74C3C; color: #E74C3C; }

.bookmarks-list { flex: 1; overflow-y: auto; padding: 10px; }
.bookmark-item {
    display: flex; padding: 10px; margin-bottom: 8px;
    background: var(--bg-secondary); border: 1px solid var(--border-color); border-radius: 4px;
    cursor: pointer; transition: 0.2s;
}
.bookmark-item:hover { border-color: var(--accent-gold); transform: translateY(-1px); }
.bookmark-content { flex: 1; overflow: hidden; }
.bookmark-title { font-weight: bold; color: var(--accent-color); margin-bottom: 4px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bookmark-delete { background: transparent; border: none; color: #CCC; cursor: pointer; padding: 5px; }
.bookmark-delete:hover { color: #E74C3C; }

.welcome-screen { flex: 1; display: flex; align-items: center; justify-content: center; text-align: center; }
.welcome-screen.hidden { display: none; }

/* ===== 響應式：手機版與平板 ===== */
@media (max-width: 768px) {
    .sidebar { position: fixed; left: 0; top: 0; box-shadow: 5px 0 15px rgba(0,0,0,0.1); }
    .sidebar.collapsed { transform: translateX(-100%); }
    .desktop-only { display: none; } /* 手機版隱藏原生的箭頭收起按鈕，改用點擊遮罩 */
    .bookmarks-panel { width: 100%; max-width: 320px; }
}

/* 浮動書籤按鈕 */
.floating-bookmark-button {
    position: fixed; padding: 8px 15px; background: var(--accent-gold); color: #000;
    border: none; border-radius: 4px; font-weight: bold; cursor: pointer;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2); z-index: 10000;
}