/* ====================
   全局样式 - 黑白风格（有层次感）
   ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: #f5f5f5;
    color: #1a1a1a;
    height: 100vh;
    overflow: hidden;
}

/* ====================
   主容器布局 - 四栏
   ==================== */
.app-container {
    display: flex;
    height: 100vh;
    background: #e8e8e8;
    overflow: hidden;
}

/* ====================
   左侧：项目列表
   ==================== */
.project-sidebar {
    width: 280px;
    background: #ffffff;
    border-right: 1px solid #d0d0d0;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.project-sidebar.collapsed {
    width: 70px !important;
    min-width: 70px;
}

.project-sidebar.collapsed .search-box,
.project-sidebar.collapsed .project-filters,
.project-sidebar.collapsed .sidebar-footer,
.project-sidebar.collapsed .new-project-btn {
    display: none;
}

.project-sidebar.collapsed .sidebar-content {
    padding: 0;
}

.project-sidebar.collapsed .project-list {
    padding: 10px 5px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.project-sidebar.collapsed .project-item {
    width: 60px;
    height: 60px;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 8px;
    border: 2px solid #e0e0e0;
    background: #ffffff;
    cursor: pointer;
    transition: all 0.2s;
}

.project-sidebar.collapsed .project-item:hover {
    border-color: #1a1a1a;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.project-sidebar.collapsed .project-item.active {
    background: #1a1a1a;
}

.project-sidebar.collapsed .project-item.active .project-name {
    color: #ffffff;
}

.project-sidebar.collapsed .project-name {
    font-size: 24px;
    font-weight: bold;
    color: #1a1a1a;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-sidebar.collapsed .project-meta {
    display: none;
}

.sidebar-toggle {
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #666666;
    flex-shrink: 0;
    border-radius: 4px;
}

.sidebar-toggle:hover {
    background: rgba(0, 0, 0, 0.05);
    color: #1a1a1a;
}

.project-sidebar.collapsed .sidebar-toggle {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    top: 10px;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid #e0e0e0;
    background: linear-gradient(to bottom, #fafafa, #f5f5f5);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    flex-shrink: 0;
}

.project-sidebar.collapsed .sidebar-header {
    justify-content: center;
    padding: 50px 10px 15px 10px;
    position: relative;
}

.project-sidebar.collapsed .logo-section {
    width: 100%;
    justify-content: center;
}

.project-sidebar.collapsed .logo-text {
    display: none;
}

.project-sidebar.collapsed .logo-icon {
    font-size: 28px;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
    min-width: 0;
}

.logo-icon {
    font-size: 36px;
    filter: grayscale(100%);
}

.logo-text h1 {
    font-size: 18px;
    font-weight: 600;
    color: #1a1a1a;
    letter-spacing: -0.5px;
}

.logo-text p {
    font-size: 12px;
    color: #666666;
    margin-top: 2px;
}

.sidebar-content {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    background: #fafafa;
}

.new-project-btn {
    width: 100%;
    padding: 12px;
    background: linear-gradient(to bottom, #2a2a2a, #1a1a1a);
    color: #ffffff;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    margin-bottom: 20px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.new-project-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.new-project-btn:active {
    transform: translateY(0);
}

.search-box {
    margin-bottom: 15px;
}

.search-box input {
    width: 100%;
    padding: 10px 12px;
    background: #ffffff;
    border: 1px solid #d0d0d0;
    border-radius: 6px;
    color: #1a1a1a;
    font-size: 13px;
    transition: all 0.2s;
}

.search-box input:focus {
    outline: none;
    border-color: #999999;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.search-box input::placeholder {
    color: #999999;
}

.project-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.filter-btn {
    padding: 6px 12px;
    background: #ffffff;
    border: 1px solid #d0d0d0;
    border-radius: 20px;
    color: #666666;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.filter-btn:hover {
    background: #f0f0f0;
    border-color: #999999;
}

.filter-btn.active {
    background: #1a1a1a;
    color: #ffffff;
    border-color: #1a1a1a;
}

.project-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.project-item {
    padding: 14px;
    background: #ffffff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    transition: all 0.2s;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    position: relative;
}

.project-item:hover {
    background: #f8f8f8;
    border-color: #999999;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transform: translateX(2px);
}

