/* 清新浅色主题 - 主色：青绿 Teal */
:root {
    --accent: #0d9488;
    --accent-hover: #0f766e;
    --accent-light: #ccfbf1;
    --sidebar-bg: #f8fafc;
    --card-bg: #fff;
    --border: #e2e8f0;
    --text: #334155;
    --text-muted: #64748b;
    --preview-bg: #e2e8f0;
    /* 白色设备预览背景：可选方案，取消注释其一即可 */
    /* A. 深青绿渐变（原样） */
    /* --preview-bg-white: linear-gradient(165deg, #5ea89b 0%, #6db6a9 50%, #7cc4b7 100%); */
    /* --preview-bg-white-text: #e6f7f3; */
    /* B. 暖灰（像桌面/纸面） */
    /* --preview-bg-white: linear-gradient(180deg, #6b7280 0%, #9ca3af 100%); */
    /* --preview-bg-white-text: #f3f4f6; */
    /* C. 深蓝灰 */
    /* --preview-bg-white: linear-gradient(165deg, #475569 0%, #64748b 50%, #94a3b8 100%); */
    /* --preview-bg-white-text: #e2e8f0; */
    /* D. 墨绿深色 */
    /* --preview-bg-white: linear-gradient(165deg, #134e4a 0%, #0f766e 50%, #14b8a6 100%); */
    /* --preview-bg-white-text: #ccfbf1; */
    /* E. 中性深灰 */
    --preview-bg-white: linear-gradient(180deg, #374151 0%, #4b5563 100%);
    --preview-bg-white-text: #f9fafb;
    --body-bg: #f1f5f9;
    --float-nav-bg: rgba(255, 255, 255, 0.88);
    --float-nav-border: rgba(0, 0, 0, 0.08);
    --float-nav-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
    --float-nav-hover-bg: rgba(255, 255, 255, 0.97);
    --float-nav-hover-border: rgba(0, 0, 0, 0.15);
    --canvas-bg: #fff;
    --init-loading-bg: #f0fdf4;
    --modal-card-bg: #fff;
    --bg-subtle: #f1f5f9;
    --table-row-even-bg: rgba(0, 0, 0, 0.02);
    --header-height: 52px;
    --toolbar-height: 44px;
    --touch-target-min: 44px;
    --transition-fast: 0.2s ease;
}

/* 夜间主题 */
[data-theme="dark"] {
    --accent: #14b8a6;
    --accent-hover: #0d9488;
    --accent-light: #042f2e;
    --sidebar-bg: #1e293b;
    --card-bg: #1e293b;
    --border: #334155;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --preview-bg: #0f172a;
    --preview-bg-white: linear-gradient(180deg, #374151 0%, #4b5563 100%);
    --preview-bg-white-text: #f9fafb;
    --body-bg: #0f172a;
    --float-nav-bg: rgba(30, 41, 59, 0.92);
    --float-nav-border: rgba(255, 255, 255, 0.1);
    --float-nav-shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
    --float-nav-hover-bg: rgba(51, 65, 85, 0.95);
    --float-nav-hover-border: rgba(255, 255, 255, 0.15);
    --canvas-bg: #1e293b;
    --init-loading-bg: #0f172a;
    --modal-card-bg: #1e293b;
    --bg-subtle: #334155;
    --table-row-even-bg: rgba(255, 255, 255, 0.04);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
    -webkit-user-select: none;
    user-select: none;
}

input, select, textarea {
    -webkit-user-select: text;
    user-select: text;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--body-bg);
    color: var(--text);
    overflow: hidden;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
    touch-action: manipulation;
}

/* 触摸反馈 */
button, .drop-zone, .file-item, .chapter-item {
    -webkit-tap-highlight-color: rgba(13, 148, 136, 0.1);
    transition: all var(--transition-fast);
}

button:active, .drop-zone:active, .file-item:active, .chapter-item:active {
    transform: scale(0.98);
    opacity: 0.9;
}

/* ==================== 布局 ==================== */
.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
    position: relative;
    padding-left: env(safe-area-inset-left, 0);
    padding-right: env(safe-area-inset-right, 0);
    padding-bottom: env(safe-area-inset-bottom, 0);
}

.app-bar {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
}

.app-title-wrap {
    flex: 1;
    min-width: 0;
    padding-right: 8px;
}

.app-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--accent);
    letter-spacing: -0.02em;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    display: block;
}

.app-subtitle {
    font-size: 11px;
    font-weight: 500;
    color: var(--text-muted);
    letter-spacing: 0.02em;
    margin: 2px 0 0;
    display: block;
}

.app-subtitle-short {
    display: none;
}

.app-title-short {
    display: none;
    font-size: 18px;
    font-weight: 600;
    color: var(--accent);
    letter-spacing: -0.02em;
}

.lang-switcher {
    display: flex;
    gap: 6px;
}

/* 模式切换器 */
.header-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.mode-switcher {
    display: flex;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
}

.mode-btn {
    padding: 4px 10px;
    font-size: 12px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
}

.mode-btn:hover {
    color: var(--accent);
}

.mode-btn.active {
    background: var(--accent);
    color: #fff;
}
.lang-btn {
    padding: 6px 12px;
    font-size: 13px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--card-bg);
    color: var(--text-muted);
    cursor: pointer;
    transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.lang-btn:hover {
    background: var(--accent-light);
    color: var(--accent);
    border-color: var(--accent);
}
.lang-btn.active {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.lang-toggle {
    padding: 4px 8px;
    font-size: 11px;
    border: 1px solid var(--border);
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
}
.lang-toggle:hover {
    background: var(--accent-light);
    color: var(--accent);
    border-color: var(--accent);
}

.tech-info-btn {
    padding: 4px 8px;
    font-size: 11px;
    border: 1px solid var(--border);
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
}

.tech-info-btn:hover {
    background: var(--accent-light);
    color: var(--accent);
    border-color: var(--accent);
}

/* 主题切换按钮 */
.theme-toggle {
    padding: 4px 8px;
    font-size: 18px;
    line-height: 1;
    border: 1px solid var(--border);
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
}
.theme-toggle:hover {
    background: var(--accent-light);
    color: var(--accent);
    border-color: var(--accent);
}
.theme-toggle .theme-icon {
    display: none;
}
[data-theme="light"] .theme-toggle .theme-icon-light,
[data-theme="dark"] .theme-toggle .theme-icon-dark {
    display: inline;
}
html:not([data-theme]) .theme-toggle .theme-icon-light {
    display: inline;
}
html:not([data-theme]) .theme-toggle .theme-icon-dark {
    display: none;
}

