:root {
    --color-bg: #faf9f7;
    --color-surface: #ffffff;
    --color-border: #e8e6e3;
    --color-text: #1a1a1a;
    --color-text-muted: #78756e;
    --color-accent: #c9a86c;
    --color-accent-hover: #b8955a;
    --color-danger: #d45c5c;
    --sidebar-width: 420px;
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-medium: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.main-container {
    display: flex;
    height: 100vh;
    gap: 1px;
    background: var(--color-border);
}

.sidebar {
    width: var(--sidebar-width);
    background: var(--color-surface);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.sidebar-header {
    padding: 32px 32px 24px;
    border-bottom: 1px solid var(--color-border);
}

.sidebar-header h1 {
    font-family: 'Space Grotesk', 'Noto Sans SC', sans-serif;
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin: 0 0 4px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-mark {
    font-size: 22px;
    line-height: 1;
    color: var(--color-accent);
}

.subtitle {
    font-size: 13px;
    color: var(--color-text-muted);
    margin: 0;
    letter-spacing: 0.02em;
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 24px 32px 32px;
}

.drop-zone {
    border: 2px dashed var(--color-border);
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-medium);
    margin: 0 32px 24px;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--color-accent);
    background: rgba(201, 168, 108, 0.05);
}

.drop-zone-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 12px;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

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

.drop-zone-text {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 4px;
}

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

.file-input {
    display: none;
}

.file-list {
    border: 1px solid var(--color-border);
    border-radius: 12px;
    margin: 0 32px 24px;
    overflow: hidden;
}

.file-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
}

.file-list-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-muted);
}

.file-list-title i {
    font-size: 14px;
}

.btn-clear {
    width: 28px;
    height: 28px;
    border: none;
    background: transparent;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    transition: all var(--transition-fast);
}

.btn-clear:hover {
    background: var(--color-danger);
    color: white;
}

.file-list-items {
    max-height: 160px;
    overflow-y: auto;
}

.file-item {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    cursor: pointer;
    border-bottom: 1px solid var(--color-border);
    font-size: 13px;
    transition: background var(--transition-fast);
}

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

.file-item:hover {
    background: var(--color-bg);
}

.file-item.active {
    background: rgba(201, 168, 108, 0.1);
    color: var(--color-accent);
}

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

.file-item .file-remove {
    margin-left: 8px;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    color: var(--color-text-muted);
    font-size: 18px;
    line-height: 1;
    transition: all var(--transition-fast);
}

.file-item .file-remove:hover {
    background: var(--color-danger);
    color: white;
}

.settings-section {
    padding: 0 32px;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding-top: 24px;
}

.section-header:first-of-type {
    padding-top: 0;
}

.section-number {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 11px;
    font-weight: 600;
    color: var(--color-accent);
    letter-spacing: 0.1em;
}

.section-title {
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-text-muted);
}

.section-content {
    padding-bottom: 8px;
}

.form-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 8px;
    display: block;
}

.form-select,
.form-control {
    width: 100%;
    padding: 10px 14px;
    font-size: 14px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    background: var(--color-surface);
    color: var(--color-text);
    transition: all var(--transition-fast);
    font-family: inherit;
}

.form-select:focus,
.form-control:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(201, 168, 108, 0.15);
}

.form-select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3E%3Cpath fill='%2378756e' d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 12px;
    padding-right: 36px;
}

.form-select:focus {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3E%3Cpath fill='%23c9a86c' d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
}

.orientation-buttons {
    display: flex;
    gap: 12px;
}

.orientation-btn {
    flex: 1;
    padding: 16px 12px;
    border: 2px solid var(--color-border);
    border-radius: 12px;
    background: var(--color-surface);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    color: var(--color-text-muted);
}

.orientation-btn:hover {
    border-color: var(--color-accent);
    color: var(--color-text);
}

.orientation-btn.active {
    border-color: var(--color-accent);
    background: rgba(201, 168, 108, 0.1);
    color: var(--color-accent);
}

.slider-group {
    margin-bottom: 8px;
}

.slider-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.slider-label span:first-child {
    font-size: 13px;
    font-weight: 500;
}

.slider-value {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 13px;
    font-weight: 600;
    color: var(--color-accent);
}

.range-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.form-range {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--color-border);
    -webkit-appearance: none;
    appearance: none;
}

.form-range::-webkit-slider-runnable-track {
    height: 6px;
    border-radius: 3px;
    background: var(--color-border);
}

.form-range::-moz-range-track {
    height: 6px;
    border-radius: 3px;
    background: var(--color-border);
}

