* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    background: #ffffff;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 100;
}

.sidebar-overlay.active {
    display: block;
}

.sidebar {
    position: fixed;
    top: 0;
    right: -320px;
    width: 320px;
    height: 100%;
    background: white;
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.1);
    z-index: 200;
    transition: right 0.3s ease;
    display: flex;
    flex-direction: column;
}

.sidebar.open {
    right: 0;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sidebar-logo {
    font-size: 20px;
    font-weight: 600;
    color: #667eea;
    text-decoration: none;
}

.close-btn {
    background: none;
    border: none;
    font-size: 24px;
    color: #999;
    cursor: pointer;
    padding: 5px 10px;
}

.close-btn:hover {
    color: #333;
}

.sidebar-section {
    padding: 20px;
    overflow-y: auto;
}

.sidebar-section-title {
    font-size: 14px;
    font-weight: 600;
    color: #999;
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.channel-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.channel-item {
    position: relative;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    padding: 10px 14px;
    background: #f5f5f5;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.channel-item:hover {
    background: #667eea;
}

.channel-link {
    flex: 1;
    font-size: 14px;
    color: #666;
    text-decoration: none;
    transition: color 0.2s;
}

.channel-item:hover .channel-link {
    color: white;
}

.expand-icon {
    font-size: 12px;
    color: #999;
    transition: transform 0.2s;
    user-select: none;
    cursor: pointer;
}

.channel-item:hover .expand-icon {
    color: white;
}

.expand-icon.expanded {
    transform: rotate(180deg);
}

.sub-menu {
    display: none;
    width: 100%;
    margin-top: 4px;
    margin-left: 20px;
    padding-left: 14px;
    border-left: 2px solid #ddd;
    box-sizing: border-box;
}

.sub-menu.open {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.channel-item:hover > .sub-menu {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.channel-item:hover > .expand-icon {
    transform: rotate(180deg);
}

.sub-link {
    display: block;
    padding: 8px 14px;
    font-size: 13px;
    color: #666;
    text-decoration: none;
    background: #fafafa;
    border-radius: 6px;
    transition: all 0.2s;
}

.sub-link:hover {
    background: #667eea;
    color: white;
}

.sidebar-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.sidebar-tag {
    background: #f5f5f5;
    color: #666;
    padding: 6px 12px;
    border-radius: 15px;
    font-size: 13px;
    text-decoration: none;
    transition: all 0.2s;
}

.sidebar-tag:hover {
    background: #667eea;
    color: white;
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid #eee;
    margin-top: auto;
}

.sidebar-footer p {
    font-size: 12px;
    color: #999;
    text-align: center;
    margin: 5px 0;
}

.sidebar-footer .copyright {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid #eee;
}

.top-header {
    position: sticky;
    top: 0;
    left: 0;
    right: 0;
    background: white;
    padding: 12px 20px;
    border-bottom: 1px solid #e0e0e0;
    z-index: 50;
    display: flex;
    justify-content: center;
    align-items: center;
}

.header-left {
    position: absolute;
    left: 20px;
    flex-shrink: 0;
}

.header-right {
    position: absolute;
    right: 20px;
    flex-shrink: 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: #333;
}

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

.logo-text {
    font-size: 16px;
    font-weight: 600;
}

.header-center {
    flex: 1;
    display: flex;
    justify-content: center;
}

.channel-nav {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.nav-item {
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    text-decoration: none;
    color: #666;
    transition: all 0.2s;
}

.nav-item.active {
    background: #333;
    color: white;
}

.nav-item:hover:not(.active) {
    background: #f5f5f5;
}

.filter-tabs {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.channel-tab {
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    text-decoration: none;
    color: #666;
    transition: all 0.2s;
}