.tech-info-btn--secondary {
    display: block;
    width: 100%;
    margin-top: 10px;
    padding: 6px 0;
    font-size: 11px;
    border: none;
    background: transparent;
    color: var(--text-muted);
}

.tech-info-btn--secondary:hover {
    background: transparent;
    color: var(--accent);
}

.tech-info-btn--footer {
    display: block;
    width: 100%;
    margin-top: 6px;
    padding: 4px 0;
    font-size: 11px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    pointer-events: auto;
    cursor: pointer;
}

.tech-info-btn--footer:hover {
    background: transparent;
    color: var(--accent);
}

/* 配置区底部：仅处理说明 + 技术说明 */
.block-config-footer {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
}

.compliance-text--sidebar {
    margin: 0 0 8px 0;
    font-size: 11px;
    line-height: 1.45;
    color: var(--text-muted);
}

.preset-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 10px 8px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.preset-btn:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

.preset-btn.active {
    border-color: var(--accent);
    background: var(--accent);
    color: #fff;
}

.preset-icon {
    font-size: 18px;
    font-weight: 600;
}

.preset-name {
    font-size: 11px;
    color: var(--text-muted);
}

.preset-btn.active .preset-name {
    color: rgba(255, 255, 255, 0.9);
}

.block-config {
    margin-bottom: 16px;
}

.config-block-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin: 0 0 10px 0;
}

.config-buttons {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.quality-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.quality-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 14px 10px;
    min-height: 72px;
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 12px;
    cursor: pointer;
    transition: border-color 0.2s ease, background 0.2s ease, color 0.2s ease;
    font-family: inherit;
    text-align: center;
}

.quality-btn:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

.quality-btn.active {
    border-color: var(--accent);
    background: var(--accent);
    color: #fff;
}

.quality-btn-desc {
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
    line-height: 1.25;
}

.quality-btn.active .quality-btn-desc {
    color: #fff;
}

.quality-btn-hint {
    font-size: 10px;
    line-height: 1.35;
    color: var(--text-muted);
    text-align: center;
    max-width: 100%;
    padding: 0 4px;
}

.quality-btn.active .quality-btn-hint {
    color: rgba(255, 255, 255, 0.88);
}

.quality-mode-hidden {
    position: absolute;
    width: 0;
    height: 0;
    opacity: 0;
    pointer-events: none;
    overflow: hidden;
}

/* 专家模式隐藏 */
.expert-only {
    display: none;
}

body.expert-mode .expert-only {
    display: block;
}

body.simple-mode .expert-only {
    display: none;
}

.app-body {
    flex: 1;
    display: flex;
    min-height: 0;
}

.panel {
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}

.panel-left {
    width: 280px;
    min-width: 260px;
    max-width: 340px;
    flex-shrink: 0;
    flex-grow: 0;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    padding: 12px 14px;
}

.block {
    margin-bottom: 14px;
}

/* 区块标题（设备、方向、画面、文字、背景图） */
.block-section-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin: 0 0 10px 0;
}

/* 设备：两个大按钮 */
.block-device {
    margin-bottom: 16px;
}

.device-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.device-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 14px 10px;
    min-height: 64px;
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 12px;
    cursor: pointer;
    transition: border-color 0.22s ease, background 0.22s ease, color 0.22s ease, box-shadow 0.22s ease;
    font-family: inherit;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    text-align: center;
}

.device-btn:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

.device-btn.active {
    border-color: var(--accent);
    background: var(--accent);
    color: #fff;
    box-shadow: 0 4px 14px rgba(13, 148, 136, 0.35);
}

.device-btn-name {
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
    line-height: 1.25;
}

.device-btn.active .device-btn-name {
    color: #fff;
}

.device-btn-res {
    font-size: 10px;
    color: var(--text-muted);
}

.device-btn.active .device-btn-res {
    color: rgba(255, 255, 255, 0.88);
}

/* 方向：四个图标按钮（主面板内） */
.block-orientation {
    margin-bottom: 16px;
}

.orientation-buttons-block {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
}

.orientation-buttons-block .orientation-btn {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    font-family: inherit;
}

.orientation-buttons-block .orientation-btn:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

.orientation-buttons-block .orientation-btn.active {
    border-color: var(--accent);
    background: var(--accent);
    color: #fff;
}

.orientation-icon-svg {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    background-repeat: no-repeat;
    background-position: center;
    background-size: 20px 28px;
    background-image: url(imgs/xt-device-black.svg);
}

.orientation-buttons-block .orientation-btn.active .orientation-icon-svg {
    background-image: url(imgs/xt-device-white.svg);
}

/* 四个方向：同一设备图标旋转 0°/90°/180°/270° */
.orientation-buttons-block .orientation-btn[data-orientation="0"] .orientation-icon-svg {
    transform: rotate(0deg);
}
.orientation-buttons-block .orientation-btn[data-orientation="90"] .orientation-icon-svg {
    transform: rotate(90deg);
}
.orientation-buttons-block .orientation-btn[data-orientation="180"] .orientation-icon-svg {
    transform: rotate(180deg);
}
.orientation-buttons-block .orientation-btn[data-orientation="270"] .orientation-icon-svg {
    transform: rotate(270deg);
}

/* 画面：第二行 漫画感/均衡/照片感 */
.block-screen .screen-preset-row {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
    margin-top: 10px;
}

.block-screen .screen-preset-row .preset-btn {
    padding: 10px 8px;
}

.block-screen .screen-preset-row .preset-btn .preset-name {
    font-size: 12px;
}

/* 文字：字号预设行 */
.text-size-preset-row {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
    margin-top: 10px;
}

.text-size-preset-row .preset-btn {
    padding: 10px 8px;
}

.text-size-preset-row .preset-btn .preset-name {
    font-size: 12px;
}

.block-font .control-group-font-select {
    margin-bottom: 0;
}

.block-font .control-group-font-select select {
    width: 100%;
    padding: 10px 32px 10px 12px;
    border-radius: 8px;
    border: 1px solid var(--border);
    font-size: 13px;
}

/* 背景图：两行按钮 */
.bg-image-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.bg-image-row {
    display: grid;
    gap: 8px;
}

.bg-image-row:first-child {
    grid-template-columns: 1fr 1fr;
}

.bg-image-option-btn,
.bg-image-upload-btn {
    padding: 12px 14px;
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    font-family: inherit;
    text-align: center;
}

.bg-image-option-btn:hover,
.bg-image-upload-btn:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

.bg-image-upload-btn {
    width: 100%;
}

/* 背景图：拉伸/平铺 与 清除 一行 */
.bg-image-mode-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.bg-image-mode-row select#bgImageMode {
    min-width: 120px;
    padding: 10px 32px 10px 12px;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text);
    font-size: 13px;
    font-family: inherit;
    cursor: pointer;
}