.project-item.active {
    background: #f0f0f0;
    border-color: #1a1a1a;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
}

.project-content {
    flex: 1;
    cursor: pointer;
    min-width: 0;
}

.project-name {
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 4px;
    color: #1a1a1a;
}

.project-meta {
    display: flex;
    justify-content: space-between;
    font-size: 11px;
    color: #999999;
}

.project-delete-btn {
    background: none;
    border: none;
    font-size: 18px;
    cursor: pointer;
    padding: 6px 8px;
    border-radius: 4px;
    transition: all 0.2s;
    opacity: 0;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-item:hover .project-delete-btn {
    opacity: 1;
}

.project-delete-btn:hover {
    background: #fee;
    transform: scale(1.1);
}

.project-delete-btn:active {
    transform: scale(0.95);
}

.sidebar-footer {
    padding: 15px 20px;
    border-top: 1px solid #e0e0e0;
    background: #ffffff;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.avatar {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #2a2a2a, #1a1a1a);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: #ffffff;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.username {
    font-weight: 600;
    font-size: 13px;
    color: #1a1a1a;
}

.user-role {
    font-size: 11px;
    color: #999999;
}

/* ====================
   中间：章节大纲
   ==================== */
.outline-panel {
    width: 320px;
    min-width: 200px;
    max-width: 600px;
    background: #ffffff;
    border-right: 1px solid #d0d0d0;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    overflow: hidden;
}

.outline-panel.hidden {
    display: none;
}

.outline-header {
    padding: 16px 20px;
    border-bottom: 1px solid #e8e8e8;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #ffffff;
    min-height: 64px;
    gap: 12px;
}

.outline-header h2 {
    font-size: 16px;
    font-weight: 600;
    color: #1a1a1a;
    flex: 1;
}

.refresh-project-btn {
    padding: 8px 12px;
    background: #f5f5f5;
    border: 1px solid #e0e0e0;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.refresh-project-btn:hover {
    background: #e8e8e8;
    border-color: #d0d0d0;
}

.refresh-project-btn:active {
    background: #d8d8d8;
}

.refresh-project-btn.refreshing {
    animation: spin 1s linear infinite;
    pointer-events: none;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.outline-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.btn-save {
    padding: 7px 16px;
    background: #1a1a1a;
    color: #ffffff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-save:hover {
    background: #333333;
}

.progress-bar {
    position: relative;
    width: 80px;
    height: 20px;
    background: rgba(0, 0, 0, 0.06);
    border-radius: 10px;
    overflow: hidden;
}

.progress-fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    background: #1a1a1a;
    transition: width 0.3s;
    border-radius: 10px;
}

.progress-text {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 10px;
    font-weight: 500;
    color: #ffffff;
    z-index: 1;
}

.outline-content {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    background: #ffffff;
}

/* ====================
   优雅的文件树结构
   ==================== */
.tree-root {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 13px;
    user-select: none;
    padding: 0;
}

.tree-node {
    margin: 0;
}

/* 通用节点样式 */
.tree-item {
    display: flex;
    align-items: center;
    height: 32px;
    padding: 0 12px 0 0;
    cursor: pointer;
    line-height: 32px;
    white-space: nowrap;
    margin: 1px 4px;
    gap: 0;
    background: transparent;
    border-radius: 6px;
    transition: all 0.15s ease;
}

.tree-item:hover {
    background: rgba(0, 0, 0, 0.03);
}

/* 文件夹节点 */
.tree-item.folder {
    font-weight: 500;
    color: #1a1a1a;
}

.tree-item.folder:hover {
    background: linear-gradient(90deg, rgba(0, 120, 212, 0.06), transparent);
}

/* 文件节点 */
.tree-item.file {
    font-weight: 400;
    color: #333333;
}

.tree-item.file:hover {
    background: rgba(0, 0, 0, 0.04);
}

/* 激活状态 */
.tree-item.active {
    background: rgba(0, 120, 212, 0.08);
}

/* 选中状态 */
.tree-item.selected {
    background: #0078d4 !important;
    color: #ffffff !important;
}

