:root {
    --primary-color: #1a365d;
    --primary-light: #2c5282;
    --primary-dark: #12283a;
    --accent-color: #3182ce;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --sidebar-bg: #edf2f7;
    --text-main: #2d3748;
    --text-muted: #718096;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --input-bg: rgba(255,255,255,0.95);
    --overlay-bg: rgba(255,255,255,0.9);
}

[data-theme="dark"] {
    --primary-color: #1e293b;
    --primary-light: #334155;
    --primary-dark: #0f172a;
    --accent-color: #60a5fa;
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --sidebar-bg: #1e293b;
    --text-main: #e2e8f0;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -1px rgba(0,0,0,0.2);
    --input-bg: #334155;
    --overlay-bg: rgba(15,23,42,0.9);
}

[data-theme="dark"] .advanced-search-panel {
    background: var(--primary-dark);
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .advanced-search-panel .search-field label {
    color: var(--text-muted);
}

[data-theme="dark"] .advanced-search-panel input,
[data-theme="dark"] .advanced-search-panel select {
    background: var(--input-bg);
    color: var(--text-main);
    border-color: var(--border-color);
}

[data-theme="dark"] .advanced-search-panel input:focus,
[data-theme="dark"] .advanced-search-panel select:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(96, 165, 250, 0.3);
}

[data-theme="dark"] .adv-clear-btn {
    color: var(--text-muted);
    border-color: var(--border-color);
}

[data-theme="dark"] .adv-clear-btn:hover {
    background: var(--input-bg);
    color: var(--text-main);
}

[data-theme="dark"] .advanced-search-toggle.active {
    background: rgba(96, 165, 250, 0.25);
    border-color: var(--accent-color);
}

[data-theme="dark"] #searchInput {
    background: var(--input-bg);
    color: var(--text-main);
}

[data-theme="dark"] #searchInput:focus {
    background: #475569;
    box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.4);
}

[data-theme="dark"] .law-card {
    background: var(--card-bg);
}

[data-theme="dark"] .law-card:hover {
    border-color: var(--accent-color);
    box-shadow: 0 4px 12px rgba(0,0,0,0.4);
}

[data-theme="dark"] .law-card h4 {
    color: #e2e8f0;
}

[data-theme="dark"] .law-detail-header h2 {
    color: #e2e8f0;
}

[data-theme="dark"] .law-level-badge {
    background: #1e3a5f;
    color: #93c5fd;
}

[data-theme="dark"] .results-area {
    background-color: var(--bg-color);
}

[data-theme="dark"] .detail-view {
    background: var(--card-bg);
    box-shadow: -4px 0 15px rgba(0,0,0,0.4);
}

[data-theme="dark"] .detail-toolbar {
    background: var(--primary-dark);
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .detail-search-box input,
[data-theme="dark"] .sidebar-search input {
    background: var(--input-bg);
    color: var(--text-main);
    border-color: var(--border-color);
}

[data-theme="dark"] .detail-nav-btn {
    background: var(--input-bg);
    color: var(--text-muted);
    border-color: var(--border-color);
}

[data-theme="dark"] .overlay {
    background: var(--overlay-bg);
}

[data-theme="dark"] .tree-toggle {
    background: var(--primary-dark);
    color: var(--text-muted);
    border-color: #475569;
}

[data-theme="dark"] .count-badge {
    background-color: #0891b2;
}

[data-theme="dark"] .article-item {
    border-left-color: #475569;
}

[data-theme="dark"] .article-item.header {
    border-left-color: var(--accent-color);
    background: #1e293b;
}

[data-theme="dark"] mark.search-highlight {
    background-color: #854d0e;
    color: #fef3c7;
}

[data-theme="dark"] mark.search-highlight.active {
    background-color: #c2410c;
    outline-color: #f97316;
}

[data-theme="dark"] .btn-primary {
    background-color: var(--accent-color);
}

[data-theme="dark"] .btn-primary:hover {
    background-color: #3b82f6;
}

[data-theme="dark"] .btn-outline {
    color: var(--text-main);
    border-color: var(--border-color);
}

[data-theme="dark"] .detail-view .btn-outline {
    color: var(--accent-color);
    border-color: var(--accent-color);
}

[data-theme="dark"] .detail-view .btn-outline:hover {
    background-color: #1e3a5f;
}

[data-theme="dark"] .action-btn.secondary {
    background-color: #1e3a5f;
    color: var(--accent-color);
    border-color: var(--accent-color);
}