.bg-image-mode-row select#bgImageMode:hover,
.bg-image-mode-row select#bgImageMode:focus {
    border-color: var(--accent);
    outline: none;
}

.bg-image-clear-btn {
    padding: 10px 14px;
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    font-family: inherit;
}

.bg-image-clear-btn:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

/* 文字下划线区块 */
.block-underline {
    margin-bottom: 16px;
}

.underline-checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 13px;
    color: var(--text);
}

.underline-checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.underline-hint {
    margin-top: 4px;
    margin-left: 26px;
    font-size: 12px;
    color: var(--text-muted);
}

.block-files .file-list {
    margin-bottom: 0;
}

.block-book {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 10px 12px;
    border-left: 3px solid var(--accent);
}

.book-title {
    font-weight: 600;
    font-size: 14px;
    word-break: break-word;
    color: var(--text);
}

.book-author {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 2px;
}

/* 可折叠区块 */
.section {
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 10px;
    background: var(--card-bg);
}

.section-head {
    padding: 8px 12px;
    font-size: 12px;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.03em;
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 6px;
}

.section-head::-webkit-details-marker {
    display: none;
}

.section-head::before {
    content: '';
    display: inline-block;
    width: 0;
    height: 0;
    border-left: 5px solid var(--accent);
    border-top: 4px solid transparent;
    border-bottom: 4px solid transparent;
    transition: transform 0.2s;
}

.section[open] .section-head::before {
    transform: rotate(90deg);
}

.section-body {
    padding: 0 12px 12px;
    border-top: 1px solid var(--border);
    overflow: hidden;
}

.section-body .control-group:first-child,
.section-body .checkbox-group:first-child,
.section-body .progress-bar-row:first-child {
    margin-top: 10px;
}

.section-head.plain {
    cursor: default;
}

.section-head.plain::before {
    display: none;
}

.subsection {
    margin-top: 8px;
    margin-left: 4px;
    border-left: 2px solid var(--border);
    padding-left: 10px;
}

.subsection-head {
    font-size: 12px;
    color: var(--text-muted);
    cursor: pointer;
    list-style: none;
}

.subsection-head::-webkit-details-marker { display: none; }
.subsection-head::before { content: '▸ '; display: inline-block; transition: transform 0.2s; }
.subsection[open] .subsection-head::before { content: '▾ '; }

.subsection-body {
    padding: 6px 0 8px;
}

.subsection-body .control-group { margin-top: 8px; }
.subsection-body .checkbox-group { margin-top: 6px; }

.underline-options-group {
    margin-top: 10px;
    padding-left: 12px;
    border-left: 2px solid var(--border);
}
.underline-options-group .control-group { margin-bottom: 10px; }
.underline-options-group .control-group:last-child { margin-bottom: 0; }
.underline-effect-row {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 0;
}
.underline-effect-row select { flex: 0 0 auto; min-width: 100px; }

.hint {
    font-size: 11px;
    color: var(--text-muted);
    margin: 4px 0 8px;
}

.font-mode-hint {
    font-size: 11px;
    color: var(--text-muted);
    margin: 6px 0;
    line-height: 1.35;
}

.font-mode-hint-sep {
    border: none;
    border-top: 1px solid var(--border);
    margin: 0 0 6px 0;
}

.custom-font-file-wrap {
    margin-top: 8px;
}

.drop-zone {
    border: 2px dashed var(--border);
    border-radius: 8px;
    padding: 16px 12px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 10px;
    background: var(--card-bg);
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--accent);
    background: var(--accent-light);
}

.drop-zone-icon {
    font-size: 32px;
    margin-bottom: 8px;
    color: var(--accent);
}

.drop-zone-text {
    font-size: 13px;
    color: var(--text-muted);
}

.drop-zone-formats {
    font-size: 11px;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin: 10px 0 6px;
}

.format-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px;
    margin-top: 4px;
}

.format-badge {
    font-size: 11px;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 999px;
    letter-spacing: 0.03em;
}

.format-badge-epub {
    background: rgba(13, 148, 136, 0.15);
    color: var(--accent);
}

.format-badge-pdf {
    background: rgba(239, 68, 68, 0.12);
    color: #dc2626;
}

.format-badge-mobi {
    background: rgba(99, 102, 241, 0.15);
    color: #4f46e5;
}

.format-badge-txt {
    background: rgba(34, 197, 94, 0.15);
    color: #16a34a;
}

.format-badge-md {
    background: rgba(168, 85, 247, 0.15);
    color: #7c3aed;
}

.format-badge-doc {
    background: rgba(2, 132, 199, 0.15);
    color: #0369a1;
}

.format-badge-pptx {
    background: rgba(234, 88, 12, 0.15);
    color: #c2410c;
}

.file-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px;
    background: var(--card-bg);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.file-details {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.file-name {
    font-size: 13px;
    color: var(--text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.book-author {
    font-size: 12px;
    color: var(--text-muted);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    margin-top: 2px;
}

.btn-small {
    padding: 6px 12px;
    font-size: 12px;
    border-radius: 4px;
    flex-shrink: 0;
}

/* 专家模式：批量转换开关与文件列表 */
.batch-mode-wrap {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid var(--border, #e5e7eb);
}
.batch-toggle-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-muted, #6b7280);
    cursor: pointer;
}
.batch-toggle-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
}
.file-list-wrap {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid var(--border, #e5e7eb);
}
.file-list-count {
    font-size: 12px;
    color: var(--text-muted, #6b7280);
    margin-bottom: 8px;
}
.file-list-items {
    max-height: 140px;
    overflow-y: auto;
    margin-bottom: 10px;
}
.file-list-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 10px;
    background: var(--card-bg, #f9fafb);
    border-radius: 6px;
    margin-bottom: 4px;
    font-size: 12px;
    border: 1px solid var(--border, #e5e7eb);
    cursor: pointer;
}
.file-list-item:hover {
    background: var(--hover-bg, #f3f4f6);
}
.file-list-item.active {
    background: var(--accent, #0d9488);
    color: #fff;
    border-color: var(--accent, #0d9488);
}
.file-list-item-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.file-list-item-remove {
    flex-shrink: 0;
    padding: 0 4px;
    cursor: pointer;
    opacity: 0.7;
    font-size: 16px;
    line-height: 1;
}
.file-list-item-remove:hover {
    opacity: 1;
}
.file-list-item.active .file-list-item-remove {
    opacity: 0.9;
}
.btn-export-all {
    width: 100%;
    margin-top: 6px;
}

.file-list {
    max-height: 120px;
    overflow-y: auto;
    margin-bottom: 10px;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    background: var(--card-bg);
    border-radius: 6px;
    margin-bottom: 4px;
    font-size: 12px;
    border: 1px solid var(--border);
}