.tree-item.selected .tree-toggle,
.tree-item.selected .tree-icon,
.tree-item.selected .tree-label,
.tree-item.selected .tree-count {
    color: #ffffff !important;
}

/* 预览模式（单击打开）*/
.tree-item.preview {
    background: rgba(0, 120, 212, 0.04);
    border-left: 2px solid rgba(0, 120, 212, 0.3);
}

.tree-item.preview .tree-label {
    font-style: italic;
    opacity: 0.9;
}

/* 箭头切换 */
.tree-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 16px;
    height: 16px;
    margin: 0 4px 0 0;
    font-size: 9px;
    color: #888888;
    flex-shrink: 0;
    transition: transform 0.15s ease;
}

.tree-toggle::before {
    content: '▶';
    display: block;
    transition: transform 0.15s ease;
}

.tree-toggle.expanded::before {
    transform: rotate(90deg);
}

.tree-toggle:hover {
    color: #0078d4;
}

.tree-spacer {
    width: 16px;
    flex-shrink: 0;
}

/* 图标 */
.tree-icon {
    width: 16px;
    height: 16px;
    margin-right: 8px;
    font-size: 14px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 标签 */
.tree-label {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 13px;
    color: #2c2c2c;
}

/* 计数 */
.tree-count {
    margin-left: 8px;
    padding: 2px 6px;
    font-size: 11px;
    color: #888888;
    background: transparent;
    font-weight: 400;
}

/* 子节点容器 */
.tree-children {
    display: none;
}

.tree-children.expanded {
    display: block;
}

/* 空文件夹提示 */
.tree-empty {
    height: 28px;
    line-height: 28px;
    padding-left: 52px;
    color: #999999;
    font-size: 12px;
    font-style: italic;
    opacity: 0.7;
}

/* 层级缩进 - 优化间距（每层 18px）*/
.tree-item[data-depth="0"] { padding-left: 12px; }
.tree-item[data-depth="1"] { padding-left: 30px; }
.tree-item[data-depth="2"] { padding-left: 48px; }
.tree-item[data-depth="3"] { padding-left: 66px; }
.tree-item[data-depth="4"] { padding-left: 84px; }

/* 项目根节点 - 优雅样式 */
.tree-root-item {
    font-weight: 600;
    color: #1a1a1a;
    background: rgba(0, 120, 212, 0.04);
    border-left: 3px solid #0078d4;
    padding: 10px 12px !important;
    margin: 0 4px 12px 4px;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.tree-root-item:hover {
    background: rgba(0, 120, 212, 0.08);
    border-left-color: #0086f0;
}

.chapter-tree {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.chapter-item {
    padding: 12px;
    background: #ffffff;
    border: 1px solid #e0e0e0;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 13px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.chapter-item:hover {
    background: #f8f8f8;
    border-color: #999999;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
    transform: translateX(2px);
}

.chapter-item.active {
    background: #f0f0f0;
    border-color: #1a1a1a;
    font-weight: 600;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
}

/* ====================
   右侧：编辑器面板
   ==================== */
.editor-panel {
    flex: 1;
    background: #ffffff;
    display: flex;
    flex-direction: column;
    border-right: 1px solid #d0d0d0;
    overflow: hidden;
    min-width: 0;
    position: relative; /* 为缺省页的绝对定位提供参照 */
}

.editor-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid #e0e0e0;
    background: linear-gradient(to bottom, #fafafa, #f5f5f5);
    height: 80px;
}

.chapter-tabs {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    flex: 1;
}

.chapter-tab {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: #ffffff;
    border: 1px solid #d0d0d0;
    border-radius: 6px;
    font-size: 13px;
    white-space: nowrap;
    transition: all 0.2s;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.chapter-tab > span:first-child {
    cursor: pointer;
}

.chapter-tab .tab-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    border-radius: 3px;
    font-size: 16px;
    line-height: 1;
    cursor: pointer;
    opacity: 0.6;
    transition: all 0.15s;
}

.chapter-tab .tab-close:hover {
    opacity: 1;
    background: rgba(0, 0, 0, 0.1);
}

.chapter-tab:hover {
    background: #f8f8f8;
    border-color: #999999;
}

.chapter-tab.active {
    background: #1a1a1a;
    color: #ffffff;
    border-color: #1a1a1a;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
}