[data-theme="dark"] .action-btn.secondary:hover {
    background-color: var(--accent-color);
    color: white;
}

[data-theme="dark"] .action-btn.primary {
    background-color: var(--accent-color);
}

/* Theme Toggle Button */
.theme-toggle {
    background: none;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.1rem;
    padding: 0.3rem 0.5rem;
    transition: var(--transition);
    line-height: 1;
}

.theme-toggle:hover {
    background: rgba(255,255,255,0.1);
    transform: scale(1.1);
}

* {
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', 'Noto Sans TC', system-ui, -apple-system, sans-serif;
    color: var(--text-main);
    background-color: var(--bg-color);
    overflow: hidden; /* App handle scrolling */
    line-height: 1.6;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* Header Styles */
.app-header {
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: var(--shadow-md);
    z-index: 100;
}

.logo-section h1 {
    font-size: 1.25rem;
    font-weight: 700;
}

.version-tag {
    font-size: 0.7rem;
    opacity: 0.7;
    background: rgba(255,255,255,0.1);
    padding: 2px 6px;
    border-radius: 4px;
}

.search-section {
    flex: 1;
    max-width: 600px;
    margin: 0 2rem;
}

.search-container {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 12px;
    width: 18px;
    height: 18px;
    color: var(--text-muted);
}

#searchInput {
    width: 100%;
    padding: 0.6rem 1rem 0.6rem 2.5rem;
    border: none;
    border-radius: 8px;
    background: rgba(255,255,255,0.95);
    font-size: 0.95rem;
    color: var(--text-main);
    transition: var(--transition);
}

#searchInput:focus {
    outline: none;
    background: white;
    box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.5);
}

#searchInput:disabled {
    cursor: not-allowed;
    opacity: 0.6;
}

/* Advanced Search Toggle Button */
.advanced-search-toggle {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.45rem 0.85rem;
    border: 1px solid rgba(255,255,255,0.25);
    border-radius: 8px;
    background: rgba(255,255,255,0.08);
    color: rgba(255,255,255,0.85);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    margin-left: 0.5rem;
    flex-shrink: 0;
}

.advanced-search-toggle:hover:not(:disabled) {
    background: rgba(255,255,255,0.18);
    border-color: rgba(255,255,255,0.5);
    transform: translateY(-1px);
}

.advanced-search-toggle:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.advanced-search-toggle.active {
    background: rgba(49, 130, 206, 0.3);
    border-color: var(--accent-color);
    color: white;
    box-shadow: 0 0 8px rgba(49, 130, 206, 0.3);
}

.advanced-search-toggle svg {
    flex-shrink: 0;
}

/* Advanced Search Panel */
.advanced-search-panel {
    max-height: 0;
    overflow: hidden;
    background: linear-gradient(135deg, #1a365d 0%, #12283a 100%);
    border-bottom: 2px solid transparent;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                border-bottom-color 0.3s ease,
                padding 0.3s ease;
}

.advanced-search-panel.open {
    max-height: 400px;
    border-bottom-color: var(--accent-color);
}

.advanced-search-inner {
    padding: 1.25rem 1.5rem;
}

.advanced-search-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.search-field label {
    display: block;
    font-size: 0.78rem;
    font-weight: 600;
    color: rgba(255,255,255,0.7);
    margin-bottom: 0.3rem;
    letter-spacing: 0.03em;
}

.search-field input,
.search-field select {
    width: 100%;
    padding: 0.45rem 0.65rem;
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 6px;
    background: rgba(255,255,255,0.1);
    color: white;
    font-size: 0.88rem;
    transition: var(--transition);
    box-sizing: border-box;
}

.search-field input::placeholder {
    color: rgba(255,255,255,0.4);
}

.search-field input:focus,
.search-field select:focus {
    outline: none;
    border-color: var(--accent-color);
    background: rgba(255,255,255,0.15);
    box-shadow: 0 0 0 2px rgba(49, 130, 206, 0.35);
}

.search-field select option {
    background: #1a365d;
    color: white;
}

.date-range {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.date-range input {
    flex: 1;
    min-width: 0;
}

.date-separator {
    color: rgba(255,255,255,0.5);
    font-size: 0.9rem;
    flex-shrink: 0;
}

.advanced-search-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 1rem;
    padding-top: 0.75rem;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.adv-clear-btn {
    color: rgba(255,255,255,0.7) !important;
    border-color: rgba(255,255,255,0.25) !important;
}