.file-item.active {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.file-item .name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    cursor: pointer;
}

.file-item .remove {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
    margin-left: 8px;
}

.file-item .remove:hover {
    color: var(--accent);
}

/* Control Groups */
.control-group {
    margin-bottom: 12px;
}

.section-body {
    padding: 0 12px 12px;
    border-top: 1px solid var(--border);
}

.control-group label {
    display: block;
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.control-group select,
.control-group input[type="text"],
.control-group input[type="number"] {
    width: 100%;
    padding: 8px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text);
    font-size: 13px;
}

.control-group select:focus,
.control-group input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-light);
}

/* Slider Row */
.slider-row {
    display: flex;
    gap: 8px;
    align-items: center;
}

.slider-row input[type="range"] {
    flex: 1;
}

.slider-row input[type="number"] {
    width: 60px;
}

.margins-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.margin-cell {
    display: flex;
    align-items: center;
    gap: 6px;
}

.margin-cell span {
    font-size: 11px;
    color: var(--text-muted);
    min-width: 36px;
}

.margin-cell input {
    flex: 1;
    min-width: 0;
}

input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    background: var(--border);
    border-radius: 4px;
    height: 6px;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
}

/* Checkbox */
.checkbox-group {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.checkbox-group input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--accent);
}

.checkbox-group label {
    font-size: 13px;
    color: var(--text);
    margin: 0;
}

/* Checkbox row for multiple checkboxes */
.checkbox-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 16px;
    margin-bottom: 8px;
}

.checkbox-row .checkbox-group {
    margin-bottom: 0;
}

/* Progress bar settings row */
.progress-bar-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.progress-bar-row .checkbox-group {
    margin-bottom: 0;
}

.progress-bar-row select {
    padding: 6px 8px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text);
    font-size: 12px;
}

/* Chapter List */
.chapter-list {
    max-height: 200px;
    overflow-y: auto;
    background: var(--card-bg);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.chapter-item {
    padding: 8px 12px;
    font-size: 12px;
    cursor: pointer;
    border-bottom: 1px solid var(--border);
    color: var(--text-muted);
}

.chapter-item:hover {
    background: var(--accent-light);
    color: var(--accent);
}

.chapter-item.active {
    background: var(--accent);
    color: #fff;
}

.chapter-item:last-child {
    border-bottom: none;
}

/* 右侧预览区 */
.panel-right {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--preview-bg);
    min-width: 0;
    overflow: hidden;
}

.preview-toolbar {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 6px 12px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
}

.toolbar-group {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.btn {
    padding: 6px 12px;
    font-size: 13px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--card-bg);
    color: var(--text);
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.btn:hover {
    background: var(--accent-light);
    border-color: var(--accent);
    color: var(--accent);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    font-weight: 600;
}

.btn-primary:hover:not(:disabled) {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
}

.preview-toolbar .page-info {
    font-size: 13px;
    color: var(--text-muted);
    flex-shrink: 0;
}

.preview-toolbar .btn-icon-label {
    min-width: 44px;
    padding: 6px 10px;
    font-size: 12px;
}

/* Preview Area */
.preview-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
    overflow: hidden;
    background: var(--preview-bg);
    position: relative;
}

/* 白色设备预览时使用深色背景，突出白机 */
.preview-area:has(.device-frame[data-skin="white"]) {
    background: var(--preview-bg-white);
}
.preview-area:has(.device-frame[data-skin="white"]) .preview-empty {
    background: var(--preview-bg-white);
}
.preview-area:has(.device-frame[data-skin="white"]) .empty-title,
.preview-area:has(.device-frame[data-skin="white"]) .empty-desc {
    color: var(--preview-bg-white-text);
}

/* 预览区右上角：黑白设备边框开关 */
.device-skin-switch {
    position: absolute;
    top: 12px;
    right: 12px;
    z-index: 10;
    display: flex;
    align-items: center;
    gap: 0;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    overflow: hidden;
}
.device-skin-btn {
    padding: 6px 14px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-muted);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}
.device-skin-btn:hover {
    color: var(--text);
    background: var(--accent-light);
}
.device-skin-btn.active {
    color: #fff;
    background: var(--accent);
}
.device-skin-btn[data-skin="black"].active {
    color: #fff;
    background: #374151;
}
.device-skin-btn[data-skin="white"].active {
    color: #1f2937;
    background: #e5e7eb;
}

/* 预览旋转包装：整体缩放（最大 80% 预览区）+ 旋转，简洁自适应 */
.preview-canvas-wrap {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
    transform-origin: center center;
    --preview-wrap-scale: 1;
}
.preview-canvas-wrap[data-rotate="0"]   { transform: scale(var(--preview-wrap-scale)) rotate(0deg); }
.preview-canvas-wrap[data-rotate="90"]  { transform: scale(var(--preview-wrap-scale)) rotate(90deg); }
.preview-canvas-wrap[data-rotate="180"] { transform: scale(var(--preview-wrap-scale)) rotate(-180deg); }
.preview-canvas-wrap[data-rotate="270"] { transform: scale(var(--preview-wrap-scale)) rotate(-90deg); }

/* 设备边框（类似 Kindle）：左右等宽、下巴大，贴近真机；屏显略缩小让边框更明显 */
.device-frame {
    position: relative;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px 26px 88px;
    background: linear-gradient(145deg, #2d2d2d 0%, #1a1a1a 100%);
    border-radius: 16px;
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.06),
        0 8px 24px rgba(0, 0, 0, 0.25),
        0 2px 6px rgba(0, 0, 0, 0.15);
}
.device-chin-btns {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 8px;
    width: 80%;
    justify-content: center;
}
.device-chin-btn {
    flex: 1;
    max-width: 48%;
    height: 10px;
    background: rgba(255, 255, 255, 0.22);
    border-radius: 999px;
}
.device-frame[data-skin="white"] .device-chin-btn {
    background: rgba(0, 0, 0, 0.18);
}

/* 白色机器 */
.device-frame[data-skin="white"] {
    background: linear-gradient(145deg, #f5f5f5 0%, #e8e8e8 100%);
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.8),
        0 8px 24px rgba(0, 0, 0, 0.12),
        0 2px 6px rgba(0, 0, 0, 0.08);
}

