* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: "Microsoft JhengHei", "微軟正黑體", -apple-system, BlinkMacSystemFont, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            background-attachment: fixed;
            min-height: 100vh;
            overflow-x: hidden;
        }

        /* v1.18.0: container 上方加 transparent zone，body 紫色透過 header 區域顯現；
           blur 過渡在 95-130px 範圍內（接近 4 stats 上緣）就轉成 solid 白；
           底部 footer 漸層維持 v1.16 的 6-stop ease 配方 */
        .container {
            max-width: 1920px;
            margin: 0 auto;
            background:
                linear-gradient(
                    180deg,
                    transparent 0px,
                    transparent 95px,
                    rgba(248, 249, 250, 0.5) 110px,
                    rgba(248, 249, 250, 0.85) 120px,
                    #f8f9fa 132px,
                    #f8f9fa calc(100% - 280px),
                    rgba(248, 249, 250, 0.92) calc(100% - 230px),
                    rgba(248, 249, 250, 0.72) calc(100% - 180px),
                    rgba(248, 249, 250, 0.42) calc(100% - 120px),
                    rgba(248, 249, 250, 0.15) calc(100% - 60px),
                    transparent calc(100% - 10px),
                    transparent 100%
                );
            min-height: 100vh;
            position: relative;
        }

        /* 星星網絡背景 — v1.12.0: opacity 0.7 → 0.84 (+20% visibility) */
        #stellar-bg {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: 0;
            pointer-events: none;
            opacity: 0.84;
        }

        .content-wrapper {
            position: relative;
            z-index: 1;
        }

        .footer {
            position: relative;
            z-index: 1;
        }

        /* v1.18.0: header bg 全透明（跟 footer 一樣），靠 container 的上方 transparent zone 讓 body 紫色顯出來；
           blur 過渡由 container gradient 處理，延伸到接近 4 stats 上緣才轉白 */
        .header {
            background: transparent;
            padding: 25px 30px 22px;
            text-align: center;
            position: relative;
            z-index: 1;
        }

        .header h1 {
            display: inline-flex;
            align-items: center;
            gap: 12px;
            font-family: "Noto Serif TC", "新細明體", "PMingLiU", serif;
            font-weight: 800;
            font-size: 32px;
            letter-spacing: 1.2px;
            line-height: 1.3;
            color: white;
        }

        .header .hero-emoji {
            font-size: 34px;
            filter: none;
            -webkit-text-fill-color: initial;
        }

        .header .hero-text {
            background: none;
            -webkit-background-clip: initial;
            background-clip: initial;
            -webkit-text-fill-color: white;
            color: white;
            filter: none;
        }
        
        /* ===== Sticky統計區域（玻璃擬態）===== */
        /* v1.12.0: 滾動時整條 bar 變紫漸層 + title 縮進靠左 + 4 stats 靠右、左右間距對稱 */
        .stats {
            position: sticky;
            top: 0;
            z-index: 100;
            display: flex;
            flex-direction: column;
            padding: 25px 30px;
            background: transparent;
            border-bottom: 1px solid transparent;
            will-change: padding, background;
            transition:
                padding 0.45s cubic-bezier(0.4, 0, 0.2, 1),
                background 0.4s ease,
                box-shadow 0.4s ease,
                border-bottom-color 0.4s ease,
                backdrop-filter 0.4s ease,
                -webkit-backdrop-filter 0.4s ease;
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
            transition: gap 0.45s cubic-bezier(0.4, 0, 0.2, 1);
        }

        /* v1.14.0: revert v1.12 white-on-purple → 改回 purple-on-white（白色 scrolled bar + 紫色 title） */
        /* v1.16.0: title 改用 header 同款 Noto Serif TC，整體字體調性一致 */
        .stats-title-compact {
            display: none;
            align-items: center;
            gap: 10px;
            color: #6d28d9;
            font-family: "Noto Serif TC", "新細明體", "PMingLiU", serif;
            font-weight: 900;
            font-size: 19px;
            letter-spacing: 1px;
            white-space: nowrap;
        }

        .stats-title-compact .compact-emoji {
            font-size: 20px;
            -webkit-text-fill-color: initial;
        }

        /* v1.14.0: revert v1.12 紫色漸層 bar → 改回 v1.10 風格白玻璃 bar */
        /* v1.15.0: 拿掉 space-between，stats-grid 用 flex:1 + justify-center 讓 4 格在 title 之外的空白置中 */
        .stats.scrolled {
            flex-direction: row;
            align-items: center;
            padding: 12px 30px;
            background: rgba(255, 255, 255, 0.82);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            box-shadow: 0 4px 30px rgba(102, 126, 234, 0.18);
            border-bottom-color: rgba(255, 255, 255, 0.4);
        }

        .stats.scrolled .stats-title-compact {
            display: flex;
        }

        /* v1.15.0: stats-grid 接管除 title 外的空白並 center 4 格 */
        .stats.scrolled .stats-grid {
            display: flex;
            flex: 1;
            justify-content: center;
            gap: 0;
        }

        /* v1.12.0: position relative；v1.13.0 後 progress-bar 已移除但保留以備未來 absolute child */
        /* v1.18.0: border opacity 0.5→0.7、box-shadow 微調強化 edge 感 */
        .stat-item {
            position: relative;
            text-align: center;
            padding: 18px;
            background: rgba(255, 255, 255, 0.75);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            border-radius: 20px;
            border: 1.5px solid rgba(255, 255, 255, 0.7);
            box-shadow:
                0 6px 20px rgba(102, 126, 234, 0.1),
                0 12px 36px rgba(102, 126, 234, 0.18),
                inset 0 1px 0 rgba(255, 255, 255, 0.9);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 4px;
            will-change: padding, transform, color;
            transition:
                padding 0.45s cubic-bezier(0.4, 0, 0.2, 1),
                background-color 0.4s ease,
                box-shadow 0.4s ease,
                border-color 0.4s ease,
                border-radius 0.4s ease,
                transform 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                color 0.4s ease;
        }

        .stat-item:hover {
            transform: translateY(-2px);
            box-shadow:
                0 12px 40px rgba(102, 126, 234, 0.2),
                inset 0 1px 0 rgba(255, 255, 255, 0.8);
        }