.adv-clear-btn:hover {
    background: rgba(255,255,255,0.1) !important;
    color: white !important;
}

.adv-search-status {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.65);
    margin-left: auto;
    font-style: italic;
}

.results-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

.action-btn.secondary {
    background-color: #ebf8ff;
    color: var(--accent-color);
    border-color: var(--accent-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.action-btn.secondary:hover {
    background-color: var(--accent-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.actions-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.btn {
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background-color: var(--accent-color);
    color: white;
}

.btn-primary:hover {
    background-color: #2b6cb0;
}

.btn-outline {
    background-color: transparent;
    color: white;
    border: 1px solid rgba(255,255,255,0.3);
}

.btn-outline:hover {
    background-color: rgba(255,255,255,0.1);
}

.detail-view .btn-outline {
    color: var(--accent-color);
    border-color: var(--accent-color);
}

.detail-view .btn-outline:hover {
    background-color: #ebf8ff;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: #cbd5e0;
}

.status-indicator.ready .status-dot { background-color: #48bb78; box-shadow: 0 0 8px #48bb78; }
.status-indicator.warning .status-dot { background-color: #f6ad55; }
.status-indicator.warning .status-text { color: #dd6b20; font-weight: 600; }

/* Layout */
.app-content {
    display: flex;
    flex: 1;
    overflow: hidden;
    position: relative;
}

.sidebar {
    width: 280px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    padding: 1.5rem;
    overflow-y: auto;
}

.sidebar-section {
    margin-bottom: 2rem;
}

.sidebar-section h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.filter-group.scrollable {
    max-height: 60vh;
    overflow-y: auto;
    padding-right: 5px;
}

/* Tree Styles */
.tree-node {
    margin-bottom: 0;
}

.tree-header {
    display: flex;
    align-items: center;
    padding: 1px 0;
}

.tree-toggle {
    cursor: pointer;
    font-size: 1rem;
    width: 14px;
    height: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4a5568;
    border: 1px solid #a0aec0;
    border-radius: 2px;
    margin-right: 6px;
    font-family: monospace;
    line-height: 1;
    background: #f7fafc;
    flex-shrink: 0;
}

.tree-toggle:hover {
    color: var(--primary-color);
}

.tree-spacer {
    width: 20px;
}

.tree-dl-btn {
    cursor: pointer;
    font-size: 0.8rem;
    margin-left: 5px;
    opacity: 0.4;
    transition: var(--transition);
}

.tree-header:hover .tree-dl-btn {
    opacity: 1;
}

.tree-dl-btn:hover {
    transform: scale(1.2);
}

.tree-children {
    padding-left: 18px;
    border-left: 1px dotted #cbd5e0;
    margin-left: 8px;
}

.tree-children.hidden {
    display: none;
}

.depth-1 > .tree-header { font-weight: 500; }
.depth-2 { margin-left: 5px; }
.depth-2 > .tree-children {
    padding-left: 8px; /* 減少縮排，使其更靠左 */
    border-left: none; /* 移除邊線以節省空間 */
}

.filter-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.85rem;
    cursor: pointer;
    padding: 1px 4px;
    border-radius: 4px;
    transition: var(--transition);
    flex: 1;
    line-height: 1.2;
}

.tree-node-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.count-badge {
    background-color: #00bcd4; /* Cyan color like in the reference */
    color: white;
    font-size: 0.65rem;
    padding: 2px 6px;
    border-radius: 12px;
    min-width: 22px;
    text-align: center;
    font-weight: 600;
    margin-left: auto;
}

.tree-header:hover .count-badge {
    opacity: 1;
    transform: scale(1.1);
}

.filter-item:hover {
    background: rgba(0,0,0,0.05);
}

.filter-item input {
    cursor: pointer;
}

/* Results Area */
.results-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: white;
}

.results-header {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.results-list {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
}

.law-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.law-card:hover {
    border-color: var(--accent-color);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.law-card-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.law-level-badge {
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 12px;
    background: #ebf8ff;
    color: #2b6cb0;
    font-weight: 500;
}

.law-card h4 {
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.law-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
    display: flex;
    gap: 1.5rem;
}

.law-card-extra {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px dashed var(--border-color);
    font-size: 0.8rem;
    line-height: 1.5;
}