.chapter-tab.active .tab-close:hover {
    background: rgba(255, 255, 255, 0.2);
}

.editor-actions {
    display: flex;
    gap: 10px;
}

.btn-new-chapter {
    padding: 6px 12px;
    background: #ffffff;
    border: 1px solid #1a1a1a;
    color: #1a1a1a;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
}

.btn-new-chapter:hover {
    background: #1a1a1a;
    color: #ffffff;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.btn-save-chapter {
    padding: 6px 16px;
    background: #1a1a1a;
    color: #ffffff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.btn-save-chapter:hover {
    background: #2a2a2a;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.15);
}

.editor-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: #fafafa;
}

.chapter-title-editor {
    padding: 5px 20px;
    border-bottom: 1px solid #e0e0e0;
    background: #ffffff;
}

.chapter-title-editor input {
    width: 100%;
    padding: 10px 0;
    border: none;
    font-size: 20px;
    font-weight: 600;
    outline: none;
    color: #1a1a1a;
    background: transparent;
}

#chapterContentEditor {
    flex: 1;
    padding: 20px;
    border: none;
    outline: none;
    font-size: 15px;
    line-height: 1.8;
    resize: none;
    font-family: inherit;
    color: #1a1a1a;
    background: #fafafa;
    transition: all 0.3s;
}

#chapterContentEditor:disabled {
    background: #f5f5f5;
    color: #666666;
    cursor: not-allowed;
}

#chapterTitleInput:disabled {
    background: #f5f5f5;
    color: #666666;
    cursor: not-allowed;
}

/* 拖拽样式 */
.tree-item.dragging {
    opacity: 0.5;
    background: rgba(0, 120, 212, 0.1);
}

.tree-item[draggable="true"] {
    cursor: grab;
}

.tree-item[draggable="true"]:active {
    cursor: grabbing;
}

.editor-footer {
    padding: 12px 20px;
    border-top: 1px solid #e0e0e0;
    background: linear-gradient(to bottom, #fafafa, #ffffff);
}

/* 编辑器缺省页 */
.editor-empty-state {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #ffffff;
    z-index: 1;
}

.editor-empty-state.hidden {
    display: none;
}

.empty-state-content {
    text-align: center;
    max-width: 500px;
    padding: 40px;
}

.empty-state-icon {
    font-size: 80px;
    margin-bottom: 20px;
    opacity: 0.8;
}

.empty-state-title {
    font-size: 24px;
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 12px;
}

.empty-state-description {
    font-size: 16px;
    color: #666;
    margin-bottom: 30px;
    line-height: 1.6;
}

.empty-state-tips {
    background: #f8f9fa;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 20px;
    text-align: left;
}

.empty-state-tips p {
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 12px;
}

.empty-state-tips ul {
    list-style: none;
    padding: 0;
}

.empty-state-tips li {
    padding: 6px 0;
    color: #666;
    font-size: 14px;
    line-height: 1.6;
}

.empty-state-tips li::before {
    content: "•";
    color: #1a1a1a;
    font-weight: bold;
    display: inline-block;
    width: 1em;
    margin-left: -1em;
    margin-right: 0.5em;
}

/* Diff 预览区域 */
.diff-preview {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: #ffffff;
    display: flex;
    flex-direction: column;
    z-index: 10;
    overflow: hidden;
}

.diff-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 2px solid #e0e0e0;
    background: linear-gradient(to bottom, #fafafa, #f5f5f5);
}

.diff-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 600;
    color: #1a1a1a;
}

.diff-icon {
    font-size: 20px;
}

.diff-actions {
    display: flex;
    gap: 12px;
}

.btn-accept {
    background: #52c41a;
    color: #ffffff;
    border: none;
    padding: 8px 20px;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-accept:hover {
    background: #3ba00f;
    box-shadow: 0 2px 8px rgba(82, 196, 26, 0.3);
}

.btn-reject {
    background: #ff4d4f;
    color: #ffffff;
    border: none;
    padding: 8px 20px;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-reject:hover {
    background: #d9363e;
    box-shadow: 0 2px 8px rgba(255, 77, 79, 0.3);
}