        /* v1.15.0: 白色 scrolled bar 上的 stat-item，加回 | 分隔線（border-right 1px 淡紫）*/
        .stats.scrolled .stat-item {
            background-color: transparent;
            backdrop-filter: blur(0px);
            -webkit-backdrop-filter: blur(0px);
            box-shadow:
                0 0 0 rgba(102, 126, 234, 0),
                inset 0 1px 0 rgba(255, 255, 255, 0);
            border-color: transparent;
            border-right: 1px solid rgba(102, 126, 234, 0.3);
            padding: 4px 20px;
            border-radius: 0;
            flex-direction: row;
            gap: 8px;
            margin-right: 0;
            color: inherit;
        }

        .stats.scrolled .stat-item:hover {
            transform: none;
        }

        .stats.scrolled .stat-item:last-child {
            border-right: none;
        }

        .stat-item.highlight {
            transform: translateY(-4px) scale(1.02);
            box-shadow:
                0 16px 48px rgba(102, 126, 234, 0.25),
                inset 0 1px 0 rgba(255, 255, 255, 0.9);
        }

        .stats.scrolled .stat-item.highlight {
            transform: none;
            box-shadow: none;
        }

        .stat-number {
            font-size: 42px;
            font-weight: bold;
            color: #667eea;
            display: inline-block;
            margin-bottom: 8px;
            white-space: nowrap;
            transition:
                font-size 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                margin 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                color 0.4s ease;
        }

        /* v1.14.0: revert — 白色 scrolled bar 上 stat-number 用原本紫色（保留 inline 著色的 128/34/73.4%） */
        .stats.scrolled .stat-number {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: 0;
            color: #667eea;
        }

        .stat-label {
            font-size: 14px;
            color: #6c757d;
            font-weight: 500;
            display: inline-block;
            white-space: nowrap;
            transition:
                font-size 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                color 0.4s ease;
        }

        /* v1.14.0: revert label color to grey (matches v1.10 style on white bar) */
        .stats.scrolled .stat-label {
            font-size: 14px;
            color: #6c757d;
        }

        /* v1.13.0: progress-bar 元素已移除（在「已修學分」格下方的小 bar），對應 CSS 一併清掉 */
        
        
        /* ===== v2.0.2: 響應式（手機實測修正）===== */
        /* 註：舊 @media 寫 .stats { grid-template-columns } 已失效（.stats 自 v1.12 改 flex），
           真正的 grid 是 .stats-grid */

        /* header 標題 — 手機縮字，避免 11 字標題斷成兩行 */
        @media (max-width: 600px) {
            .header {
                padding: 24px 16px 20px;
            }
            .header h1 {
                font-size: 25px;
                letter-spacing: 0.5px;
                gap: 9px;
            }
            .header .hero-emoji {
                font-size: 26px;
            }
        }
        @media (max-width: 380px) {
            .header h1 {
                font-size: 22px;
            }
        }

        /* 一般 stats — 窄螢幕 4 格 → 2 格、字體縮小 */
        @media (max-width: 640px) {
            .stats {
                padding: 18px 16px;
            }
            .stats-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 12px;
            }
            .stat-item {
                padding: 14px 10px;
            }
            .stat-number {
                font-size: 33px;
            }
            .stat-label {
                font-size: 13px;
            }
        }
        @media (max-width: 430px) {
            .stat-number {
                font-size: 27px;
            }
            .stat-label {
                font-size: 12px;
            }
        }

        /* 滾動 sticky bar — 中小螢幕改「2 排」：標題列（標題 + 字級 slider）+ 數據列（4 格）。
           標題與 slider 都保留（不再隱藏），只是改成換行排版，所以直向也會「併入 bar」 */
        @media (max-width: 780px) {
            .stats.scrolled {
                flex-wrap: wrap;
                padding: 8px 14px;
                row-gap: 5px;
            }
            .stats.scrolled .stats-title-compact {
                order: 1;
                font-size: 15px;
            }
            .stats.scrolled .font-size-slider-wrap {
                order: 2;
                margin-left: auto;
            }
            .stats.scrolled .stats-grid {
                order: 3;
                flex-basis: 100%;
                justify-content: space-around;
            }
            .stats.scrolled .stat-item {
                padding: 2px 4px;
            }
            .stats.scrolled .stat-number {
                font-size: 17px;
            }
            .stats.scrolled .stat-label {
                font-size: 12px;
            }
            /* 手機 scroll 壓縮卡頓修正：font-size / padding 過渡逐幀 reflow 很重，
               手機上關掉這些過渡 → 狀態切換瞬間完成、不卡頓 */
            .stats,
            .stat-item,
            .stat-number,
            .stat-label {
                transition: none;
            }
        }
        @media (max-width: 430px) {
            .stats.scrolled .stat-number {
                font-size: 15px;
            }
            .stats.scrolled .stat-label {
                font-size: 11px;
            }
        }
        
        /* ===== 內容區域 ===== */
        .content-wrapper {
            display: flex;
            min-height: calc(100vh - 200px);
        }
        
        @media (max-width: 1199px) {
            .content-wrapper {
                flex-direction: column;
            }
        }
        
        @media (min-width: 1200px) {
            .content-wrapper {
                flex-direction: row;
            }
        }
        
        /* ===== 橫屏：左側選課區（玻璃卡片）===== */
        @media (min-width: 1200px) {
            .simulator-panel {
                width: 360px;
                flex-shrink: 0;
                margin: 15px;
                margin-right: 0;
                background: rgba(255, 255, 255, 0.8);
                backdrop-filter: blur(18px);
                -webkit-backdrop-filter: blur(18px);
                border: 1.5px solid rgba(255, 255, 255, 0.7);
                border-radius: 20px;
                position: sticky;
                top: 70px;
                max-height: calc(100vh - 100px);
                overflow: visible;
                display: flex;
                flex-direction: column;
                /* v1.12.0: 底部 mask fade，與 tree-panel 對稱 */
                /* v1.16.0: container fade 起點 220 → 280px (smoother)，sim panel mask 相應從 190 → 250px 對齊 */
                -webkit-mask-image: linear-gradient(to bottom, black 0%, black calc(100% - 250px), transparent 100%);
                mask-image: linear-gradient(to bottom, black 0%, black calc(100% - 250px), transparent 100%);
                box-shadow: 
                    0 8px 32px rgba(102, 126, 234, 0.12),
                    inset 0 1px 0 rgba(255, 255, 255, 0.8);
            }
            