.channel-tab:hover {
    background: #f5f5f5;
}

.channel-tab.active {
    background: #667eea;
    color: white;
}

.channel-tab.back {
    color: #667eea;
}

.channel-tab.back:hover {
    background: #f0f0ff;
}

.channel-dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-trigger {
    cursor: pointer;
    padding: 8px 16px;
}

.channel-dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 160px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    z-index: 100;
    overflow: hidden;
}

.dropdown-menu a {
    display: block;
    padding: 10px 16px;
    text-decoration: none;
    color: #666;
    font-size: 14px;
    transition: background 0.2s;
}

.dropdown-menu a:hover {
    background: #f5f5f5;
}

.dropdown-menu a.active {
    background: #667eea;
    color: white;
}

.header-right {
    flex-shrink: 0;
}

.menu-toggle {
    width: 36px;
    height: 36px;
    background: none;
    border: none;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    padding: 0;
}

.menu-toggle span {
    width: 20px;
    height: 2px;
    background: #666;
    border-radius: 1px;
}

.notes-container {
    padding: 20px;
    max-width: 100%;
}

.page-container {
    padding: 20px;
    max-width: 100%;
}

.tags-filter {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: #fafafa;
    border-radius: 8px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.filter-label {
    font-size: 14px;
    color: #666;
    font-weight: 500;
}

.filter-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.filter-tag {
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 13px;
    text-decoration: none;
    background: white;
    color: #666;
    border: 1px solid #e0e0e0;
    transition: all 0.2s;
    cursor: pointer;
}

.filter-tag:hover {
    border-color: #667eea;
    color: #667eea;
}

.filter-tag.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.page-wrapper {
    position: relative;
}

.filter-toggle {
    position: fixed;
    top: 80px;
    right: 20px;
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 16px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    box-shadow: 2px 2px 10px rgba(102, 126, 234, 0.3);
    transition: all 0.3s;
}

.filter-toggle:hover {
    background: #5a6fd6;
    transform: translateY(-2px);
}

.filter-panel {
    position: fixed;
    top: 0;
    left: -300px;
    width: 300px;
    height: 100%;
    background: white;
    z-index: 200;
    box-shadow: 2px 0 20px rgba(0, 0, 0, 0.15);
    transition: left 0.3s ease;
    display: flex;
    flex-direction: column;
}

.filter-panel.show {
    left: 0;
}

.filter-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
    background: #f8f9fa;
    border-bottom: 1px solid #e9ecef;
}

.filter-panel-header h3 {
    margin: 0;
    font-size: 16px;
    color: #333;
}

.filter-panel-close {
    width: 28px;
    height: 28px;
    border: none;
    background: #e9ecef;
    border-radius: 50%;
    font-size: 18px;
    color: #666;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.filter-panel-close:hover {
    background: #dee2e6;
}

.filter-panel-body {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
}

.filter-section {
    margin-bottom: 20px;
}

.filter-section h4 {
    margin: 0 0 10px 0;
    font-size: 14px;
    color: #333;
    font-weight: 500;
}

.filter-options-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.filter-options-list label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 13px;
    color: #555;
    padding: 6px 10px;
    border-radius: 6px;
    transition: background 0.2s;
}

.filter-options-list label:hover {
    background: #f8f9fa;
}

.filter-options-list input[type="radio"],
.filter-options-list input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}

.filter-actions {
    padding: 16px;
    border-top: 1px solid #e9ecef;
}

.filter-reset {
    width: 100%;
    padding: 10px;
    border: none;
    background: #e9ecef;
    color: #666;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}

.filter-reset:hover {
    background: #dee2e6;
}

.filter-mask {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 150;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

.filter-mask.show {
    opacity: 1;
    visibility: visible;
}

.selected-filters {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    background: #fafafa;
    border-radius: 8px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.selected-filters-label {
    font-size: 13px;
    color: #666;
    font-weight: 500;
}

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

.selected-filter-tag {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    background: #667eea;
    color: white;
    border-radius: 4px;
    font-size: 12px;
}