.diff-revision-note {
    padding: 12px 20px;
    background: #fff7e6;
    border-bottom: 1px solid #ffd591;
    font-size: 14px;
    color: #ad6800;
}

.diff-revision-note strong {
    font-weight: 600;
    margin-right: 8px;
}

.diff-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: #fafafa;
}

/* diff2html 样式覆盖 */
.diff-content .d2h-wrapper {
    border: 1px solid #e0e0e0;
    border-radius: 4px;
    overflow: hidden;
}

.diff-content .d2h-file-header {
    background: #f5f5f5;
    border-bottom: 1px solid #e0e0e0;
    padding: 10px 15px;
}

.diff-content .d2h-code-line {
    font-size: 13px;
    line-height: 1.6;
}

.diff-content .d2h-ins {
    background: #f0f9ff;
    border-left: 3px solid #52c41a;
}

.diff-content .d2h-del {
    background: #fff2f0;
    border-left: 3px solid #ff4d4f;
}

/* 内容统计 */
.content-stats {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    gap: 24px;
    padding-left: 4px;
}

.stat-item {
    display: flex;
    align-items: baseline;
    gap: 6px;
}

.stat-label {
    font-size: 12px;
    color: #666666;
    font-weight: 400;
}

.stat-value {
    font-size: 13px;
    font-weight: 600;
    color: #1a1a1a;
}

.stat-divider {
    width: 1px;
    height: 14px;
    background: #d0d0d0;
    align-self: center;
}

/* ====================
   可拖动分隔条
   ==================== */
.resizer {
    width: 4px;
    background: transparent;
    cursor: col-resize;
    flex-shrink: 0;
    position: relative;
    transition: background 0.2s;
}

.resizer:hover {
    background: #0078d4;
}

.resizer::before {
    content: '';
    position: absolute;
    left: -2px;
    top: 0;
    bottom: 0;
    width: 8px;
    background: transparent;
}

.resizer.resizing {
    background: #0078d4;
}

/* ====================
   最右侧：AI助手面板
   ==================== */
.ai-assistant-panel {
    width: 400px;
    min-width: 300px;
    max-width: 800px;
    background: #ffffff;
    border-left: 1px solid #d0d0d0;
    display: flex;
    flex-direction: column;
    box-shadow: -2px 0 8px rgba(0, 0, 0, 0.05);
    flex-shrink: 0;
    min-height: 0;
}

.chat-header {
    padding: 20px;
    border-bottom: 1px solid #e0e0e0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(to bottom, #fafafa, #f5f5f5);
    flex-shrink: 0;
    height: 80px;
}

.chat-header h2 {
    font-size: 18px;
    color: #1a1a1a;
    font-weight: 600;
}

.chat-header-actions {
    display: flex;
    gap: 10px;
}

/* 工具栏 */
.chat-toolbar {
    padding: 12px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #e8e8e8;
    margin-bottom: 12px;
}

.toolbar-left {
    display: flex;
    gap: 10px;
    align-items: center;
}

.toolbar-right {
    display: flex;
    align-items: center;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: #fafafa;
    min-height: 0; /* 确保flex子元素可以正确收缩 */
}

.welcome-message {
    max-width: 600px;
    margin: 50px auto;
    text-align: center;
}

.welcome-message h2 {
    margin-bottom: 15px;
    color: #1a1a1a;
    font-weight: 600;
}

.welcome-message p {
    margin-bottom: 30px;
    color: #666666;
}

.examples {
    background: #ffffff;
    padding: 20px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    text-align: left;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.examples h3 {
    margin-bottom: 10px;
    font-size: 14px;
    color: #1a1a1a;
    font-weight: 600;
}

.examples ul {
    list-style: none;
}

.examples li {
    padding: 10px 0;
    border-bottom: 1px solid #f0f0f0;
    color: #666666;
    font-size: 13px;
}

.examples li:last-child {
    border-bottom: none;
}

/* 消息气泡 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message {
    margin-bottom: 20px;
    animation: fadeIn 0.3s;
}

.message-user,
.message-assistant {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
}