            .simulator-panel-header {
                padding: 18px 20px;
                background: transparent;
                border-bottom: 1px solid rgba(102, 126, 234, 0.1);
                display: flex;
                align-items: center;
                justify-content: space-between;
                gap: 12px;
            }

            .simulator-title {
                font-size: 18px;
                font-weight: 700;
                color: #1f2937;
                display: flex;
                align-items: center;
                gap: 10px;
            }
            
            .course-grid {
                display: flex;
                flex-direction: column;
                gap: 8px;
                padding: 12px 15px 15px;
            }
        }
        
        /* 豎屏隱藏桌面版選課區 */
        @media (max-width: 1199px) {
            .simulator-panel {
                display: none;
            }
        }
        
        /* ===== 樹狀圖區域 ===== */
        /* v1.12.0: 底部 mask fade，向下滑到頁尾紫色區時白色 block 邊界自然溶入 */
        /* v1.16.0: container fade 起點從 220 → 280px (更平滑)，tree mask 相應從 90 → 150px 對齊 */
        .tree-panel {
            flex: 1;
            display: flex;
            flex-direction: column;
            transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
            -webkit-mask-image: linear-gradient(to bottom, black 0%, black calc(100% - 150px), transparent 100%);
            mask-image: linear-gradient(to bottom, black 0%, black calc(100% - 150px), transparent 100%);
            padding-bottom: 20px;
        }
        
        /* 標題列 - 玻璃擬態 */
        .tree-header {
            position: sticky;
            top: 70px;
            z-index: 50;
            padding: 15px 25px;
            margin: 15px;
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-radius: 18px;
            border: 1.5px solid rgba(255, 255, 255, 0.7);
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
            box-shadow:
                0 6px 20px rgba(102, 126, 234, 0.1),
                0 12px 36px rgba(102, 126, 234, 0.18),
                inset 0 1px 0 rgba(255, 255, 255, 0.9);
        }
        
        @media (max-width: 1199px) {
            .tree-header.floating {
                background: rgba(255, 255, 255, 0.85);
                box-shadow: 
                    0 8px 40px rgba(102, 126, 234, 0.2),
                    inset 0 1px 0 rgba(255, 255, 255, 0.9);
            }
        }
        
        @media (min-width: 1200px) {
            .tree-header {
                margin: 15px 25px 15px 15px;
                top: 70px;
            }
        }
        
        .tree-header-title {
            font-size: 18px;
            font-weight: 700;
            color: #1f2937;
            flex: 1;
            text-align: center;
        }
        
        /* v1.10.0: ghost 風格 — 透明底，hover 出現淡紫圓形 */
        .header-btn {
            width: 38px;
            height: 38px;
            padding: 0;
            background: transparent;
            color: #9ca3af;
            border: none;
            border-radius: 50%;
            font-size: 20px;
            cursor: pointer;
            transition:
                background-color 0.25s ease,
                color 0.25s ease,
                transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .header-btn:hover {
            background: rgba(102, 126, 234, 0.12);
            color: #667eea;
        }

        .header-btn.active {
            background: rgba(102, 126, 234, 0.16);
            color: #667eea;
            transform: rotate(45deg);
        }
        
        /* 橫屏隱藏選課按鈕 */
        @media (min-width: 1200px) {
            #course-btn {
                display: none;
            }
            
            .tree-header-title {
                text-align: left;
                padding-left: 10px;
            }
        }
        
        /* ===== 豎屏選課遮罩和面板（iOS Bottom Sheet 風格）===== */
        .mobile-overlay {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(4px);
            -webkit-backdrop-filter: blur(4px);
            z-index: 200;
            opacity: 0;
            visibility: hidden;
            transition: all 0.4s ease;
        }
        
        .mobile-overlay.active {
            opacity: 1;
            visibility: visible;
        }
        
        .mobile-course-panel {
            position: fixed;
            bottom: 0;
            left: 0;
            right: 0;
            max-height: 80vh;
            background: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-radius: 24px 24px 0 0;
            z-index: 250;
            transform: translateY(100%);
            transition: transform 0.5s cubic-bezier(0.32, 0.72, 0, 1);
            box-shadow: 
                0 -10px 60px rgba(0, 0, 0, 0.15),
                0 -2px 20px rgba(102, 126, 234, 0.1);
            overflow: hidden;
        }
        
        .mobile-course-panel.active {
            transform: translateY(0);
        }
        
        /* 拖曳指示器 */
        .mobile-panel-handle {
            width: 36px;
            height: 5px;
            background: rgba(0, 0, 0, 0.15);
            border-radius: 3px;
            margin: 12px auto 8px;
        }
        
        .mobile-panel-header {
            padding: 12px 20px 16px;
            display: flex;
            align-items: center;
            gap: 12px;
            border-bottom: 1px solid rgba(102, 126, 234, 0.1);
        }

        /* v1.10.0: outline + glass 風格 — 取消實心紫色 gradient */
        .select-all-btn {
            background: rgba(255, 255, 255, 0.4);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            color: #667eea;
            border: 1.5px solid rgba(102, 126, 234, 0.5);
            padding: 6px 14px;
            border-radius: 10px;
            font-size: 13px;
            font-weight: 600;
            cursor: pointer;
            transition:
                background-color 0.25s ease,
                border-color 0.25s ease,
                color 0.25s ease,
                transform 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            white-space: nowrap;
            flex-shrink: 0;
        }

        .select-all-btn:hover {
            background: rgba(102, 126, 234, 0.08);
            border-color: rgba(102, 126, 234, 0.9);
            transform: translateY(-1px);
        }

