:root {
    --bg-dark: #0f172a;
    --bg-secondary: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-primary: #38bdf8;
    /* Light Blue */
    --accent-secondary: #818cf8;
    /* Indigo */
    --accent-gradient: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --sidebar-width: 260px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', 'Noto Sans TC', sans-serif;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    /* Force Mobile App Layout */
    max-width: 480px;
    margin: 0 auto;
    min-height: 100vh;
    border-left: 1px solid var(--glass-border);
    border-right: 1px solid var(--glass-border);
    box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
    overflow-x: hidden;
    position: relative;
}

/* Layout */
.app-container {
    display: block;
    width: 100%;
    height: 100%;
}

/* Bottom Nav - Always Visible */
.bottom-nav {
    display: flex !important;
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 480px;
    background: rgba(30, 41, 59, 0.95);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--glass-border);
    justify-content: space-around;
    padding: 1rem 0;
    z-index: 1000;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.2);
    border-radius: 20px 20px 0 0;
}

/* Navigation Items */
.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.3rem;
    color: var(--text-secondary);
    font-size: 0.8rem;
    cursor: pointer;
    transition: color 0.3s;
}

.nav-item i {
    font-size: 1.4rem;
}

.nav-item.active {
    color: var(--accent-primary);
}

.nav-item.active i {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Floating Action Button (FAB) for adding books */
.fab-add {
    position: fixed;
    bottom: 90px;
    right: 20px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--accent-gradient);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 4px 15px rgba(56, 189, 248, 0.4);
    border: none;
    z-index: 999;
    cursor: pointer;
}

/* 舊版這裡是 height:300px !important + overflow:hidden，
   會把文字雲鎖死在固定高度、超出的字直接看不見。
   改用 min-height 讓它隨標籤數量長高。 */

h1 {
    font-size: 1.8rem;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
    background: radial-gradient(circle at top right, #1e1b4b 0%, var(--bg-dark) 40%);
    margin-left: 0;
    width: 100%;
    padding: 1.5rem;
    padding-bottom: 120px;   /* 讓開底部導覽列 */
}

.top-bar {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 2rem 3rem;
    align-items: center;
    justify-content: space-between;
}

.top-bar h1 {
    font-size: 2rem;
    font-weight: 600;
}

.search-bar {
    display: flex;
    align-items: center;
    background: var(--glass-bg);
    padding: 0.8rem 1.5rem;
    border-radius: 50px;
    border: 1px solid var(--glass-border);
    /* 用 max-width 不用固定 width：窄畫面時容器只有約 342px，
       寫死 400px 會超出並被 .main-content 的 overflow:hidden 切掉一截。
       （舊版有一條 width:100% 想處理這件事，但被下面的 400px 蓋掉了） */
    width: 100%;
    max-width: 400px;
    gap: 10px;
}

.search-bar input {
    background: transparent;
    border: none;
    color: var(--text-primary);
    width: 100%;
    outline: none;
    font-size: 1rem;
}

.search-bar i {
    color: var(--text-secondary);
}

/* View Container */
.view-container {
    flex: 1;
    overflow-y: auto;
    /* 左右各 1.5rem。原本是 3rem，但 body 已經被 max-width:480px 夾住，
       再吃掉 96px 會讓內容只剩 334px。 */
    padding: 0 1.5rem 1.5rem 1.5rem;
}

/* Dashboard Widgets */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* Book Grid */
/* 一排一本。
   minmax(0, 1fr) 的 0 不能省 —— 預設最小值是 auto，
   長書名會把軌道撐開造成整頁橫向捲動。 */
.book-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 1rem;
}

/* flex column + 日期 margin-top:auto，讓同一列的卡片
   不管內容多寡，日期都對齊在底部 */
.book-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1.25rem;
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    border-color: var(--accent-primary);
}

.book-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent-gradient);
    opacity: 0;
    transition: opacity 0.3s;
}

.book-card:hover::before {
    opacity: 1;
}

/* 摘要固定 3 行。不截斷的話長心得會讓某些卡片高到誇張，
   一頁看不到幾本。書名截 2 行，避免超長書名把卡片撐開。 */
.book-title {
    font-size: 1.1rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 0.6rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    overflow-wrap: anywhere;
}

.book-domain {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-bottom: 0.75rem;
}

.book-summary {
    font-size: 0.9rem;
    color: #cbd5e1;
    line-height: 1.6;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    overflow-wrap: anywhere;
}

.book-date {
    margin-top: auto;
    padding-top: 0.9rem;
    font-size: 0.75rem;
    color: #64748b;
}

.book-status {
    font-size: 0.85rem;
    color: #94a3b8;
    line-height: 1.5;
}

.book-status.failed {
    color: #fbbf24;
}

.book-card-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.6rem;
}

.book-card-actions button {
    padding: 0.45rem 0.9rem;
    min-height: 38px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.8rem;
    white-space: nowrap;
    background: transparent;
}