.message-role {
    font-size: 12px;
    color: #666666;
    margin-bottom: 6px;
    margin-left: 4px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.message-content {
    max-width: 100%;
    padding: 16px 20px;
    border-radius: 12px;
    line-height: 1.8;
    position: relative;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.message-user .message-content {
    background: linear-gradient(135deg, #2a2a2a, #1a1a1a);
    color: #ffffff;
}

.message-user .message-content::before {
    content: '';
    position: absolute;
    left: 20px;
    top: -8px;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 0 8px 8px 8px;
    border-color: transparent transparent #2a2a2a transparent;
}

.message-assistant .message-content {
    background: #ffffff;
    color: #1a1a1a;
    border: 1px solid #e0e0e0;
}

/* AI助手气泡箭头 - 外层描边 */
.message-assistant .message-content::before {
    content: '';
    position: absolute;
    left: 20px;
    top: -9px;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 0 8px 9px 8px;
    border-color: transparent transparent #e0e0e0 transparent;
}

/* AI助手气泡箭头 - 内层白色 */
.message-assistant .message-content::after {
    content: '';
    position: absolute;
    left: 20px;
    top: -8px;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 0 8px 8px 8px;
    border-color: transparent transparent #ffffff transparent;
}

.message-content h1,
.message-content h2,
.message-content h3 {
    margin: 15px 0 10px 0;
    color: inherit;
}

.message-content h1:first-child,
.message-content h2:first-child,
.message-content h3:first-child {
    margin-top: 0;
}

.message-content ul,
.message-content ol {
    margin: 10px 0;
    padding-left: 20px;
}

.message-content p {
    margin: 10px 0;
}

.message-content code {
    background: rgba(0, 0, 0, 0.05);
    padding: 3px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.message-user .message-content code {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.2);
}

.message-content pre {
    background: #f5f5f5;
    padding: 16px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 12px 0;
    border: 1px solid #e0e0e0;
}

.message-user .message-content pre {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

.message-content pre code {
    background: none;
    padding: 0;
    border: none;
}

/* 输入区域 */
.chat-input-container {
    padding: 16px 20px 20px 20px;
    border-top: 1px solid #e0e0e0;
    display: flex;
    flex-direction: column;
    background: #ffffff;
}

.file-reference-area {
    background: #f5f5f5;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 12px;
}

.reference-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    font-size: 13px;
    font-weight: 500;
    color: #1a1a1a;
}

.btn-text {
    background: none;
    border: none;
    color: #666666;
    font-size: 12px;
    cursor: pointer;
    padding: 2px 8px;
    text-decoration: underline;
}

.btn-text:hover {
    color: #1a1a1a;
}

.reference-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.reference-item {
    display: flex;
    align-items: center;
    gap: 6px;
    background: #ffffff;
    border: 1px solid #d0d0d0;
    border-radius: 6px;
    padding: 6px 10px;
    font-size: 12px;
    color: #1a1a1a;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.reference-item-remove {
    background: none;
    border: none;
    color: #999999;
    cursor: pointer;
    font-size: 14px;
    padding: 0;
    margin-left: 4px;
    line-height: 1;
}

.reference-item-remove:hover {
    color: #1a1a1a;
}

.btn-file-action {
    padding: 8px 16px;
    font-size: 13px;
    border: 1px solid #d0d0d0;
    background: #ffffff;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    color: #666666;
    font-weight: 500;
}

.btn-file-action:hover {
    background: #f5f5f5;
    border-color: #999999;
}

/* @ 文件选择下拉菜单 */
.at-file-dropdown {
    position: absolute;
    bottom: calc(100% + 5px);
    left: 0;
    right: 0;
    max-height: 500px;
    background: #ffffff;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.at-file-search {
    padding: 10px;
    border-bottom: 1px solid #e0e0e0;
    background: #fafafa;
}

.at-file-search input {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid #d0d0d0;
    border-radius: 6px;
    font-size: 13px;
    outline: none;
}

.at-file-search input:focus {
    border-color: #999999;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.at-file-list {
    flex: 1;
    overflow-y: auto;
    max-height: 400px;
}

.at-file-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    cursor: pointer;
    transition: all 0.15s;
    font-size: 13px;
}