        .select-all-btn:active {
            transform: translateY(0);
        }

        /* 選中狀態用 amber 而非 red，較不刺眼 */
        .select-all-btn.selected {
            color: #f59e0b;
            border-color: rgba(245, 158, 11, 0.5);
            background: rgba(255, 255, 255, 0.4);
        }

        .select-all-btn.selected:hover {
            background: rgba(245, 158, 11, 0.08);
            border-color: rgba(245, 158, 11, 0.9);
        }

        /* v1.12.0: toggle bounce animation — 切換時瞬間 scale 下沉再彈回，視覺更明顯 */
        /* v1.13.0: 同一個 keyframes 套用到 .header-btn.toggling，全螢幕切換也有 bounce */
        .select-all-btn.toggling,
        .header-btn.toggling {
            animation: toggleBounce 0.42s cubic-bezier(0.4, 0, 0.2, 1);
        }
        @keyframes toggleBounce {
            0%   { transform: scale(1); }
            35%  { transform: scale(0.85); }
            70%  { transform: scale(1.08); }
            100% { transform: scale(1); }
        }
        /* header-btn 在 active 狀態 (.active) 有 rotate(45deg)，bounce 時用 rotateY 增強 */
        .header-btn.active.toggling {
            animation: toggleBounceRotated 0.45s cubic-bezier(0.4, 0, 0.2, 1);
        }
        @keyframes toggleBounceRotated {
            0%   { transform: rotate(0deg) scale(1); }
            35%  { transform: rotate(20deg) scale(0.85); }
            70%  { transform: rotate(50deg) scale(1.08); }
            100% { transform: rotate(45deg) scale(1); }
        }

        /* v1.12.0: B1 — theme 切換時的全域 smooth transition */
        .header,
        .footer,
        .footer-subtitle,
        .version-link,
        .header h1,
        .hero-text,
        .hero-emoji {
            transition:
                background 0.45s ease,
                background-color 0.45s ease,
                color 0.45s ease,
                border-color 0.45s ease,
                border-bottom-color 0.45s ease,
                padding 0.45s cubic-bezier(0.4, 0, 0.2, 1),
                filter 0.45s ease,
                letter-spacing 0.45s ease;
        }
        .container {
            transition: background 0.5s ease;
        }

        /* ===== v1.11.0: Classic theme overrides (pre-v1.10.0 visual) ===== */
        body.theme-classic {
            background-attachment: scroll;
        }
        body.theme-classic .header {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            padding: 25px 30px;
            -webkit-mask-image: none;
            mask-image: none;
        }
        /* v1.12.0: classic theme — h1 變回 v1.7 樣式（白色純文字、無 fancy gradient） */
        body.theme-classic .header h1 {
            font-family: "Microsoft JhengHei", "微軟正黑體", sans-serif;
            font-weight: 700;
            font-size: 32px;
            letter-spacing: normal;
        }
        body.theme-classic .header .hero-emoji {
            filter: none;
        }
        body.theme-classic .header .hero-text {
            background: none;
            -webkit-background-clip: initial;
            background-clip: initial;
            -webkit-text-fill-color: white;
            color: white;
            filter: none;
        }
        /* v1.12.0: classic theme — sticky scrolled bar 維持 v1.7 白色玻璃，不變紫漸層 */
        body.theme-classic .stats.scrolled {
            background: rgba(255, 255, 255, 0.75);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            box-shadow: 0 4px 30px rgba(102, 126, 234, 0.15);
            border-bottom-color: rgba(255, 255, 255, 0.3);
        }
        body.theme-classic .stats.scrolled .stats-title-compact {
            color: #1f2937;
            font-family: "Microsoft JhengHei", "微軟正黑體", sans-serif;
            font-weight: 700;
        }
        body.theme-classic .stats.scrolled .stat-item {
            color: inherit;
            border-right-color: rgba(102, 126, 234, 0.2);
        }
        body.theme-classic .stats.scrolled .stat-number {
            color: #667eea !important;
        }
        body.theme-classic .stats.scrolled .stat-label {
            color: #6c757d;
        }
        body.theme-classic .stats.scrolled .stat-number[style*="ef4444"] { color: #ef4444 !important; }
        body.theme-classic .stats.scrolled .stat-number[style*="f59e0b"] { color: #f59e0b !important; }
        body.theme-classic .stats.scrolled .stat-number[style*="10b981"] { color: #10b981 !important; }