/* 右侧按键：电源键（靠上）+ 音量键（居中，两条竖条），凸出在边框外侧、贴边无空隙 — X4 样式 */
.device-frame-keys-right {
    position: absolute;
    top: 0;
    right: -4px;
    bottom: 0;
    width: 8px;
    box-sizing: border-box;
}
/* 按键通用外观；定位仅用于右侧键，避免左侧键被 right:0 影响 */
.device-key {
    display: block;
    width: 4px;
    border-radius: 2px;
    background: rgba(0, 0, 0, 0.6);
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.3);
}
.device-frame-keys-right .device-key {
    position: absolute;
    right: 0;
}
.device-frame[data-skin="white"] .device-key {
    background: linear-gradient(90deg, #e8e8e8 0%, #ddd 100%);
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}
.device-key-power {
    top: 88px;
    height: 80px;
}
.device-key-vol {
    top: 50%;
    width: 4px;
    height: 88px;
    transform: translateY(-50%);
    box-shadow: none;
}
.device-key-vol-1 {
    margin-top: -44px;
}
.device-key-vol-2 {
    margin-top: 44px;
}
.device-frame[data-skin="white"] .device-key-vol {
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

/* X4 右侧下键（X3 专用元素）默认隐藏 */
.device-key-down-right {
    display: none;
}
/* X3 顶部电源（默认隐藏） */
.device-frame-keys-top {
    display: none;
}
.device-frame[data-device="xteink-x4"] .device-frame-keys-left,
.device-frame:not([data-device="xteink-x3"]) .device-frame-keys-left {
    display: none !important;
}
.device-frame[data-device="xteink-x4"] .device-key-down-right,
.device-frame:not([data-device="xteink-x3"]) .device-key-down-right {
    display: none !important;
}
.device-frame[data-device="xteink-x4"] .device-frame-keys-top,
.device-frame:not([data-device="xteink-x3"]) .device-frame-keys-top {
    display: none !important;
}

/* X3：电源在顶部（非右侧）；左侧上/下键、右侧下键 加长并上移 */
.device-frame[data-device="xteink-x3"] .device-frame-keys-right .device-key-power {
    display: none;
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-right .device-key-vol-1,
.device-frame[data-device="xteink-x3"] .device-frame-keys-right .device-key-vol-2 {
    display: none;
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-right .device-key-down-right {
    display: block;
    top: 50%;
    margin-top: -290px;
    height: 100px;
    transform: none;
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-top {
    display: block;
    position: absolute;
    top: -4px;
    left: 0;
    right: 0;
    height: 8px;
    padding: 0 60px 0 0;
    box-sizing: border-box;
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-top .device-key-power-top {
    position: absolute;
    top: 0;
    right: 52px;
    width: 56px;
    height: 4px;
    border-radius: 2px;
    background: rgba(0, 0, 0, 0.6);
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.3);
}
.device-frame[data-device="xteink-x3"][data-skin="white"] .device-frame-keys-top .device-key-power-top {
    background: linear-gradient(180deg, #e8e8e8 0%, #ddd 100%);
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-left {
    position: absolute;
    top: 50%;
    left: -4px;
    width: 20px;
    height: 100px;
    margin-top: -290px;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    gap: 6px;
    box-sizing: border-box;
}
/* X3 左侧键：独立 class，不共用 .device-key，避免被全局/右侧样式影响导致飘出 */
.device-frame[data-device="xteink-x3"] .device-frame-keys-left .device-key-x3-left-up,
.device-frame[data-device="xteink-x3"] .device-frame-keys-left .device-key-x3-left-down {
    flex-shrink: 0;
    width: 4px;
    height: 100px;
    border-radius: 2px;
    background: rgba(0, 0, 0, 0.6);
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.3);
}
.device-frame[data-device="xteink-x3"][data-skin="white"] .device-frame-keys-left .device-key-x3-left-up,
.device-frame[data-device="xteink-x3"][data-skin="white"] .device-frame-keys-left .device-key-x3-left-down {
    background: linear-gradient(90deg, #e8e8e8 0%, #ddd 100%);
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-left .device-key-x3-left-up {
    order: 0;
}
.device-frame[data-device="xteink-x3"] .device-frame-keys-left .device-key-x3-left-down {
    order: 1;
    display: none;
}

#previewCanvas {
    background: var(--canvas-bg);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.029);
    transform: scale(var(--preview-scale, 1)) scale(var(--preview-inner-scale, 0.95));
    transform-origin: center center;
    border-radius: 8px;
    overflow: hidden;
}

/* 空状态 */
.preview-empty {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 32px 24px;
    background: var(--preview-bg);
    z-index: 5;
    cursor: pointer;
}

.preview-empty.hidden {
    display: none;
}

.empty-book-icon {
    opacity: 0.9;
    flex-shrink: 0;
}

.empty-title {
    font-size: 17px;
    font-weight: 600;
    color: var(--text);
    margin: 0;
}

.empty-desc {
    font-size: 13px;
    color: var(--text-muted);
    margin: 0;
    text-align: center;
    max-width: 240px;
    line-height: 1.6;
}

/* 浮动翻页按钮 */
.float-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    width: 36px;
    height: 80px;
    background: var(--float-nav-bg);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--float-nav-border);
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.2s, background 0.2s, color 0.2s, box-shadow 0.2s;
    box-shadow: var(--float-nav-shadow);
    color: var(--text);
}

.float-nav:hover:not(:disabled) {
    background: var(--float-nav-hover-bg);
    color: var(--accent);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    border-color: rgba(13, 148, 136, 0.3);
}

.float-nav:active:not(:disabled) {
    transform: translateY(-50%) scale(0.95);
}

.float-nav:disabled {
    opacity: 0;
    pointer-events: none;
}

.float-prev {
    left: 10px;
}

.float-next {
    right: 10px;
}

/* Progress Bar（页面内嵌用，如需要） */
.progress-container {
    flex-shrink: 0;
    padding: 8px 16px;
    padding-bottom: calc(8px + env(safe-area-inset-bottom, 0));
    background: var(--card-bg);
    border-top: 1px solid var(--border);
}

/* 导出进度：独立全屏遮罩，遮盖背后并禁止操作 */
.export-progress-overlay.progress-container {
    position: fixed;
    inset: 0;
    z-index: 9999;
    flex-shrink: unset;
    padding: 0;
    border: none;
    border-top: none;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
}
.export-progress-overlay .export-progress-card {
    background: var(--card-bg);
    padding: 24px 32px;
    border-radius: 12px;
    min-width: 280px;
    width: 90%;
    max-width: 360px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}
.export-progress-overlay .progress-bar {
    width: 100%;
}

.progress-bar {
    position: relative;
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--accent);
    width: 0%;
    transition: width 0.3s;
}

@keyframes progress-indeterminate {
    0%   { left: -40%; width: 40%; }
    60%  { left: 100%; width: 40%; }
    100% { left: 100%; width: 40%; }
}
.progress-fill--indeterminate {
    position: relative;
    width: 40% !important;
    transition: none;
    animation: progress-indeterminate 1.2s ease-in-out infinite;
}