.at-file-item:hover {
    background: #f5f5f5;
}

.at-file-item.selected {
    background: #1a1a1a;
    color: #ffffff;
}

.at-file-hint {
    display: flex;
    gap: 15px;
    padding: 8px 12px;
    background: #f5f5f5;
    border-top: 1px solid #e0e0e0;
    font-size: 11px;
    color: #999999;
}

.input-group {
    display: flex;
    flex-direction: column;
}

#chatInput {
    width: 100%;
    padding: 12px;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    resize: none;
    font-size: 14px;
    font-family: inherit;
    transition: all 0.2s;
    min-height: 80px;
}

#chatInput:focus {
    outline: none;
    border-color: #0078d4;
    box-shadow: 0 0 0 3px rgba(0, 120, 212, 0.1);
}

/* 按钮通用样式 */
.btn {
    padding: 8px 16px;
    border: 1px solid #d0d0d0;
    background: #ffffff;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
    color: #1a1a1a;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.btn:hover {
    background: #f5f5f5;
    border-color: #999999;
}

.btn-primary {
    padding: 10px 24px;
    border-radius: 8px;
    background: linear-gradient(to bottom, #2a2a2a, #1a1a1a);
    color: #ffffff;
    border: none;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
    background: linear-gradient(to bottom, #3a3a3a, #2a2a2a);
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.15);
}

.btn-small {
    padding: 6px 12px;
    font-size: 12px;
}

/* Loading 状态 */
.loading-indicator {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    background: #f5f5f5;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    margin-bottom: 16px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.loading-spinner {
    width: 20px;
    height: 20px;
    border: 3px solid #e0e0e0;
    border-top-color: #1a1a1a;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-text {
    color: #666666;
    font-size: 14px;
}

/* 推理过程 */
.thinking-process {
    margin-top: 12px;
    padding: 12px 16px;
    background: #f5f5f5;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    font-size: 12px;
    max-height: 300px;
    overflow-y: auto;
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: 'Courier New', monospace;
    line-height: 1.6;
}

.thinking-toggle {
    cursor: pointer;
    color: inherit;
    font-size: 13px;
    margin-top: 10px;
    display: inline-block;
    padding: 6px 12px;
    background: #f5f5f5;
    border: 1px solid #d0d0d0;
    border-radius: 6px;
    transition: all 0.2s;
}

.thinking-toggle:hover {
    background: #1a1a1a;
    color: #ffffff;
    border-color: #1a1a1a;
}

/* ====================
   模态框
   ==================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: #ffffff;
    padding: 30px;
    border: 1px solid #d0d0d0;
    border-radius: 12px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.modal-content h2 {
    margin-bottom: 20px;
    font-size: 20px;
    color: #1a1a1a;
}

.modal-content input,
.modal-content textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    font-size: 14px;
    margin-bottom: 15px;
    font-family: inherit;
    transition: all 0.2s;
}

.modal-content input:focus,
.modal-content textarea:focus {
    outline: none;
    border-color: #999999;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.btn-secondary {
    padding: 10px 24px;
    background: #ffffff;
    color: #1a1a1a;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
}

.btn-secondary:hover {
    background: #f5f5f5;
    border-color: #999999;
}

.modal-large {
    max-width: 800px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.btn-close {
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #666666;
    transition: all 0.2s;
}

.btn-close:hover {
    color: #1a1a1a;
}

.prompt-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 1px solid #e0e0e0;
}

.prompt-tab {
    padding: 10px 20px;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    cursor: pointer;
    font-size: 14px;
    color: #999999;
    transition: all 0.2s;
}

.prompt-tab:hover {
    color: #1a1a1a;
}

.prompt-tab.active {
    color: #1a1a1a;
    border-bottom-color: #1a1a1a;
    font-weight: 600;
}

.prompt-tab-content {
    display: none;
}

.prompt-tab-content.active {
    display: block;
}

.prompt-info {
    padding: 12px 15px;
    background: #fff7e6;
    border: 1px solid #ffd591;
    border-left: 4px solid #faad14;
    border-radius: 6px;
    margin-bottom: 15px;
    font-size: 13px;
    color: #ad6800;
    line-height: 1.6;
}

.prompt-info p {
    margin: 4px 0;
}

.prompt-info strong {
    color: #d48806;
    font-weight: 600;
    font-family: 'Consolas', 'Monaco', monospace;
    background: #fff;
    padding: 2px 6px;
    border-radius: 3px;
}