.selected-filter-tag .tag-label {
    font-weight: 500;
}

.selected-filter-tag .tag-value {
    margin-left: 4px;
}

.selected-filter-tag .tag-remove {
    width: 18px;
    height: 18px;
    border: none;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border-radius: 50%;
    font-size: 14px;
    cursor: pointer;
    margin-left: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.selected-filter-tag .tag-remove:hover {
    background: rgba(255, 255, 255, 0.3);
}

.clear-all-filters {
    padding: 4px 10px;
    border: 1px solid #dc3545;
    background: transparent;
    color: #dc3545;
    border-radius: 4px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.clear-all-filters:hover {
    background: #dc3545;
    color: white;
}

.notes-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 0 4px;
}

.notes-count {
    font-size: 14px;
    color: #999;
}

.notes-pagination {
    font-size: 14px;
    color: #999;
}

.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.note-card {
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 16px;
    transition: all 0.2s;
}

.note-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border-color: #d0d0d0;
}

.note-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.note-category,
.note-channel {
    padding: 3px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    color: white;
    background: #667eea;
}

.note-channel.knowledge {
    background: #667eea;
}

.note-channel.opinion {
    background: #f87171;
}

.note-channel.news {
    background: #60a5fa;
}

.note-channel.tutorial {
    background: #34d399;
}

.note-channel.review {
    background: #fbbf24;
}

.note-channel.case {
    background: #a78bfa;
}

.note-industry {
    padding: 3px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    background: #f0fdf4;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.note-date {
    font-size: 12px;
    color: #999;
}

.note-title {
    font-size: 15px;
    font-weight: 600;
    color: #333;
    display: block;
    margin-bottom: 8px;
    line-height: 1.4;
}

.note-title a {
    text-decoration: none;
    color: inherit;
}

.note-title:hover,
.note-title a:hover {
    color: #667eea;
}

.note-meta {
    margin-bottom: 8px;
}

.note-alias {
    font-size: 12px;
    color: #999;
    margin-right: 10px;
}

.note-summary {
    font-size: 13px;
    color: #666;
    line-height: 1.5;
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.note-footer {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
    padding-top: 12px;
    border-top: 1px solid #f0f0f0;
}

.note-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.note-tag {
    background: #f5f5f5;
    color: #666;
    padding: 3px 10px;
    border-radius: 6px;
    font-size: 12px;
    text-decoration: none;
    transition: all 0.2s;
    display: inline-block;
}

.note-tag a {
    color: inherit;
    text-decoration: none;
}

.note-tag:hover {
    background: #667eea;
    color: white;
}

.note-tag.obj-tag {
    background: #f0f9ff;
    color: #0369a1;
    border: 1px solid #bae6fd;
}

.note-tag.obj-tag:hover {
    background: #0369a1;
    color: white;
    border-color: #0369a1;
}

.note-tag.req-tag {
    background: #fff7ed;
    color: #c2410c;
    border: 1px solid #fed7aa;
}

.note-tag.req-tag:hover {
    background: #c2410c;
    color: white;
    border-color: #c2410c;
}

.tag-chip {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    background: #667eea;
    color: white;
    border-radius: 4px;
    font-size: 12px;
    margin-right: 6px;
    margin-bottom: 6px;
    border: 1px solid #5a6fd6;
}

.tag-chip.req-tag {
    background: #f87171;
    border-color: #ef4444;
}

.tag-remove {
    margin-left: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
    opacity: 0.8;
}

.tag-remove:hover {
    opacity: 1;
    cursor: pointer;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.breadcrumb a {
    color: #667eea;
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb .separator {
    color: #999;
}

.breadcrumb span:last-child {
    color: #333;
}

.page-title {
    font-size: 24px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
}

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

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    margin-top: 30px;
    padding: 20px 0;
}

.pagination-btn,
.pagebar a {
    background: white;
    border: 1px solid #e0e0e0;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    color: #666;
    text-decoration: none;
}