.progress-text {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 4px;
    text-align: center;
}

/* Settings toggle button — mobile only */
.settings-toggle-btn {
    display: none;
    flex-shrink: 0;
    font-size: 12px;
    padding: 6px 10px;
    min-width: 52px;
}

/* Canvas zoom-in cursor when a file is loaded */
#previewCanvas.has-file {
    cursor: zoom-in;
}

/* Lightbox overlay */
.preview-lightbox {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.92);
    align-items: center;
    justify-content: center;
    cursor: zoom-out;
    padding: env(safe-area-inset-top, 0) env(safe-area-inset-right, 0) env(safe-area-inset-bottom, 0) env(safe-area-inset-left, 0);
    -webkit-tap-highlight-color: transparent;
}

.preview-lightbox.open {
    display: flex;
}

.tech-modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1200;
    background: rgba(15, 23, 42, 0.42);
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.tech-modal.open {
    display: flex;
}

.tech-modal-card {
    width: min(640px, 92vw);
    max-height: min(80vh, 760px);
    overflow: auto;
    background: var(--modal-card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: 0 16px 40px rgba(15, 23, 42, 0.2);
    padding: 14px 16px;
}

.tech-modal-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 8px;
}

.tech-modal-head h3 {
    margin: 0;
    font-size: 16px;
    color: var(--text);
}

.tech-modal-close {
    width: 30px;
    height: 30px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--card-bg);
    color: var(--text-muted);
    font-size: 18px;
    line-height: 1;
    cursor: pointer;
}

.tech-modal-close:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-light);
}

.tech-modal-desc {
    margin: 0 0 10px;
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.5;
}

/* 导出确认框：信息块 + 确认问句，层次清晰 */
.export-confirm-card .export-confirm-body {
    margin: 4px 0 0;
}

.export-confirm-info {
    background: var(--bg-subtle);
    border-radius: 10px;
    padding: 14px 16px;
    margin-bottom: 14px;
}

.export-confirm-row {
    margin: 0;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text);
}

.export-confirm-row + .export-confirm-row {
    margin-top: 8px;
}

#exportConfirmCloud,
#exportConfirmUsb {
    font-weight: 700;
}

#exportConfirmRecommend {
    margin-top: 10px;
    font-size: 14px;
    font-weight: 700;
    color: #d32f2f;
}

.export-confirm-row:first-child {
    font-weight: 600;
    color: var(--text);
}

.export-confirm-question {
    margin: 0;
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
    line-height: 1.5;
}

.export-confirm-xtcz-tip {
    display: none;
    margin: 10px 0 0;
    font-size: 13px;
    color: var(--text-muted, #64748b);
    line-height: 1.5;
}

.export-confirm-actions {
    display: flex;
    gap: 10px;
    margin-top: 16px;
    flex-wrap: wrap;
}

.tech-modal-subtitle {
    margin: 10px 0 6px;
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
}

.tech-modal-list {
    margin: 0 0 8px 18px;
    padding: 0;
    color: var(--text-muted);
}

.tech-modal-list li {
    margin-bottom: 4px;
    font-size: 13px;
    line-height: 1.45;
}

.tech-modal-card--wide {
    width: min(720px, 94vw);
}

.tech-modal-card--compact {
    width: min(320px, 92vw);
    max-height: none;
}

.page-jump-modal-body {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 4px;
}

.page-jump-modal-body .page-jump-label {
    font-size: 13px;
    color: var(--text-muted);
    margin: 0;
}

.page-jump-modal-body .page-jump-input {
    width: 4em;
    min-width: 52px;
    padding: 8px 10px;
    font-size: 14px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--card-bg);
    color: var(--text);
    text-align: center;
}

.page-jump-modal-body .page-jump-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-light);
}

.page-jump-of {
    font-size: 13px;
    color: var(--text-muted);
}

.page-jump-modal-body .btn {
    margin-left: auto;
}

.usage-guide-body {
    max-height: min(70vh, 640px);
    overflow-y: auto;
}

.usage-guide-body .usage-guide-h4 {
    margin: 14px 0 6px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
}
.usage-guide-body .usage-guide-h4:first-of-type {
    margin-top: 0;
}
.usage-guide-body .usage-guide-p {
    margin: 0 0 8px;
    font-size: 13px;
    line-height: 1.5;
    color: var(--text-muted);
}
.usage-guide-body .usage-guide-ol {
    margin: 0 0 8px 20px;
    padding: 0;
    font-size: 13px;
    line-height: 1.5;
    color: var(--text-muted);
}
.usage-guide-body .usage-guide-ol li {
    margin-bottom: 4px;
}
.usage-guide-body .usage-guide-summary {
    margin: 0 0 4px;
    font-size: 12px;
    font-weight: 500;
    color: var(--text);
    font-style: italic;
}
.usage-guide-table-intro {
    margin-bottom: 8px !important;
}
.usage-guide-table-wrap {
    overflow-x: auto;
    margin-bottom: 8px;
}
.usage-guide-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
}
.usage-guide-table th,
.usage-guide-table td {
    padding: 6px 10px;
    border: 1px solid var(--border);
    text-align: left;
    vertical-align: top;
}
.usage-guide-table th {
    background: var(--bg-subtle);
    font-weight: 600;
    color: var(--text);
}
.usage-guide-table td {
    color: var(--text-muted);
}
.usage-guide-table tbody tr:nth-child(even) {
    background: var(--table-row-even-bg);
}
.tech-modal-card--usage {
    max-height: min(85vh, 720px);
}

.lightbox-img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.6);
    pointer-events: none;
}

/* Initial loading overlay */
.init-loading-overlay {
    position: fixed;
    inset: 0;
    z-index: 10000;
    background: var(--init-loading-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.4s ease;
}
.init-loading-overlay.fade-out {
    opacity: 0;
    pointer-events: none;
}
.init-loading-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 18px;
    padding: 36px 48px;
}
.init-loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--accent-light, #ccfbf1);
    border-top-color: var(--accent, #0d9488);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.init-loading-text {
    color: var(--text, #334155);
    font-size: 15px;
    font-weight: 500;
    letter-spacing: 0.02em;
}
.init-loading-bar-track {
    width: 220px;
    height: 6px;
    background: var(--border, #e2e8f0);
    border-radius: 3px;
    overflow: hidden;
}
.init-loading-bar-fill {
    height: 100%;
    width: 0%;
    background: var(--accent, #0d9488);
    border-radius: 3px;
    transition: width 0.3s ease;
}

/* Repaginate loading overlay */
.repaginate-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: rgba(0, 0, 0, 0.35);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 14px;
    cursor: wait;
}
.repaginate-overlay.active {
    display: flex;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}
.repaginate-spinner {
    width: 36px;
    height: 36px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.repaginate-text {
    color: #fff;
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 0.02em;
}