.form-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-accent);
    border: 3px solid var(--color-surface);
    box-shadow: 0 2px 8px rgba(201, 168, 108, 0.3);
    cursor: pointer;
    margin-top: -6px;
    transition: transform var(--transition-fast);
}

.form-range::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.form-range::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-accent);
    border: 3px solid var(--color-surface);
    box-shadow: 0 2px 8px rgba(201, 168, 108, 0.3);
    cursor: pointer;
    transition: transform var(--transition-fast);
}

.form-range::-moz-range-thumb:hover {
    transform: scale(1.1);
}

.range-group .form-control {
    width: 70px;
    text-align: center;
    padding: 8px 10px;
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 500;
}

.form-check {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.form-check-input {
    width: 18px;
    height: 18px;
    border: 2px solid var(--color-border);
    border-radius: 4px;
    background: var(--color-surface);
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.form-check-input:checked {
    background: var(--color-accent);
    border-color: var(--color-accent);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='white' d='M9.293 3.293L4 8.586 2.707 7.293a1 1 0 00-1.414 1.414l2 2a1 1 0 001.414 0l6-6a1 1 0 00-1.414-1.414z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: center;
    background-size: 12px;
}

.form-check-label {
    font-size: 13px;
    color: var(--color-text);
    cursor: pointer;
    user-select: none;
}

.btn-upload {
    width: 100%;
    padding: 12px 16px;
    border: 1px dashed var(--color-border);
    border-radius: 10px;
    background: var(--color-bg);
    color: var(--color-text);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all var(--transition-fast);
}

.btn-upload:hover {
    border-color: var(--color-accent);
    background: rgba(201, 168, 108, 0.05);
    color: var(--color-accent);
}

.custom-font-name {
    margin-top: 8px;
    font-size: 12px;
    text-align: center;
}

.dithering-controls {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px 16px;
}

.chapter-list {
    border: 1px solid var(--color-border);
    border-radius: 12px;
    max-height: 200px;
    overflow-y: auto;
}

.chapter-placeholder {
    padding: 20px 16px;
    text-align: center;
    font-size: 13px;
    color: var(--color-text-muted);
}

.chapter-item {
    padding: 10px 16px;
    cursor: pointer;
    border-bottom: 1px solid var(--color-border);
    font-size: 13px;
    transition: background var(--transition-fast);
}

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

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

.chapter-item.active {
    background: rgba(201, 168, 108, 0.1);
    color: var(--color-accent);
    font-weight: 500;
}

.progress-container {
    padding: 0 32px 24px;
}

.progress-bar-wrapper {
    margin-bottom: 8px;
}

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

.progress-bar-fill {
    height: 100%;
    background: var(--color-accent);
    border-radius: 3px;
    transition: width 0.3s ease;
}

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

.export-section {
    padding: 0 32px 24px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.btn-primary,
.btn-secondary,
.btn-outline {
    width: 100%;
    padding: 14px 20px;
    border: none;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all var(--transition-medium);
    font-family: inherit;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--color-accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(201, 168, 108, 0.3);
}

.btn-secondary {
    background: var(--color-text);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(26, 26, 26, 0.2);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text);
}

.btn-outline:hover:not(:disabled) {
    border-color: var(--color-accent);
    color: var(--color-accent);
    background: rgba(201, 168, 108, 0.05);
}

.btn-primary:disabled,
.btn-secondary:disabled,
.btn-outline:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.sidebar-footer {
    padding: 0 32px 32px;
    margin-top: auto;
}

.footer-line {
    height: 1px;
    background: var(--color-border);
    margin-bottom: 16px;
}

.footer-text {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    color: var(--color-text-muted);
}

.footer-text a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.footer-text a:hover {
    color: var(--color-accent-hover);
    text-decoration: underline;
}

.content-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--color-surface);
    overflow: hidden;
}

.preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 20px 32px;
    border-bottom: 1px solid var(--color-border);
}

.preview-nav {
    display: flex;
    gap: 12px;
}

.btn-nav {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 16px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: inherit;
}

.btn-nav:hover:not(:disabled) {
    border-color: var(--color-accent);
    background: rgba(201, 168, 108, 0.05);
    color: var(--color-accent);
}

.btn-nav:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.preview-page-info {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--color-text-muted);
}

.page-numbers {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
}

.book-info {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.book-meta {
    text-align: right;
}

.book-title {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 2px;
}

.book-author {
    display: block;
    font-size: 12px;
    color: var(--color-text-muted);
}

.book-author .by,
.book-author .pages {
    opacity: 0.6;
}

.book-author .dot {
    margin: 0 6px;
    opacity: 0.4;
}

.book-author span {
    margin: 0 2px;
}

.btn-refresh {
    width: 40px;
    height: 40px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    background: var(--color-surface);
    color: var(--color-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