.pagination-btn:hover,
.pagebar a:hover {
    background: #f5f5f5;
    border-color: #d0d0d0;
}

.pagination-btn.active,
.pagebar a:active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.content-container {
    display: flex;
    gap: 24px;
    padding: 24px;
    max-width: 1400px;
    margin: 0 auto;
}

.toc-sidebar {
    width: 200px;
    flex-shrink: 0;
    position: sticky;
    top: 80px;
    height: fit-content;
}

.toc-card {
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.toc-title {
    font-size: 15px;
    font-weight: 600;
    color: #333;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid #f0f0f0;
}

.page-content {
    flex: 1;
    min-width: 0;
}

.article-card {
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
}

.article-header {
    position: static;
    border-bottom: 1px solid #f0f0f0;
    padding: 24px;
    margin-bottom: 24px;
    background: linear-gradient(135deg, #ffffff 0%, #fafbfc 100%);
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.article-title {
    font-size: 32px;
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 16px;
    line-height: 1.35;
    letter-spacing: -0.5px;
}

.article-summary {
    font-size: 15px;
    color: #666;
    line-height: 1.6;
    margin-bottom: 20px;
    padding: 12px 16px;
    background: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 14px;
    color: #666;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.article-meta .author {
    color: #333;
    font-weight: 500;
}

.article-meta .author span {
    color: #667eea;
    font-weight: 600;
}

.article-meta .date {
    color: #888;
}

.article-meta .separator {
    color: #ddd;
    font-weight: normal;
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
}

.article-tag {
    display: inline-block;
    background: #667eea;
    color: white;
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
    cursor: default;
}

.article-tag a {
    color: white;
    text-decoration: none;
    display: inline;
}

.article-tag:hover {
    background: #5a6fd6;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.article-tag:hover a {
    color: white;
}

.article-tag.knowledge {
    background: #667eea;
}

.article-tag.opinion {
    background: #f87171;
}

.article-tag.news {
    background: #60a5fa;
}

.article-tag.tutorial {
    background: #34d399;
}

.article-tag.review {
    background: #fbbf24;
}

.article-tag.case {
    background: #a78bfa;
}

.article-body {
    color: #333;
    font-size: 16px;
    line-height: 2;
    min-height: 400px;
}

.article-body h2 {
    font-size: 22px;
    font-weight: 600;
    margin: 28px 0 16px;
    color: #2d3748;
    padding-left: 12px;
    border-left: 4px solid #667eea;
    scroll-margin-top: 80px;
}

.article-body p {
    margin-bottom: 16px;
    text-indent: 2em;
    color: #4a5568;
}

.article-body img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 20px 0;
}

.article-body code {
    background: #f5f5f5;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.9em;
    color: #e53e3e;
}

.article-body pre {
    background: #2d3748;
    color: #e2e8f0;
    padding: 15px 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 20px 0;
}

.article-body pre code {
    background: none;
    color: #e2e8f0;
    padding: 0;
}

.article-body ul, .article-body ol {
    margin: 15px 0;
    padding-left: 30px;
}

.article-body li {
    margin-bottom: 10px;
    color: #4a5568;
}

.article-actions {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    padding: 16px;
    background: #fafafa;
    border-radius: 8px;
}

.action-btn {
    background: white;
    border: 1px solid #e0e0e0;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    color: #666;
}

.action-btn:hover {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.article-nav {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    margin-bottom: 24px;
    padding: 16px;
    background: #fafafa;
    border-radius: 8px;
}

.nav-item {
    flex: 1;
}

.nav-item.prev {
    text-align: left;
}

.nav-item.next {
    text-align: right;
}

.nav-label {
    display: block;
    font-size: 12px;
    color: #999;
    margin-bottom: 4px;
}

.nav-link {
    font-size: 14px;
    color: #667eea;
    text-decoration: none;
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.nav-link:hover {
    text-decoration: underline;
}