        /* ===== v1.13.0: v1-10 theme overrides (post-v1.10, pre-v1.12 visual) ===== */
        /* 還原：透明 header 紫漸層、簡單 h1、白玻璃 scrolled bar、無 title morph、無 mask fade、星空 0.7 */
        body.theme-v1-10 .container {
            background:
                linear-gradient(
                    180deg,
                    transparent 0px,
                    transparent 200px,
                    #f8f9fa 320px,
                    #f8f9fa calc(100% - 220px),
                    transparent calc(100% - 100px),
                    transparent 100%
                );
        }
        body.theme-v1-10 .header {
            background: transparent;
            padding: 35px 30px 30px;
            -webkit-mask-image: none;
            mask-image: none;
        }
        body.theme-v1-10 .header h1 {
            font-family: "Microsoft JhengHei", "微軟正黑體", sans-serif;
            font-weight: 700;
            font-size: 32px;
            letter-spacing: normal;
        }
        body.theme-v1-10 .header .hero-emoji {
            filter: none;
        }
        body.theme-v1-10 .header .hero-text {
            background: none;
            -webkit-background-clip: initial;
            background-clip: initial;
            -webkit-text-fill-color: white;
            color: white;
            filter: none;
        }
        body.theme-v1-10 #stellar-bg {
            opacity: 0.7;
        }
        body.theme-v1-10 .tree-panel,
        body.theme-v1-10 .simulator-panel {
            -webkit-mask-image: none;
            mask-image: none;
        }
        body.theme-v1-10 .stats.scrolled {
            background: rgba(255, 255, 255, 0.75);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            box-shadow: 0 4px 30px rgba(102, 126, 234, 0.15);
            border-bottom-color: rgba(255, 255, 255, 0.3);
            padding: 10px 20px;
        }
        body.theme-v1-10 .stats.scrolled .stats-title-compact {
            display: none;
        }
        body.theme-v1-10 .stats.scrolled .stat-item {
            color: inherit;
            border-right-color: rgba(102, 126, 234, 0.2);
            border-right-width: 2px;
            padding: 5px 20px 5px 0;
        }
        body.theme-v1-10 .stats.scrolled .stat-item:first-child {
            padding-left: 0;
        }
        body.theme-v1-10 .stats.scrolled .stat-item:last-child {
            border-right-color: transparent;
            padding-right: 0;
        }
        body.theme-v1-10 .stats.scrolled .stat-number {
            color: #667eea !important;
            font-size: 18px;
        }
        body.theme-v1-10 .stats.scrolled .stat-label {
            color: #6c757d;
            font-size: 12px;
        }
        body.theme-v1-10 .stats.scrolled .stat-number[style*="ef4444"] { color: #ef4444 !important; }
        body.theme-v1-10 .stats.scrolled .stat-number[style*="f59e0b"] { color: #f59e0b !important; }
        body.theme-v1-10 .stats.scrolled .stat-number[style*="10b981"] { color: #10b981 !important; }
        body.theme-classic .container {
            background: #f8f9fa;
        }
        body.theme-classic .footer {
            background: rgba(248, 249, 250, 0.9);
            padding: 25px;
            color: #6c757d;
            border-top: 1px solid rgba(0, 0, 0, 0.05);
        }
        body.theme-classic .footer kbd {
            background: #e5e7eb;
            color: inherit;
            border: none;
        }
        body.theme-classic .footer-subtitle {
            color: #9ca3af;
        }
        body.theme-classic .version-link {
            color: #667eea;
            border-bottom-color: rgba(102, 126, 234, 0.4);
        }
        body.theme-classic .version-link:hover {
            color: #764ba2;
            border-bottom-color: rgba(118, 75, 162, 0.6);
        }
        body.theme-classic #stellar-bg {
            opacity: 0.6;
        }
        body.theme-classic .select-all-btn {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            padding: 7px 14px;
            box-shadow: 0 4px 12px rgba(102, 126, 234, 0.25);
            backdrop-filter: none;
            -webkit-backdrop-filter: none;
        }
        body.theme-classic .select-all-btn:hover {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-color: transparent;
            transform: translateY(-2px);
            box-shadow: 0 6px 18px rgba(102, 126, 234, 0.4);
        }
        body.theme-classic .select-all-btn.selected {
            background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
            color: white;
            border-color: transparent;
            box-shadow: 0 4px 12px rgba(239, 68, 68, 0.25);
        }
        body.theme-classic .select-all-btn.selected:hover {
            background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
            border-color: transparent;
            box-shadow: 0 6px 18px rgba(239, 68, 68, 0.4);
        }
        body.theme-classic .header-btn {
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border-radius: 12px;
            font-size: 16px;
            box-shadow: 0 2px 10px rgba(102, 126, 234, 0.3);
        }
        body.theme-classic .header-btn:hover {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
        }
        body.theme-classic .header-btn.active {
            background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
            color: white;
            transform: rotate(45deg);
            box-shadow: 0 2px 10px rgba(102, 126, 234, 0.3);
        }

        /* footer subtitle — class form so theme-classic can override color */
        .footer-subtitle {
            margin-top: 5px;
            font-size: 11px;
            color: rgba(255, 255, 255, 0.65);
        }

        /* Theme switcher button inside Changelog modal */
        .theme-switch-btn {
            margin-top: 12px;
            padding: 6px 12px;
            font-size: 12px;
            font-weight: 600;
            border-radius: 8px;
            background: rgba(102, 126, 234, 0.08);
            color: #667eea;
            border: 1px solid rgba(102, 126, 234, 0.3);
            cursor: pointer;
            transition:
                background-color 0.2s ease,
                border-color 0.2s ease,
                color 0.2s ease;
            float: right;
        }
        .theme-switch-btn:hover {
            background: rgba(102, 126, 234, 0.16);
            border-color: rgba(102, 126, 234, 0.6);
        }
        .theme-switch-btn.active {
            background: rgba(16, 185, 129, 0.12);
            color: #059669;
            border-color: rgba(16, 185, 129, 0.4);
            cursor: default;
            pointer-events: none;
        }

        /* ===== Changelog Modal ===== */
        /* v1.10.0: footer 改紫底，version link 改白色 */
        .version-link {
            color: rgba(255, 255, 255, 0.95);
            text-decoration: none;
            font-weight: 600;
            transition: all 0.2s ease;
            border-bottom: 1px dashed rgba(255, 255, 255, 0.4);
            cursor: pointer;
        }

        .version-link:hover {
            color: white;
            border-bottom-color: rgba(255, 255, 255, 0.8);
        }

        /* v1.17.0: 字體大小 slider — 位於 sticky bar 右側，僅 scrolled 時顯示 */
        .font-size-slider-wrap {
            display: none;
            align-items: center;
            gap: 8px;
            flex-shrink: 0;
        }
        .stats.scrolled .font-size-slider-wrap {
            display: flex;
        }
        .slider-icon {
            color: rgba(102, 126, 234, 0.75);
            font-weight: 700;
            font-family: "Noto Serif TC", "新細明體", serif;
            user-select: none;
        }
        .slider-icon-small { font-size: 11px; }
        .slider-icon-large { font-size: 17px; }
        body.theme-classic .slider-icon,
        body.theme-v1-10 .slider-icon {
            color: rgba(102, 126, 234, 0.75);
        }