/* 文件加载 loading 遮罩 */
.file-loading-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 9998;
    background: rgba(0, 0, 0, 0.4);
    align-items: center;
    justify-content: center;
    cursor: wait;
}
.file-loading-overlay.active {
    display: flex;
}
.file-loading-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    padding: 28px 40px;
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    min-width: 200px;
}
.file-loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--accent-light, #ccfbf1);
    border-top-color: var(--accent, #0d9488);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.file-loading-text {
    color: var(--text, #334155);
    font-size: 15px;
    font-weight: 500;
}
.file-loading-overlay.done .file-loading-spinner {
    animation: none;
    border-color: var(--accent);
}

/* Hidden file input */
#fileInput, #customFontInput {
    display: none;
}

/* Tabs - 注释掉
.tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 10px;
}
*/

/* Optimizer / Progress labels */
.optimizer-desc {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.progress-line-label {
    font-size: 11px;
    color: var(--text-muted);
    margin: 8px 0 4px;
    display: block;
}

/* Tab panel - 注释掉
.tab-panel {
    display: none;
}

.tab-panel.active {
    display: block;
}

.tabs .tab-btn {
    flex: 1;
    padding: 6px 10px;
    font-size: 12px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-muted);
    cursor: pointer;
}

.tabs .tab-btn:hover {
    background: var(--accent-light);
    color: var(--accent);
    border-color: var(--accent);
}

.tabs .tab-btn.active {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}
*/

.block .btn-primary {
    width: 100%;
    margin-top: 10px;
}

.control-readonly {
    margin-bottom: 0;
}

.control-readonly label {
    font-size: 11px;
    color: var(--text-muted);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--sidebar-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ==================== 响应式 / 移动端适配 ==================== */

/* 大屏：左侧面板更紧凑，预览区域最大化 */
@media (min-width: 1200px) {
    .panel-left {
        width: 260px;
        min-width: 240px;
        max-width: 300px;
        padding: 10px 12px;
    }
    .panel-left .section-head {
        font-size: 11px;
        padding: 6px 10px;
    }
    .panel-left .section-body {
        padding: 0 10px 10px;
    }
    .block {
        margin-bottom: 10px;
    }
    .drop-zone {
        padding: 12px 10px;
    }
    .drop-zone-icon {
        font-size: 24px;
    }
    .drop-zone-text {
        font-size: 11px;
    }
    .control-group {
        margin-bottom: 8px;
    }
    .control-group label {
        font-size: 11px;
    }
    .chapter-list {
        max-height: 150px;
    }
}

/* 平板及以下：左侧面板在上、预览在下，左侧限高可滚动 */
@media (max-width: 800px) {
    .settings-toggle-btn {
        display: block;
    }

    /* 收起状态：panel-left 高度归零 */
    .panel-left.panel-collapsed {
        max-height: 0 !important;
        min-height: 0 !important;
        padding-top: 0 !important;
        padding-bottom: 0 !important;
        border-bottom: none !important;
        overflow: hidden;
        transition: max-height 0.25s ease, padding 0.25s ease;
    }

    /* 展开状态：平滑过渡 */
    .panel-left {
        transition: max-height 0.25s ease, padding 0.25s ease;
    }
    .app-body {
        flex-direction: column;
    }
    .panel-left {
        width: 100%;
        min-width: 0;
        max-width: none;
        max-height: 45vh;
        min-height: 120px;
        flex-shrink: 0;
        padding: 8px 14px;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    .panel-left .section-head {
        font-size: 11px;
        padding: 6px 10px;
    }
    .panel-left .section-body {
        padding: 0 10px 10px;
    }
    .block-book {
        padding: 8px 10px;
        margin-bottom: 10px;
    }
    .book-title {
        font-size: 13px;
    }
    .book-author {
        font-size: 11px;
    }
    .drop-zone {
        padding: 10px 8px;
    }
    .drop-zone-icon {
        font-size: 22px;
    }
    .drop-zone-text {
        font-size: 11px;
    }
    .drop-zone-formats {
        font-size: 10px;
        margin: 8px 0 4px;
    }
    .format-badge {
        font-size: 10px;
        padding: 3px 8px;
    }
    .file-list {
        max-height: 80px;
    }
    .file-item {
        padding: 6px 10px;
        font-size: 12px;
    }
    /* tabs - 注释掉
    .tabs {
        margin-bottom: 8px;
    }
    .tabs .tab-btn {
        padding: 6px 10px;
        font-size: 12px;
    }
    */
    .panel-left .control-group {
        margin-bottom: 8px;
    }
    .panel-left .control-group label {
        font-size: 11px;
        margin-bottom: 2px;
    }
    .panel-left .control-group select,
    .panel-left .control-group input[type="text"],
    .panel-left .control-group input[type="number"] {
        padding: 8px 10px;
        font-size: 14px;
        min-height: 36px;
    }
    .slider-row input[type="number"] {
        width: 50px;
    }
    input[type="range"] {
        height: 6px;
    }
    input[type="range"]::-webkit-slider-thumb {
        width: 20px;
        height: 20px;
    }
    .panel-left .checkbox-group {
        margin-bottom: 6px;
    }
    .panel-left .checkbox-group label {
        font-size: 13px;
    }
    .panel-left .checkbox-group input[type="checkbox"] {
        width: 18px;
        height: 18px;
    }
    .orientation-buttons-block .orientation-btn {
        padding: 8px 6px;
        font-size: 12px;
        min-height: 36px;
    }
    .chapter-list {
        max-height: 100px;
    }
    .chapter-item {
        padding: 8px 10px;
        font-size: 12px;
    }
    .panel-right {
        flex: 1;
        min-height: 0;
    }
    .preview-area {
        flex: 1;
        min-height: 0;
        padding: 8px;
    }
    .device-skin-switch {
        top: 8px;
        right: 8px;
    }
    .device-skin-btn {
        padding: 5px 12px;
        font-size: 12px;
    }
    .preview-toolbar {
        min-height: var(--toolbar-height);
        padding: 6px 10px;
    }
    .preview-toolbar .btn {
        min-height: 32px;
        min-width: 44px;
    }
    .float-nav {
        width: 32px;
        height: 64px;
    }
    .float-prev { left: 6px; }
    .float-next { right: 6px; }
    .empty-title { font-size: 15px; }
    .empty-desc { font-size: 12px; }
}