.book-card-actions .retry {
    color: #fbbf24;
    border: 1px solid #fbbf24;
    background: rgba(251, 191, 36, 0.12);
}

.book-card-actions .keyfix {
    color: #94a3b8;
    border: 1px solid #334155;
}

/* 卡片上的小型標籤（沿用主題頁的 .tag-pill 配色，只縮小尺寸） */
.tag-pill.mini {
    padding: 0.2rem 0.55rem;
    font-size: 0.7rem;
    gap: 0.25rem;
    cursor: inherit;
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    display: inline-block;
}

/* 書庫標題列 */
.library-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 1.25rem;
}

.library-header h2 {
    margin: 0;
    flex: 1;
    min-width: 0;
}

.library-actions {
    display: flex;
    gap: 0.4rem;
    flex-shrink: 0;
}

.lib-btn {
    min-width: 40px;
    min-height: 40px;
    padding: 0 0.7rem;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--glass-border);
    color: #cbd5e1;
    border-radius: 10px;
    cursor: pointer;
    font-size: 0.82rem;
    white-space: nowrap;
    transition: background 0.15s, color 0.15s;
}

.lib-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
}

.tag {
    font-size: 0.75rem;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent-primary);
    border: 1px solid rgba(56, 189, 248, 0.2);
}

/* Modal */
.modal {
    display: none;
    /* Hidden by default */
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    align-items: center;
    justify-content: center;
}

.modal.show {
    display: flex;
    animation: fadeIn 0.3s;
}

/* Ensure review content preserves line breaks and aligns left */
.review-content {
    white-space: pre-wrap !important;
    text-align: left !important;
}

.modal-content {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 24px;
    width: 95%;
    /* Wider for mobile */
    max-width: 480px;
    max-height: 85vh;
    /* Max height relative to viewport */
    overflow-y: auto;
    /* Enable vertical scrolling */
    border: 1px solid var(--glass-border);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    position: relative;

    /* Scrollbar Styling */
    scrollbar-width: thin;
    scrollbar-color: var(--accent-secondary) transparent;
}

.modal-content::-webkit-scrollbar {
    width: 6px;
}

.modal-content::-webkit-scrollbar-track {
    background: transparent;
}

.modal-content::-webkit-scrollbar-thumb {
    background-color: var(--accent-secondary);
    border-radius: 20px;
}

.close-modal {
    position: absolute;
    top: 1.5rem;
    right: 2rem;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent-primary);
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    width: 100%;
    cursor: pointer;
    transition: transform 0.2s;
}

.btn-primary:hover {
    transform: scale(1.02);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Section specific */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.topic-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: rgba(129, 140, 248, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-secondary);
}

/* --- 閱讀偏好（文字雲）---
   HTML 排版，不是畫布。文字會自動換行，不會有字被丟掉。 */

.chart-container {
    width: 100%;
    padding: 1.5rem;
    border-radius: 16px;
    /* 用 min-height 不用 height：標籤變多時讓它自己長高，
       而不是把字擠掉或被迫內部捲動 */
    min-height: 260px;
    display: flex;
    flex-direction: column;
}

.chart-container h3 {
    margin: 0 0 0.2rem;
    align-self: flex-start;
}

.wc-label {
    align-self: flex-start;
    font-size: 0.72rem;
    font-weight: 400;
    color: #64748b;
    line-height: 1.1rem;
    margin-bottom: 0.75rem;
}

.wc-container {
    flex: 1;
    display: flex;
    align-items: center;
}

.wc-cloud {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.35rem 0.75rem;
    width: 100%;
    padding: 0.25rem 0;
}

.wc-word {
    font-family: 'Outfit', 'Noto Sans TC', 'Microsoft JhengHei', sans-serif;
    font-weight: 600;
    line-height: 1.25;
    color: #94a3b8;
    cursor: pointer;
    transition: color 0.15s, transform 0.15s;
    white-space: nowrap;
}

.wc-word:hover {
    color: #f8fafc;
    transform: translateY(-1px);
}

/* 顏色帶資訊：領域一種色，概念依使用次數分級 */
.wc-word.domain { color: #a5b4fc; }
.wc-word.hot    { color: #38bdf8; }
.wc-word.warm   { color: #7dd3fc; }

.wc-toggle {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: #94a3b8;
    border-radius: 6px;
    padding: 0.1rem 0.5rem;
    font-size: 0.7rem;
    cursor: pointer;
    margin-left: 0.35rem;
}

.wc-toggle:hover {
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.25);
}

.wc-empty {
    width: 100%;
    text-align: center;
    color: #64748b;
    font-size: 0.9rem;
}

/* --- 設定頁的金鑰疑難排解 --- */

.key-help {
    margin-top: 0.75rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
}

.key-help summary {
    cursor: pointer;
    padding: 0.75rem 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    list-style: none;
}