.extra-label {
    flex-shrink: 0;
    font-weight: 600;
    color: var(--accent-color);
    font-size: 0.75rem;
}

.extra-text {
    color: var(--text-muted);
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-muted);
    text-align: center;
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
}

/* Tutorial Page (before data load) */
.tutorial-page {
    flex: 1;
    overflow-y: auto;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 2rem 1.5rem;
    background-color: var(--bg-color);
}

.tutorial-page .empty-state {
    height: auto;
}

/* Tutorial Section */
.tutorial-section {
    margin-top: 2rem;
    text-align: left;
    max-width: 600px;
    width: 100%;
}

.tutorial-section h3 {
    font-size: 1.1rem;
    color: var(--text-main);
    margin-bottom: 0.5rem;
}

.tutorial-subtitle {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1.25rem;
}

.tutorial-subtitle a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
}

.tutorial-subtitle a:hover {
    text-decoration: underline;
}

.tutorial-steps {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.tutorial-step {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    background: var(--sidebar-bg);
    border-radius: 10px;
    padding: 1rem;
    border: 1px solid var(--border-color);
}

.step-number {
    width: 28px;
    height: 28px;
    min-width: 28px;
    border-radius: 50%;
    background: var(--accent-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
}

.step-content {
    flex: 1;
}

.step-content strong {
    display: block;
    margin-bottom: 0.3rem;
    color: var(--text-main);
}

.step-content p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
}

.api-url {
    display: block;
    background: var(--primary-dark, #12283a);
    color: #93c5fd;
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
    font-size: 0.8rem;
    word-break: break-all;
    margin-bottom: 0.3rem;
    font-family: 'Consolas', 'Monaco', monospace;
}

.api-note {
    font-size: 0.75rem;
    color: #f6ad55;
}

.tutorial-details {
    margin-top: 1.25rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.tutorial-details summary {
    padding: 0.6rem 1rem;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    background: var(--sidebar-bg);
    color: var(--text-main);
}

.tutorial-details summary:hover {
    background: var(--border-color);
}

.tutorial-details[open] summary {
    border-bottom: 1px solid var(--border-color);
}

.api-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8rem;
    margin-top: 0;
}

.api-table th, .api-table td {
    padding: 0.5rem 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.api-table th {
    background: var(--sidebar-bg);
    font-weight: 600;
    color: var(--text-muted);
}

.api-table td {
    color: var(--text-main);
}

.api-table code {
    background: var(--primary-dark, #12283a);
    color: #93c5fd;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.75rem;
}

.shadow-pulse {
    animation: shadow-pulse 2s infinite;
}

@keyframes shadow-pulse {
    0% { filter: drop-shadow(0 0 0 rgba(0,0,0,0.1)); }
    50% { filter: drop-shadow(0 10px 20px rgba(0,0,0,0.05)); }
    100% { filter: drop-shadow(0 0 0 rgba(0,0,0,0.1)); }
}

/* Detail View */
.detail-view {
    position: absolute;
    top: 0;
    right: -100%;
    width: 60%;
    height: 100%;
    background: white;
    box-shadow: -4px 0 15px rgba(0,0,0,0.1);
    z-index: 50;
    transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
}

.detail-view.active {
    right: 0;
}

.close-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 2rem;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    z-index: 60;
}

.detail-content {
    flex: 1;
    overflow-y: auto;
    padding: 3rem 2.5rem;
}

.law-detail-header {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1.5rem;
    margin-bottom: 2rem;
}

.law-detail-header h2 {
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.law-full-meta {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.law-info-item strong {
    color: var(--text-main);
    display: block;
}

/* Foreword & History Sections */
.law-foreword-section,
.law-history-section {
    margin-top: 1.5rem;
}

.section-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: default;
}

.foreword-content {
    background: #f0f7ff;
    border-left: 4px solid var(--accent-color);
    padding: 1rem 1.25rem;
    border-radius: 0 8px 8px 0;
    font-size: 0.95rem;
    line-height: 1.8;
    white-space: pre-wrap;
    color: var(--text-main);
}

.history-details {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.history-details summary.section-title {
    padding: 0.75rem 1rem;
    margin-bottom: 0;
    cursor: pointer;
    background: var(--sidebar-bg);
    border-radius: 8px;
    transition: var(--transition);
    user-select: none;
}

.history-details summary.section-title:hover {
    background: var(--border-color);
}

.history-details[open] summary.section-title {
    border-radius: 8px 8px 0 0;
    border-bottom: 1px solid var(--border-color);
}

