/* ===== 全局样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-dark: #1a1a2e;
    --bg-panel: #16213e;
    --bg-viewer: #2a2a3e;
    --bg-toolbar: #0f3460;
    --accent: #e94560;
    --accent-hover: #ff6b81;
    --text-light: #eee;
    --text-muted: #8899aa;
    --border-color: #2a3a5e;
    --btn-bg: #1a3a5e;
    --btn-hover: #2a4a6e;
    --primary: #3498db;
    --primary-hover: #2980b9;
    --danger: #e74c3c;
    --danger-hover: #c0392b;
}

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', Arial, sans-serif;
    background: var(--bg-viewer);
    color: var(--text-light);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    user-select: none;
}

/* ===== 顶部工具栏 ===== */
.toolbar {
    background: var(--bg-toolbar);
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.3);
    z-index: 100;
    flex-shrink: 0;
}

.toolbar-left, .toolbar-center, .toolbar-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.file-upload-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--accent);
    color: white;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
}

.file-upload-btn:hover {
    background: var(--accent-hover);
}

.file-name {
    font-size: 13px;
    color: var(--text-muted);
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.page-info {
    font-size: 13px;
    color: var(--text-light);
    display: flex;
    align-items: center;
    gap: 4px;
}

#pageInput {
    width: 42px;
    background: var(--btn-bg);
    border: 1px solid var(--border-color);
    color: var(--text-light);
    border-radius: 4px;
    padding: 2px 4px;
    text-align: center;
    font-size: 13px;
}

#pageInput::-webkit-inner-spin-button {
    opacity: 0;
}

.zoom-level {
    font-size: 13px;
    min-width: 48px;
    text-align: center;
}

.divider {
    width: 1px;
    height: 24px;
    background: var(--border-color);
    margin: 0 4px;
}

.tool-btn {
    background: var(--btn-bg);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    white-space: nowrap;
}

.tool-btn:hover {
    background: var(--btn-hover);
}

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

.tool-btn.primary {
    background: var(--primary);
    border-color: var(--primary);
}

.tool-btn.primary:hover {
    background: var(--primary-hover);
}

.tool-btn.danger {
    background: transparent;
    border-color: var(--danger);
    color: var(--danger);
}

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

/* ===== 主体布局：侧边栏 + 查看区 水平排列 ===== */
.main-content {
    flex: 1;
    display: flex;
    overflow: hidden;
}

/* ===== 左侧工具面板 ===== */
.side-panel {
    width: 240px;
    background: var(--bg-panel);
    overflow-y: auto;
    flex-shrink: 0;
    border-right: 1px solid var(--border-color);
}

.side-panel::-webkit-scrollbar {
    width: 6px;
}

.side-panel::-webkit-scrollbar-track {
    background: var(--bg-panel);
}

.side-panel::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.tool-section {
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
}

.tool-section h3 {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 10px;
}

.tool-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
}

.tool-select {
    background: var(--btn-bg);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    padding: 10px 6px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    transition: all 0.2s;
}

.tool-select:hover {
    background: var(--btn-hover);
}

.tool-select.active {
    background: var(--accent);
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(233,69,96,0.3);
}

.tool-select span {
    font-size: 11px;
}

/* ===== 颜色选择器 ===== */
.color-picker-row {
    display: flex;
    align-items: center;
    gap: 8px;
}

.color-swatches {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    flex: 1;
}

.color-swatch {
    width: 100%;
    aspect-ratio: 1;
    border-radius: 6px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform 0.15s, border-color 0.15s;
}

.color-swatch:hover {
    transform: scale(1.1);
}

.color-swatch.active {
    border-color: var(--text-light);
    transform: scale(1.1);
}

#customColor {
    width: 36px;
    height: 36px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    background: none;
}

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

.slider-row input[type="range"] {
    flex: 1;
    accent-color: var(--accent);
    cursor: pointer;
}

.slider-value {
    font-size: 12px;
    color: var(--text-muted);
    min-width: 40px;
    text-align: right;
}

/* ===== 文字设置 ===== */
.tool-section label {
    font-size: 12px;
    color: var(--text-muted);
    display: block;
    margin-bottom: 4px;
    margin-top: 8px;
}

.tool-section select {
    width: 100%;
    background: var(--btn-bg);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 6px 8px;
    font-size: 13px;
    cursor: pointer;
}

.text-style-buttons {
    display: flex;
    gap: 6px;
    margin-top: 8px;
}

.style-btn {
    background: var(--btn-bg);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    width: 36px;
    height: 36px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
}

.style-btn:hover {
    background: var(--btn-hover);
}

.style-btn.active {
    background: var(--accent);
    border-color: var(--accent);
}

/* ===== PDF显示区 ===== */
.viewer-container {
    flex: 1;
    overflow: auto;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 24px;
    background: var(--bg-viewer);
    position: relative;
    min-width: 0;
}

.viewer-container::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.viewer-container::-webkit-scrollbar-track {
    background: var(--bg-viewer);
}

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

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--text-muted);
    margin: auto;
}

.empty-icon {
    font-size: 64px;
    margin-bottom: 16px;
}

.empty-state h1 {
    color: var(--text-light);
    margin-bottom: 8px;
    font-size: 22px;
    font-weight: 600;
}

.empty-state p {
    line-height: 1.6;
    font-size: 14px;
}

.features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 24px;
}

.feature-item {
    background: var(--bg-panel);
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 13px;
    color: var(--text-light);
    border: 1px solid var(--border-color);
}

.pdf-viewer {
    position: relative;
    box-shadow: 0 4px 20px rgba(0,0,0,0.4);
    flex-shrink: 0;
}

#pdfCanvas {
    display: block;
    background: white;
}

.annotation-layer {
    position: absolute;
    top: 0;
    left: 0;
    cursor: default;
}

/* PDF.js TextLayer - 用于文字选择高亮 */
.textLayer {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 10;
    overflow: hidden;
}

.textLayer span[role="presentation"] {
    position: absolute;
    white-space: pre;
    line-height: 1.0;
    margin: 0;
    padding: 0;
    border: none;
    outline: none;
}

/* ===== 文字输入弹窗 ===== */
.text-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
}

.text-modal-content {
    background: var(--bg-panel);
    padding: 24px;
    border-radius: 12px;
    width: 400px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.5);
}

.text-modal-content h3 {
    margin-bottom: 12px;
    color: var(--text-light);
}

#textInputArea {
    width: 100%;
    background: var(--btn-bg);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 10px;
    font-size: 14px;
    resize: vertical;
    font-family: inherit;
}

#textInputArea:focus {
    outline: none;
    border-color: var(--accent);
}

.text-modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
    margin-top: 12px;
}

/* ===== 加载遮罩 ===== */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 300;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-bottom: 16px;
}

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

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

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-panel);
    color: var(--text-light);
    padding: 12px 24px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 16px rgba(0,0,0,0.4);
    z-index: 400;
    font-size: 14px;
    animation: toastIn 0.3s ease;
}

@keyframes toastIn {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .side-panel {
        width: 180px;
    }

    .toolbar {
        flex-wrap: wrap;
        height: auto;
        padding: 8px;
        gap: 8px;
    }

    .toolbar-left, .toolbar-center, .toolbar-right {
        flex-wrap: wrap;
    }

    .file-name {
        display: none;
    }
}