.key-help summary::-webkit-details-marker {
    display: none;
}

.key-help summary:hover {
    color: var(--text-primary);
}

.key-help-body {
    padding: 0 1rem 1rem;
    font-size: 0.82rem;
    line-height: 1.7;
    color: #cbd5e1;
}

.key-help-body ul,
.key-help-body ol {
    margin: 0.4rem 0 0;
    padding-left: 1.3rem;
}

.key-help-body li {
    margin-bottom: 0.35rem;
}

.key-help-body code {
    background: rgba(0, 0, 0, 0.35);
    padding: 0.1rem 0.4rem;
    border-radius: 5px;
    font-size: 0.78rem;
    color: #f8fafc;
}

.key-help-body a {
    color: var(--accent-primary);
    word-break: break-all;
}

.key-help-body .warn {
    margin-top: 1rem;
    padding: 0.7rem 0.9rem;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    border-radius: 10px;
    color: #fca5a5;
}

/* --- 主題頁改版：標籤改成密集的 pill，不再一個標籤一張大卡 --- */

.topics-toolbar {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1.25rem;
}

.topics-count {
    flex: 1;
    min-width: 160px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.topic-section {
    margin-bottom: 1.75rem;
}

.topic-section-title {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.topic-section-title .hint {
    font-size: 0.75rem;
    letter-spacing: 0;
    text-transform: none;
    color: #475569;
}

.tag-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0.45rem 0.85rem;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--glass-border);
    color: #cbd5e1;
    font-size: 0.88rem;
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
    user-select: none;
}

.tag-pill:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.25);
    color: var(--text-primary);
}

.tag-pill .n {
    font-size: 0.72rem;
    color: #64748b;
    background: rgba(0, 0, 0, 0.25);
    padding: 0.05rem 0.4rem;
    border-radius: 10px;
    min-width: 1.1rem;
    text-align: center;
}

/* 用過越多次的標籤顏色越亮，方便一眼看出哪些被用爛了 */
.tag-pill.heat-2 { border-color: rgba(56, 189, 248, 0.3); color: #bae6fd; }
.tag-pill.heat-3 { border-color: rgba(56, 189, 248, 0.55); color: #7dd3fc; background: rgba(56, 189, 248, 0.08); }

.tag-pill.domain {
    border-color: rgba(129, 140, 248, 0.35);
    color: #c7d2fe;
    background: rgba(129, 140, 248, 0.08);
}

.tag-pill.active {
    background: var(--accent-gradient);
    border-color: transparent;
    color: #0f172a;
    font-weight: 600;
}

.tag-pill.active .n {
    background: rgba(0, 0, 0, 0.2);
    color: #0f172a;
}

/* 點選標籤後展開的面板 */
.tag-panel {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1.25rem;
    margin-bottom: 1.5rem;
    animation: fadeIn 0.2s;
}

.tag-panel-head {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.tag-panel-head h3 {
    margin: 0;
    flex: 1;
    min-width: 120px;
    font-size: 1.15rem;
}

.tag-panel-actions {
    display: flex;
    gap: 0.4rem;
}

.tag-panel-actions button {
    padding: 0.6rem 0.9rem;
    background: transparent;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.8rem;
    white-space: nowrap;
    min-height: 40px;
}

.tag-panel-books {
    display: flex;
    flex-direction: column;
    max-height: 40vh;
    overflow-y: auto;
}

.tag-panel-books div {
    padding: 0.6rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    cursor: pointer;
    font-size: 0.92rem;
}

.tag-panel-books div:last-child {
    border-bottom: none;
}

.tag-panel-books div:hover {
    color: var(--accent-primary);
}

.topic-more {
    margin-top: 0.75rem;
}

.topic-more summary {
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 0.85rem;
    list-style: none;
    padding: 0.4rem 0;
}

.topic-more summary::-webkit-details-marker {
    display: none;
}

.topic-more summary:hover {
    color: var(--text-primary);
}

.topic-more[open] summary {
    margin-bottom: 0.6rem;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: rgba(15, 23, 42, 0.95);
    color: var(--text-primary);
    padding: 1rem 2rem;
    border-radius: 50px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--glass-border);
    z-index: 2000;
    /* Higher than modal */
    font-weight: 500;
    opacity: 0;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

@media (max-width: 768px) {
    .toast {
        bottom: 90px;
        width: 90%;
        justify-content: center;
    }

    /* 手機上把桌機的大留白收回來。
       原本 .main-content 24px + .view-container 48px = 左右共吃掉 144px，
       375px 的螢幕只剩 230px 能放內容，文字雲跟卡片都被擠扁。 */
    .main-content {
        padding: 1rem;
        padding-bottom: 120px;
    }

    .view-container {
        padding: 0 1rem 1.5rem 1rem;
    }

    .top-bar {
        padding: 1rem;
    }

    .book-card {
        padding: 1rem;
    }
}