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

.btn-refresh:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.preview-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
    overflow: hidden;
    position: relative;
    background: linear-gradient(135deg, #faf9f7 0%, #f5f3ef 100%);
}

.preview-wrapper {
    max-width: 100%;
    max-height: 100%;
}

.device-frame {
    background: linear-gradient(145deg, #2a2a2a, #1a1a1a);
    border-radius: 28px;
    padding: 28px;
    box-shadow: 
        0 40px 100px rgba(0, 0, 0, 0.35),
        0 12px 30px rgba(0, 0, 0, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    position: relative;
}

.device-frame.orientation-0 {
    padding: 28px 28px 72px;
}

.device-frame.orientation-90 {
    padding: 28px 72px 28px 28px;
}

.device-frame.orientation-180 {
    padding: 72px 28px 28px;
}

.device-frame.orientation-270 {
    padding: 28px 28px 28px 72px;
}

.device-frame.light-mode {
    background: linear-gradient(145deg, #e8e6e3, #d8d5cf);
    box-shadow: 
        0 40px 100px rgba(0, 0, 0, 0.15),
        0 12px 30px rgba(0, 0, 0, 0.08),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

.device-frame::before,
.device-frame::after {
    content: '';
    position: absolute;
    background: rgba(0, 0, 0, 0.4);
    border-radius: 6px;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.5);
}

.device-frame.light-mode::before,
.device-frame.light-mode::after {
    background: rgba(0, 0, 0, 0.15);
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.2);
}

.device-frame.orientation-0::before {
    bottom: 32px;
    left: 12%;
    width: 36%;
    height: 12px;
}

.device-frame.orientation-0::after {
    bottom: 32px;
    right: 12%;
    width: 36%;
    height: 12px;
}

.device-frame.orientation-90::before {
    right: 32px;
    top: 12%;
    width: 12px;
    height: 36%;
}

.device-frame.orientation-90::after {
    right: 32px;
    bottom: 12%;
    width: 12px;
    height: 36%;
}

.device-frame.orientation-180::before {
    top: 32px;
    left: 12%;
    width: 36%;
    height: 12px;
}

.device-frame.orientation-180::after {
    top: 32px;
    right: 12%;
    width: 36%;
    height: 12px;
}

.device-frame.orientation-270::before {
    left: 32px;
    top: 12%;
    width: 12px;
    height: 36%;
}

.device-frame.orientation-270::after {
    left: 32px;
    bottom: 12%;
    width: 12px;
    height: 36%;
}

.device-screen {
    background: #f7f4ee;
    border-radius: 12px;
    overflow: hidden;
    border: 2px solid rgba(0, 0, 0, 0.3);
    line-height: 0;
}

.device-frame.light-mode .device-screen {
    border-color: rgba(0, 0, 0, 0.15);
}

#previewCanvas {
    display: block;
    max-width: calc(100vw - var(--sidebar-width) - 200px);
    max-height: calc(100vh - 200px);
    width: auto;
    height: auto;
}

.empty-state {
    text-align: center;
    color: var(--color-text-muted);
}

.empty-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    color: var(--color-text-muted);
    opacity: 0.5;
}

.empty-state p {
    font-size: 15px;
    margin: 0;
}

.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(250, 249, 247, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    z-index: 100;
}

.loading-overlay.hidden {
    display: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-overlay span {
    font-size: 14px;
    color: var(--color-text-muted);
}

.device-toggle {
    position: absolute;
    bottom: 40px;
    right: 40px;
    width: 48px;
    height: 48px;
    border: 1px solid var(--color-border);
    border-radius: 12px;
    background: var(--color-surface);
    color: var(--color-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    z-index: 50;
}

.device-toggle:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(201, 168, 108, 0.2);
}

.device-toggle svg {
    width: 24px;
    height: 24px;
}

.sidebar::-webkit-scrollbar,
.file-list-items::-webkit-scrollbar,
.chapter-list::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track,
.file-list-items::-webkit-scrollbar-track,
.chapter-list::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb,
.file-list-items::-webkit-scrollbar-thumb,
.chapter-list::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover,
.file-list-items::-webkit-scrollbar-thumb:hover,
.chapter-list::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

.mb-3 {
    margin-bottom: 16px !important;
}

.g-3 {
    gap: 16px;
}

.row {
    display: flex;
    flex-wrap: wrap;
}

.col-6 {
    flex: 0 0 50%;
    max-width: 50%;
}

@media (max-width: 1200px) {
    :root {
        --sidebar-width: 360px;
    }
}