.related-section {
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 20px;
}

.section-title {
    font-size: 18px;
    font-weight: 600;
    color: #333;
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 1px solid #f0f0f0;
}

.related-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 12px;
}

.related-item {
    background: #fafafa;
    padding: 12px;
    border-radius: 8px;
    transition: all 0.2s;
}

.related-item:hover {
    background: #f0f0f0;
}

.related-item a {
    color: #333;
    text-decoration: none;
    font-size: 14px;
    line-height: 1.5;
    display: block;
}

.related-item a:hover {
    color: #667eea;
}

.content-sidebar {
    width: 280px;
    flex-shrink: 0;
    position: sticky;
    top: 80px;
    height: fit-content;
}

.sidebar-card {
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 16px;
}

.sidebar-card-title {
    font-size: 15px;
    font-weight: 600;
    color: #333;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid #f0f0f0;
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-list li {
    margin-bottom: 8px;
}

.toc-link {
    color: #666;
    text-decoration: none;
    font-size: 13px;
    padding: 6px 8px;
    border-radius: 4px;
    display: block;
    transition: all 0.2s;
}

.toc-link:hover,
.toc-link.active {
    background: #667eea;
    color: white;
}

.tags-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag-cloud-item {
    background: #f5f5f5;
    color: #666;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 12px;
    text-decoration: none;
    transition: all 0.2s;
    display: inline-block;
    cursor: default;
}

.tag-cloud-item:hover {
    background: #667eea;
    color: white;
}

.hot-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.hot-list li {
    margin-bottom: 10px;
    padding-bottom: 10px;
    border-bottom: 1px solid #f0f0f0;
}

.hot-list li:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.hot-list li a {
    color: #333;
    text-decoration: none;
    font-size: 13px;
    line-height: 1.5;
    display: block;
    transition: all 0.2s;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.hot-list li a:hover {
    color: #667eea;
}

.main-footer {
    text-align: center;
    padding: 30px;
    color: #999;
    font-size: 14px;
    border-top: 1px solid #e0e0e0;
    margin-top: 40px;
}

.not-found {
    text-align: center;
    padding: 100px 0;
}

.not-found-text {
    font-size: 18px;
    color: #666;
    margin-top: 20px;
}

.not-found-sub {
    font-size: 14px;
    color: #999;
    margin-top: 10px;
}

.not-found-link {
    display: inline-block;
    margin-top: 30px;
    padding: 10px 24px;
    background: #667eea;
    color: white;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.2s;
}

.not-found-link:hover {
    background: #5a6fd6;
}

.no-results {
    text-align: center;
    padding: 60px 0;
    color: #999;
}

@media (max-width: 1024px) {
    .content-container {
        flex-direction: column;
    }
    
    .toc-sidebar {
        width: 100%;
        position: static;
        order: 2;
    }
    
    .page-content {
        order: 1;
    }
    
    .content-sidebar {
        width: 100%;
        position: static;
        order: 3;
    }
}

@media (max-width: 768px) {
    .top-header {
        flex-wrap: wrap;
        gap: 10px;
    }
    
    .header-center {
        order: 3;
        width: 100%;
    }
    
    .logo-text {
        display: none;
    }
    
    .notes-grid {
        grid-template-columns: 1fr;
    }
    
    .page-title {
        font-size: 20px;
    }
    
    .article-title {
        font-size: 22px;
    }
    
    .article-meta {
        flex-wrap: wrap;
        gap: 8px;
    }
    
    .article-actions {
        flex-wrap: wrap;
    }
    
    .related-list {
        grid-template-columns: 1fr;
    }
    
    .content-container {
        padding: 16px;
        gap: 16px;
    }
    
    .article-card {
        padding: 16px;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .notes-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1025px) and (max-width: 1400px) {
    .notes-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1401px) {
    .notes-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}