        .font-size-slider {
            -webkit-appearance: none;
            appearance: none;
            width: 90px;
            height: 5px;
            border-radius: 4px;
            background: linear-gradient(
                to right,
                #6d28d9 0%,
                #6d28d9 var(--slider-fill, 30%),
                rgba(102, 126, 234, 0.22) var(--slider-fill, 30%),
                rgba(102, 126, 234, 0.22) 100%
            );
            outline: none;
            cursor: pointer;
            transition: filter 0.2s ease;
        }
        .font-size-slider:hover {
            filter: brightness(1.05);
        }
        .font-size-slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            appearance: none;
            width: 14px;
            height: 14px;
            background: white;
            border: 2px solid #6d28d9;
            border-radius: 50%;
            cursor: grab;
            box-shadow: 0 2px 6px rgba(102, 126, 234, 0.4);
            transition: transform 0.15s ease, box-shadow 0.15s ease;
        }
        .font-size-slider::-webkit-slider-thumb:hover {
            transform: scale(1.18);
            box-shadow: 0 3px 10px rgba(102, 126, 234, 0.55);
        }
        .font-size-slider::-webkit-slider-thumb:active {
            cursor: grabbing;
            transform: scale(1.25);
        }
        .font-size-slider::-moz-range-thumb {
            width: 14px;
            height: 14px;
            background: white;
            border: 2px solid #6d28d9;
            border-radius: 50%;
            cursor: grab;
            box-shadow: 0 2px 6px rgba(102, 126, 234, 0.4);
        }

        .changelog-overlay {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(4px);
            -webkit-backdrop-filter: blur(4px);
            z-index: 1500;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.4s cubic-bezier(0.32, 0.72, 0, 1), visibility 0.4s;
        }

        .changelog-overlay.active {
            opacity: 1;
            visibility: visible;
        }

        .changelog-modal {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -45%) scale(0.95);
            width: 90%;
            max-width: 640px;
            max-height: 85vh;
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-radius: 24px;
            border: 1px solid rgba(255, 255, 255, 0.5);
            box-shadow: 0 20px 60px rgba(102, 126, 234, 0.25);
            z-index: 1501;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.45s cubic-bezier(0.32, 0.72, 0, 1), visibility 0.45s, transform 0.45s cubic-bezier(0.32, 0.72, 0, 1);
            overflow: hidden;
            display: flex;
            flex-direction: column;
        }

        .changelog-modal.active {
            opacity: 1;
            visibility: visible;
            transform: translate(-50%, -50%) scale(1);
        }

        .changelog-header {
            padding: 20px 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            border-bottom: 1px solid rgba(102, 126, 234, 0.1);
            background: linear-gradient(135deg, rgba(102, 126, 234, 0.05), rgba(118, 75, 162, 0.05));
            flex-shrink: 0;
        }

        .changelog-header h2 {
            font-size: 20px;
            font-weight: 700;
            color: #1f2937;
        }

        .changelog-header p {
            font-size: 13px;
            color: #6b7280;
            margin-top: 2px;
        }

        .changelog-close-btn {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.7);
            border: 1px solid rgba(102, 126, 234, 0.15);
            color: #6b7280;
            font-size: 16px;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .changelog-close-btn:hover {
            background: rgba(239, 68, 68, 0.1);
            color: #ef4444;
            transform: rotate(90deg);
        }

        .changelog-content {
            padding: 20px 24px 24px;
            overflow-y: auto;
            flex: 1;
        }

        .changelog-entry {
            padding: 18px;
            background: rgba(255, 255, 255, 0.7);
            border: 1px solid rgba(102, 126, 234, 0.12);
            border-radius: 16px;
            margin-bottom: 14px;
            transition: all 0.3s ease;
        }

        .changelog-entry:hover {
            transform: translateX(2px);
            box-shadow: 0 4px 16px rgba(102, 126, 234, 0.1);
        }

        .changelog-entry:last-child {
            margin-bottom: 0;
        }

        .changelog-version-row {
            display: flex;
            align-items: baseline;
            gap: 12px;
            margin-bottom: 10px;
            padding-bottom: 10px;
            border-bottom: 1px dashed rgba(102, 126, 234, 0.15);
        }

        .changelog-version {
            font-size: 18px;
            font-weight: 700;
            background: linear-gradient(135deg, #667eea, #764ba2);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .changelog-date {
            font-size: 12px;
            color: #9ca3af;
        }

        .changelog-tag {
            margin-left: auto;
            padding: 2px 10px;
            border-radius: 8px;
            font-size: 11px;
            font-weight: 700;
            letter-spacing: 0.3px;
        }

        .changelog-tag.major {
            background: rgba(239, 68, 68, 0.1);
            color: #dc2626;
        }

        .changelog-tag.minor {
            background: rgba(102, 126, 234, 0.1);
            color: #4f46e5;
        }

        .changelog-tag.patch {
            background: rgba(16, 185, 129, 0.1);
            color: #059669;
        }

        .changelog-list {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .changelog-list li {
            padding: 6px 0 6px 22px;
            position: relative;
            font-size: 14px;
            color: #4b5563;
            line-height: 1.5;
        }

        .changelog-list li::before {
            content: '▸';
            position: absolute;
            left: 6px;
            color: #667eea;
            font-weight: 700;
        }

        /* v1.16.0: changelog markup styling — strong / u / em */
        .changelog-list li strong {
            color: #1f2937;
            font-weight: 700;
        }
        .changelog-list li u {
            text-decoration: underline;
            text-decoration-color: rgba(102, 126, 234, 0.55);
            text-underline-offset: 3px;
            text-decoration-thickness: 1.5px;
        }
        .changelog-list li em {
            font-style: italic;
            color: #6d28d9;
        }

        .mobile-panel-header-icon {
            width: 44px;
            height: 44px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 14px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
        }
        
        .mobile-panel-header h3 {
            font-size: 18px;
            font-weight: 700;
            color: #1f2937;
        }
        
        .mobile-panel-header p {
            font-size: 13px;
            color: #6b7280;
            margin-top: 2px;
        }
        
        .mobile-panel-content {
            padding: 16px;
            max-height: calc(80vh - 100px);
            overflow-y: auto;
            padding-bottom: max(16px, env(safe-area-inset-bottom));
        }
        
        .mobile-course-grid {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        
        .mobile-course-item {
            opacity: 0;
            transform: translateY(20px) scale(0.95);
            transition: all 0.4s cubic-bezier(0.32, 0.72, 0, 1);
        }
        
        .mobile-course-panel.active .mobile-course-item {
            opacity: 1;
            transform: translateY(0) scale(1);
        }
        