/* Settings 标签页样式 */
.settings-tabs {
    display: flex;
    border-bottom: 2px solid #e0e0e0;
    margin-bottom: 20px;
    gap: 5px;
}

.settings-tab {
    padding: 12px 24px;
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: #666;
    transition: all 0.2s;
}

.settings-tab:hover {
    color: #1a1a1a;
    background: #f5f5f5;
}

.settings-tab.active {
    color: #1a1a1a;
    border-bottom-color: #1a1a1a;
    font-weight: 600;
}

.settings-tab-content {
    position: relative;
}

.settings-panel {
    display: none;
}

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

/* API配置表单 */
.api-config-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 13px;
    font-weight: 600;
    color: #1a1a1a;
}

.form-group .required {
    color: #ff4d4f;
    margin-left: 2px;
}

.input-with-button {
    position: relative;
    display: flex;
    align-items: center;
    width: 100%;
}

.input-with-button .form-input {
    flex: 1;
    padding-right: 50px;
}

.toggle-visibility-btn {
    position: absolute;
    right: 4px;
    top: 38%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px 12px;
    border-radius: 4px;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 32px;
    z-index: 1;
}

.toggle-visibility-btn:hover {
    background: #f0f0f0;
}

.toggle-visibility-btn:active {
    background: #e0e0e0;
}

.toggle-visibility-btn .eye-icon {
    font-size: 18px;
    user-select: none;
    line-height: 1;
}

.form-input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #d0d0d0;
    border-radius: 4px;
    font-size: 14px;
    font-family: 'Consolas', 'Monaco', monospace;
    transition: all 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: #1a1a1a;
    box-shadow: 0 0 0 2px rgba(26, 26, 26, 0.1);
}

.form-input::placeholder {
    color: #999;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', sans-serif;
}

.form-hint {
    font-size: 12px;
    color: #999;
    line-height: 1.4;
}

.btn-secondary {
    background: #ffffff;
    color: #1a1a1a;
    border: 1px solid #d0d0d0;
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-secondary:hover {
    background: #f5f5f5;
    border-color: #1a1a1a;
}

.prompt-editor {
    width: 100%;
    min-height: 400px;
    padding: 15px;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 13px;
    resize: vertical;
    margin-bottom: 15px;
    transition: all 0.2s;
}

.prompt-editor:focus {
    outline: none;
    border-color: #999999;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

/* ====================
   滚动条
   ==================== */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: #f5f5f5;
}

::-webkit-scrollbar-thumb {
    background: #c0c0c0;
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a0a0a0;
}

/* ====================
   右键菜单
   ==================== */
.context-menu {
    position: fixed;
    background: #ffffff;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    padding: 6px 0;
    z-index: 10000;
    min-width: 180px;
}

.context-menu-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 13px;
    color: #1a1a1a;
}

.context-menu-item:hover {
    background: #f5f5f5;
}

.context-menu-item.context-menu-danger {
    color: #ff4d4f;
}

.context-menu-item.context-menu-danger:hover {
    background: #fff1f0;
}

.context-menu-icon,
.context-icon {
    font-size: 16px;
    width: 20px;
    text-align: center;
    flex-shrink: 0;
}

.context-menu-divider {
    height: 1px;
    background: #e0e0e0;
    margin: 6px 0;
}

.modal-small {
    max-width: 400px;
}

.modal-input {
    width: 100%;
    padding: 12px;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    font-size: 14px;
    margin-bottom: 15px;
    font-family: inherit;
    transition: all 0.2s;
}

.modal-input:focus {
    outline: none;
    border-color: #999999;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

/* ====================
   响应式设计
   ==================== */
@media screen and (max-width: 1400px) {
    .app-container {
        grid-template-columns: 260px 300px 1fr 380px;
    }
}

@media screen and (max-width: 1200px) {
    .app-container {
        grid-template-columns: 240px 280px 1fr 360px;
    }
}

@media screen and (max-width: 768px) {
    .app-container {
        grid-template-columns: 1fr;
    }
    
    .project-sidebar,
    .outline-panel,
    .ai-assistant-panel {
        display: none;
    }
}