.history-content {
    padding: 1rem 1.25rem;
    font-size: 0.9rem;
    line-height: 1.8;
    white-space: pre-wrap;
    color: var(--text-muted);
    max-height: 400px;
    overflow-y: auto;
}

[data-theme="dark"] .foreword-content {
    background: rgba(96, 165, 250, 0.08);
    border-left-color: var(--accent-color);
}

[data-theme="dark"] .history-details {
    border-color: var(--border-color);
}

[data-theme="dark"] .history-details summary.section-title {
    background: var(--primary-dark);
}

[data-theme="dark"] .history-details summary.section-title:hover {
    background: var(--border-color);
}

[data-theme="dark"] .section-title {
    color: var(--accent-color);
}

.download-btns-group {
    display: flex;
    gap: 0.5rem;
}

.download-btn {
    font-size: 0.8rem !important;
    white-space: nowrap;
    border-color: rgba(255,255,255,0.3) !important;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.article-section {
    margin-top: 2rem;
}

.article-item {
    margin-bottom: 2rem;
    padding-left: 1rem;
    border-left: 3px solid #e2e8f0;
}

.article-item.header {
    border-left-color: var(--accent-color);
    font-weight: 700;
    font-size: 1.2rem;
    background: #f7fafc;
    padding: 1rem;
    margin-left: -1rem;
}

.article-no {
    color: var(--accent-color);
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.article-content {
    white-space: pre-wrap;
    font-size: 1.05rem;
}

/* Loading Overlay */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.hidden {
    display: none;
}

.loader-content {
    text-align: center;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid var(--border-color);
    border-top: 5px solid var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1.5rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.progress-bar {
    width: 300px;
    height: 6px;
    background: #e2e8f0;
    border-radius: 3px;
    margin-top: 1rem;
    overflow: hidden;
}

#progressFill {
    height: 100%;
    width: 0%;
    background: var(--accent-color);
    transition: width 0.3s;
}

.action-btn.primary {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.action-btn.primary:hover {
    background-color: #2b6cb0;
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

/* Sidebar Search */
.sidebar-search {
    margin-bottom: 0.75rem;
}

.sidebar-search input {
    width: 100%;
    padding: 0.4rem 0.6rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.85rem;
    background: white;
    color: var(--text-main);
    transition: var(--transition);
}

.sidebar-search input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(66, 153, 225, 0.3);
}

/* Search Highlight */
mark.search-highlight {
    background-color: #fefcbf;
    color: inherit;
    padding: 0 2px;
    border-radius: 2px;
}

mark.search-highlight.active {
    background-color: #f6ad55;
    outline: 2px solid #dd6b20;
}

/* Detail Toolbar */
.detail-toolbar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 2.5rem;
    border-bottom: 1px solid var(--border-color);
    background: var(--sidebar-bg);
}

.detail-search-box {
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.detail-search-box input {
    padding: 0.35rem 0.6rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.85rem;
    width: 200px;
    background: white;
    color: var(--text-main);
}

.detail-search-box input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(66, 153, 225, 0.3);
}

.detail-search-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    min-width: 50px;
    text-align: center;
}

.detail-nav-btn {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 2px 6px;
    cursor: pointer;
    font-size: 0.7rem;
    color: var(--text-muted);
    transition: var(--transition);
}

.detail-nav-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

/* Responsive Overhaul */
@media (max-width: 768px) {
    .app-header {
        flex-direction: column;
        padding: 0.75rem;
        gap: 0.75rem;
    }

    .header-main-actions {
        display: flex;
        flex-wrap: wrap;
        gap: 0.5rem;
        justify-content: center;
        width: 100%;
    }

    .header-main-actions .btn {
        flex: 1;
        min-width: 140px;
        font-size: 0.85rem;
        padding: 0.5rem;
        white-space: nowrap;
    }

    .download-btns-group {
        width: 100%;
        justify-content: center;
    }

    .search-section {
        width: 100%;
        margin: 0;
    }

    .search-container {
        width: 100%;
    }

    /* Mobile Content Layout - FORCE SCROLL CHAIN */
    .app-content {
        position: relative;
        flex-direction: column;
        flex: 1;
        overflow: hidden; /* This forces children to handle their own overflow */
        height: initial; /* Revert to auto behavior within flex context */
    }