        /* 依序延遲動畫 - 更快的節奏 */
        .mobile-course-item:nth-child(1) { transition-delay: 0.05s; }
        .mobile-course-item:nth-child(2) { transition-delay: 0.08s; }
        .mobile-course-item:nth-child(3) { transition-delay: 0.11s; }
        .mobile-course-item:nth-child(4) { transition-delay: 0.14s; }
        .mobile-course-item:nth-child(5) { transition-delay: 0.17s; }
        .mobile-course-item:nth-child(6) { transition-delay: 0.20s; }
        .mobile-course-item:nth-child(7) { transition-delay: 0.23s; }
        .mobile-course-item:nth-child(8) { transition-delay: 0.26s; }
        .mobile-course-item:nth-child(9) { transition-delay: 0.29s; }
        
        @media (min-width: 1200px) {
            .mobile-overlay,
            .mobile-course-panel {
                display: none !important;
            }
        }
        
        /* 共用課程項目樣式（玻璃風格）*/
        .course-item-sim {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 12px 14px;
            background: rgba(255, 255, 255, 0.6);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            border: 1px solid rgba(255, 255, 255, 0.8);
            border-radius: 12px;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            box-shadow: 0 2px 8px rgba(102, 126, 234, 0.06);
        }
        
        .course-item-sim:hover {
            background: rgba(255, 255, 255, 0.85);
            transform: translateY(-2px);
            box-shadow: 0 4px 16px rgba(102, 126, 234, 0.12);
            border-color: rgba(102, 126, 234, 0.3);
        }
        
        .course-item-sim.selected {
            background: linear-gradient(135deg, rgba(219, 234, 254, 0.9), rgba(191, 219, 254, 0.9));
            border-color: rgba(102, 126, 234, 0.4);
            box-shadow: 0 4px 20px rgba(102, 126, 234, 0.2);
        }
        
        .course-item-sim.selected .course-name-sim {
            color: #4338ca;
        }
        
        .course-item-sim input[type="checkbox"] {
            width: 18px;
            height: 18px;
            cursor: pointer;
            accent-color: #667eea;
        }
        
        .course-name-sim {
            flex: 1;
            font-size: 14px;
            font-weight: 500;
            color: #1f2937;
        }
        
        .course-credits-sim {
            font-size: 13px;
            color: #667eea;
            font-weight: 600;
        }
        
        /* ===== 樹狀圖內容 ===== */
        #tree-container {
            flex: 1;
            padding: 5px 25px 40px;
            overflow-x: hidden;
        }
        
        @media (max-width: 1199px) {
            #tree-container {
                padding: 5px 15px 40px;
            }
        }
        
        .tree {
            padding-left: 0;
            list-style: none;
        }
        
        .tree-node {
            position: relative;
            padding: 4px 0;
        }
        
        .node-content {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 12px 16px;
            background: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            border-radius: 14px;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            border: 1.5px solid rgba(255, 255, 255, 0.8);
            box-shadow:
                0 2px 8px rgba(102, 126, 234, 0.06),
                0 4px 16px rgba(102, 126, 234, 0.08);
            margin-right: 5px;
        }
        
        .node-content:hover {
            transform: translateX(4px);
            background: rgba(255, 255, 255, 0.95);
            box-shadow: 0 4px 20px rgba(102, 126, 234, 0.12);
            border-color: rgba(102, 126, 234, 0.3);
        }
        
        .node-icon {
            width: 28px;
            height: 28px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 13px;
            font-weight: bold;
            color: white;
            flex-shrink: 0;
        }
        
        .status-completed { background: linear-gradient(135deg, #10b981, #059669); }
        .status-partial { background: linear-gradient(135deg, #f59e0b, #d97706); }
        .status-incomplete { background: linear-gradient(135deg, #ef4444, #dc2626); }
        
        .node-label {
            flex: 1;
            font-weight: 600;
            color: #1f2937;
            font-size: 15px;
        }
        
        .node-credits {
            display: flex;
            gap: 4px;
            align-items: center;
            font-size: 14px;
        }
        
        .credits-earned {
            color: #10b981;
            font-weight: 700;
        }
        
        .credits-required {
            color: #9ca3af;
        }
        
        .toggle-icon {
            width: 24px;
            height: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #9ca3af;
            transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
            font-size: 14px;
        }
        
        .toggle-icon.expanded {
            transform: rotate(90deg);
        }
        
        /* 樹狀連接線 + 展開動畫（Apple/Stripe風格）*/
        .tree-children {
            list-style: none;
            padding-left: 20px;
            margin-left: 14px;
            border-left: 2px solid #e5e7eb;
            display: grid;
            grid-template-rows: 0fr;
            opacity: 0;
            transition: grid-template-rows 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                        opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                        padding 0.4s cubic-bezier(0.4, 0, 0.2, 1);
            padding-top: 0;
            padding-bottom: 0;
        }
        
        .tree-children > .tree-children-inner {
            overflow: hidden;
        }

        .tree-children.show {
            grid-template-rows: 1fr;
            opacity: 1;
            padding-top: 8px;
            padding-bottom: 8px;
        }

        /* v1.17.0: course-section 包裝層 — 用 grid-template-rows 動畫做 expand/collapse */
        /* 取代 v1.16 的 fade-in flicker；section 第一次出現/消失時平滑展開/收合 */
        .course-section {
            display: grid;
            grid-template-rows: 0fr;
            transition:
                grid-template-rows 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                opacity 0.32s ease;
            opacity: 0;
        }
        .course-section > .course-section-inner {
            overflow: hidden;
        }
        .course-section.show {
            grid-template-rows: 1fr;
            opacity: 1;
        }
        
        /* 水平連接線 */
        .tree-children > .tree-children-inner > .tree-node {
            position: relative;
        }
        
        .tree-children > .tree-children-inner > .tree-node::before {
            content: '';
            position: absolute;
            left: -20px;
            top: 26px;
            width: 18px;
            height: 2px;
            background: #e5e7eb;
        }
        
        /* 已修課程摺疊區塊 */
        .completed-summary {
            padding: 10px 14px;
            margin: 4px 5px 4px 30px;
            border-radius: 8px;
            font-size: 13px;
            background: linear-gradient(135deg, #d1fae5, #a7f3d0);
            border-left: 3px solid #10b981;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: all 0.3s ease;
        }
        