/* 手机竖屏：顶栏与工具栏更紧凑，左右留白避免贴边 */
@media (max-width: 600px) {
    .screen-preset-row,
    .text-size-preset-row {
        gap: 6px;
    }
    .preset-btn {
        padding: 8px 6px;
        border-radius: 7px;
    }
    .preset-icon {
        font-size: 16px;
    }
    .preset-name {
        font-size: 10px;
    }
    .quality-buttons {
        gap: 8px;
    }
    .quality-btn {
        gap: 4px;
        padding: 10px 8px;
        min-height: 58px;
        border-radius: 10px;
    }
    .quality-btn-desc {
        font-size: 12px;
    }
    .quality-btn-hint {
        font-size: 9px;
        line-height: 1.25;
        padding: 0 2px;
    }

    .app-bar {
        padding: 8px 16px;
        min-height: var(--header-height);
    }
    .app-title-wrap .app-title,
    .app-title-wrap .app-subtitle {
        display: none;
    }
    .app-title-short {
        display: block;
        font-size: 16px;
        font-weight: 600;
    }
    .app-title {
        font-size: 16px;
        font-weight: 600;
    }
    .app-subtitle {
        font-size: 10px;
    }
    .app-subtitle-long {
        display: none;
    }
    .app-subtitle-short {
        display: block;
    }
    .panel-left {
        width: 100%;
        min-width: 0;
        max-width: none;
        max-height: 40vh;
        padding: 10px 16px;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    .panel-left .section-head {
        font-size: 11px;
        padding: 6px 12px;
    }
    .preview-toolbar {
        flex-wrap: nowrap;
        gap: 6px 8px;
        padding: 8px 16px;
        justify-content: space-between;
    }
    .preview-toolbar #exportPageBtn {
        display: none !important;
    }
    .preview-toolbar .settings-toggle-btn { order: 0; }
    .preview-toolbar .toolbar-group:last-of-type { order: 1; }
    .preview-toolbar .toolbar-group:first-of-type { order: 2; }
    .toolbar-group {
        gap: 6px;
        flex-shrink: 0;
    }
    .preview-toolbar .btn {
        padding: 8px 12px;
        font-size: 12px;
        white-space: nowrap;
        min-height: 36px;
        min-width: 44px;
    }
    .preview-toolbar .page-info {
        font-size: 12px;
        flex: 0 1 auto;
        min-width: 0;
        text-align: center;
        order: 3;
        margin-top: 0;
    }
    .preview-area {
        padding: 8px 12px;
    }
    .device-skin-switch {
        top: 8px;
        right: 12px;
    }
    .progress-container:not(.export-progress-overlay) {
        padding: 12px 16px;
        padding-bottom: calc(12px + env(safe-area-inset-bottom, 20px));
    }
    .block-config-footer {
        padding-left: 0;
        padding-right: 0;
    }
}

/* 小屏手机：整体再缩小，输入框 16px 防 iOS 放大 */
@media (max-width: 480px) {
    .screen-preset-row,
    .text-size-preset-row {
        gap: 5px;
    }
    .preset-btn {
        padding: 7px 5px;
    }
    .preset-icon {
        font-size: 15px;
    }
    .preset-name {
        font-size: 9px;
    }
    .quality-buttons {
        gap: 6px;
    }
    .quality-btn {
        padding: 8px 6px;
        min-height: 52px;
        gap: 3px;
    }
    .quality-btn-desc {
        font-size: 11px;
    }
    .quality-btn-hint {
        font-size: 8px;
        line-height: 1.2;
    }

    .app-bar {
        padding: 6px 12px;
    }
    .app-title {
        font-size: 14px;
    }
    .app-title-short {
        font-size: 14px;
    }
    .app-subtitle {
        font-size: 9px;
    }
    .app-subtitle-long {
        display: none;
    }
    .app-subtitle-short {
        display: block;
    }
    .lang-btn {
        padding: 6px 10px;
        font-size: 12px;
    }
    .tech-modal {
        padding: 12px;
    }
    .tech-modal-card {
        width: 100%;
        max-height: 82vh;
        border-radius: 10px;
        padding: 12px;
    }
    .tech-modal-head h3 {
        font-size: 15px;
    }
    .tech-modal-desc,
    .tech-modal-subtitle,
    .tech-modal-list li,
    .export-confirm-row,
    .export-confirm-question {
        font-size: 12px;
    }
    .panel-left {
        width: 100%;
        min-width: 0;
        max-width: none;
        max-height: 38vh;
        padding: 8px 12px;
    }
    .panel-left .section-head {
        font-size: 10px;
        padding: 6px 8px;
    }
    .block-book {
        padding: 8px 10px;
        margin-bottom: 8px;
    }
    .book-title {
        font-size: 13px;
    }
    .book-author {
        font-size: 11px;
    }
    .drop-zone {
        padding: 10px 8px;
    }
    .drop-zone-icon {
        font-size: 20px;
    }
    .drop-zone-text {
        font-size: 11px;
    }
    .file-list {
        max-height: 80px;
    }
    .file-item {
        padding: 6px 8px;
        font-size: 11px;
    }
    /* tabs - 注释掉
    .tabs .tab-btn {
        padding: 6px 8px;
        font-size: 11px;
    }
    */
    .panel-left .control-group select {
        padding: 8px 10px;
        font-size: 14px;
        min-height: 36px;
    }
    .panel-left .control-group input[type="text"],
    .panel-left .control-group input[type="number"] {
        padding: 8px 10px;
        font-size: 16px;
        min-height: 36px;
    }
    .slider-row input[type="number"] {
        width: 50px;
    }
    input[type="range"]::-webkit-slider-thumb {
        width: 18px;
        height: 18px;
    }
    .orientation-buttons-block .orientation-btn {
        padding: 8px 4px;
        font-size: 11px;
        min-height: 36px;
    }
    .chapter-list {
        max-height: 100px;
    }
    .chapter-item {
        padding: 8px 10px;
        font-size: 12px;
    }
    .panel-left .checkbox-group input[type="checkbox"] {
        width: 16px;
        height: 16px;
    }
    .panel-left .checkbox-group label {
        font-size: 12px;
    }
    .progress-line-label,
    .optimizer-desc {
        font-size: 11px;
    }
    #optimizeBtn {
        padding: 10px 16px;
        font-size: 14px;
        min-height: 40px;
    }
    .preview-toolbar {
        padding: 6px 12px;
    }
    .preview-toolbar .btn {
        padding: 6px 10px;
        font-size: 11px;
        min-height: 32px;
    }
    .preview-area {
        padding: 8px 12px;
    }
    .device-skin-switch {
        top: 8px;
        right: 8px;
    }
    .progress-container:not(.export-progress-overlay) {
        padding: 10px 12px;
        padding-bottom: calc(10px + env(safe-area-inset-bottom, 20px));
    }
    .compliance-text--sidebar {
        font-size: 10px;
    }
}