    .results-area {
        height: 100%;
        overflow: hidden;
    }


    .sidebar {
        position: fixed;
        top: 0;
        left: -100%;
        width: 85%;
        height: 100%;
        z-index: 1001;
        background: var(--card-bg);
        box-shadow: 2px 0 10px rgba(0,0,0,0.2);
        transition: left 0.3s ease;
        padding-top: 4rem;
        max-height: none;
    }

    .sidebar.active {
        left: 0;
    }

    /* Sidebar Toggle Button */
    .sidebar-toggle-mobile {
        display: flex !important;
        align-items: center;
        justify-content: center;
        padding: 0.4rem 0.8rem;
        font-size: 0.9rem;
    }

    /* Close button for sidebar on mobile */
    .sidebar::after {
        content: '✕ 關閉篩選';
        position: absolute;
        top: 1rem;
        right: 1rem;
        padding: 0.5rem 1rem;
        background: var(--sidebar-bg);
        border-radius: 20px;
        font-size: 0.8rem;
        color: var(--text-muted);
        cursor: pointer;
    }

    /* Results Header */
    .results-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
        padding: 0.75rem;
    }

    .results-actions {
        width: 100%;
        justify-content: space-between;
    }

    .results-actions .action-btn {
        flex: 1;
        font-size: 0.75rem;
        padding: 0.4rem;
    }

    /* Detail View Mobile */
    .detail-view {
        width: 100% !important;
        height: 100%;
        top: 0;
        right: -100%;
        border-left: none;
    }

    .detail-view.active {
        right: 0;
    }

    .detail-toolbar {
        padding: 0.5rem;
        position: sticky;
        top: 0;
        z-index: 10;
        flex-wrap: wrap;
    }

    .detail-search-box {
        width: 100%;
    }

    .detail-search-box input {
        width: 0;
        flex-grow: 1;
    }

    .detail-content {
        padding: 1rem;
    }

    .law-detail-header h2 {
        font-size: 1.4rem;
    }

    .law-full-meta {
        grid-template-columns: 1fr;
    }

    /* Advanced Search Grid */
    .advanced-search-grid {
        grid-template-columns: 1fr;
        padding: 1rem;
    }
    
    .advanced-search-actions {
        flex-direction: column;
        gap: 1rem;
    }
}

/* Dropdown Menu System */
.dropdown-container {
    position: relative;
    display: inline-block;
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + 10px);
    right: 0;
    width: 240px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    z-index: 1002;
    padding: 0.75rem 0;
    display: none;
    flex-direction: column;
    animation: dropdownFadeIn 0.2s ease-out;
}

.dropdown-menu.active {
    display: flex;
}

@keyframes dropdownFadeIn {
    from { opacity: 0; margin-top: -10px; }
    to { opacity: 1; margin-top: 0; }
}

.dropdown-group {
    padding: 0.5rem 0;
}

.dropdown-title {
    padding: 0.25rem 1.25rem;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.dropdown-item, .dropdown-item-btn {
    display: flex;
    align-items: center;
    padding: 0.6rem 1.25rem;
    font-size: 0.9rem;
    color: var(--text-main);
    text-decoration: none;
    transition: var(--transition);
    border: none;
    background: transparent;
    width: 100%;
    text-align: left;
    cursor: pointer;
}

.dropdown-item:hover, .dropdown-item-btn:hover {
    background: var(--sidebar-bg);
    color: var(--accent-color);
}

.dropdown-divider {
    height: 1px;
    background: var(--border-color);
    margin: 0.5rem 0;
}

.danger-text {
    color: #e53e3e !important;
}

.danger-text:hover {
    background: #fff5f5 !important;
}

[data-theme="dark"] .danger-text:hover {
    background: #442222 !important;
}

/* Data Menu Button Specifics */
.data-menu-btn {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.3) !important;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Responsive Adjustments for Dropdown */
@media (max-width: 768px) {
    .actions-section {
        display: flex;
        width: 100%;
        justify-content: center;
        gap: 0.5rem;
    }

    .dropdown-container {
        position: relative; /* Keep it relative for absolute positioning of children */
        flex: 1;
    }
    
    .data-menu-btn {
        width: 100%;
        justify-content: center;
    }

    .dropdown-menu {
        width: 280px; /* Specific width on mobile */
        right: 50%;
        transform: translateX(50%);
        top: calc(100% + 10px);
        border-radius: 12px;
        box-shadow: 0 10px 25px rgba(0,0,0,0.3);
    }
}