        .completed-summary:hover {
            background: linear-gradient(135deg, #a7f3d0, #6ee7b7);
        }
        
        .completed-summary-text {
            font-weight: 600;
            color: #065f46;
        }
        
        .completed-summary-toggle {
            color: #059669;
            font-size: 12px;
            transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        }
        
        .completed-summary-toggle.expanded {
            transform: rotate(180deg);
        }
        
        .completed-courses-list {
            display: grid;
            grid-template-rows: 0fr;
            transition: grid-template-rows 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        }
        
        .completed-courses-list > .completed-courses-inner {
            overflow: hidden;
        }
        
        .completed-courses-list.show {
            grid-template-rows: 1fr;
        }
        
        .course-detail {
            padding: 10px 14px;
            margin: 4px 5px 4px 30px;
            border-radius: 8px;
            font-size: 13px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: all 0.2s ease;
        }
        
        .course-detail.completed {
            background: linear-gradient(135deg, #ecfdf5, #d1fae5);
            border-left: 3px solid #10b981;
        }
        
        .course-detail.available {
            background: #f3f4f6;
            border-left: 3px solid #9ca3af;
        }
        
        .course-detail.new {
            background: linear-gradient(135deg, #dbeafe, #bfdbfe);
            border-left: 3px solid #3b82f6;
        }
        
        .course-info {
            display: flex;
            gap: 8px;
            align-items: center;
            flex-wrap: wrap;
        }
        
        .course-tag {
            font-size: 11px;
            padding: 3px 8px;
            border-radius: 12px;
            font-weight: 600;
        }
        
        .tag-grade {
            background: #10b981;
            color: white;
        }
        
        .tag-semester {
            background: #e5e7eb;
            color: #4b5563;
        }
        
        .tag-new {
            background: #3b82f6;
            color: white;
        }
        
        .section-header {
            font-size: 11px;
            font-weight: 700;
            color: #6b7280;
            margin: 10px 0 6px 30px;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }
        
        .badge {
            display: inline-block;
            padding: 4px 10px;
            border-radius: 12px;
            font-size: 11px;
            font-weight: 600;
            margin-left: 8px;
        }
        
        .badge-warning { background: #fef3c7; color: #92400e; }
        .badge-danger { background: #fee2e2; color: #991b1b; }
        .badge-info { background: #dbeafe; color: #1e40af; }
        
        /* 全螢幕模式 + 動畫 */
        .tree-panel {
            transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
        }
        
        .tree-panel.fullscreen {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            z-index: 999;
            background-color: #f8f9fa;
            border-radius: 0;
            overflow-y: auto;
            overflow-x: hidden;
        }
        
        /* 全螢幕時 canvas 在 tree-panel 內部最底層 */
        .tree-panel.fullscreen #stellar-bg {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: 0;
            pointer-events: none;
        }
        
        /* 全螢幕時 tree-container 在 canvas 之上 */
        .tree-panel.fullscreen #tree-container {
            position: relative;
            z-index: 1;
        }
        
        /* 全螢幕時隱藏其他元素 */
        body.fullscreen-mode .stats,
        body.fullscreen-mode .header,
        body.fullscreen-mode .footer,
        body.fullscreen-mode .simulator-panel {
            display: none !important;
        }
        
        /* 全螢幕時選課面板層級調整 */
        body.fullscreen-mode .mobile-overlay {
            z-index: 1000;
        }
        
        body.fullscreen-mode .mobile-course-panel {
            z-index: 1001;
        }
        
        .tree-panel.fullscreen .tree-header {
            position: relative;
            z-index: 2;
            top: 15px;
            margin: 15px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            box-shadow: 0 4px 25px rgba(102, 126, 234, 0.3);
            backdrop-filter: none;
            -webkit-backdrop-filter: none;
        }
        
        .tree-panel.fullscreen .node-content {
            background: white;
            backdrop-filter: none;
            -webkit-backdrop-filter: none;
            border: 1px solid rgba(0, 0, 0, 0.08);
        }
        
        .tree-panel.fullscreen .completed-summary {
            background: linear-gradient(135deg, #ecfdf5, #d1fae5);
            backdrop-filter: none;
            -webkit-backdrop-filter: none;
        }
        
        .tree-panel.fullscreen .course-detail {
            background: white;
        }
        
        .tree-panel.fullscreen .course-detail.completed {
            background: linear-gradient(135deg, #ecfdf5, #d1fae5);
        }
        
        .tree-panel.fullscreen .course-detail.new {
            background: linear-gradient(135deg, #dbeafe, #bfdbfe);
        }
        
        .tree-panel.fullscreen .course-detail.available {
            background: #f3f4f6;
        }
        
        .tree-panel.fullscreen .tree-header-title {
            color: white;
        }
        
        .tree-panel.fullscreen .header-btn {
            background: rgba(255,255,255,0.2);
            border: 1px solid rgba(255,255,255,0.3);
            box-shadow: none;
        }
        
        /* v1.10.0: footer 透明，融入 body 紫色 gradient + 星空 */
        /* v1.18.0: padding 縮小 (40/25/50 → 18/25/24)、字略小 13→12 */
        .footer {
            background: transparent;
            padding: 18px 25px 24px;
            text-align: center;
            color: rgba(255, 255, 255, 0.85);
            font-size: 12px;
            border-top: none;
        }

        .footer kbd {
            background: rgba(255, 255, 255, 0.2);
            color: rgba(255, 255, 255, 0.95);
            padding: 2px 6px;
            border-radius: 4px;
            font-size: 11px;
            border: 1px solid rgba(255, 255, 255, 0.25);
        }
        
        /* 快捷鍵提示 */
        .shortcut-hint {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background: rgba(0,0,0,0.8);
            color: white;
            padding: 12px 18px;
            border-radius: 12px;
            font-size: 13px;
            z-index: 1000;
            opacity: 0;
            transform: translateY(10px);
            transition: all 0.3s ease;
            pointer-events: none;
        }
        
        .shortcut-hint.show {
            opacity: 1;
            transform: translateY(0);
        }