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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', sans-serif;
    line-height: 1.7;
    color: #202124;
    background-color: #f8f9fa;
    font-size: 15px;
}

.container-fluid {
    padding: 0;
}

.sidebar {
    background-color: #fff;
    border-right: 1px solid #e5e7eb;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    padding: 0;
}

.sidebar-content {
    padding: 20px 0;
}

.sidebar-title {
    font-size: 14px;
    font-weight: 600;
    color: #5f6368;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 0 20px 12px;
    margin-bottom: 8px;
    border-bottom: 1px solid #e5e7eb;
}

.sidebar .nav-link {
    color: #3c4043;
    padding: 8px 20px;
    font-size: 14px;
    border-left: 3px solid transparent;
    transition: all 0.2s ease;
}

.sidebar .nav-link:hover {
    background-color: #f1f3f4;
    color: #1a73e8;
}

.sidebar .nav-link.active {
    color: #1a73e8;
    background-color: #e8f0fe;
    border-left-color: #1a73e8;
    font-weight: 500;
}

.main-content {
    padding: 25px 40px;
    background-color: #fff;
    min-height: 100vh;
}

.reminder {
    margin-bottom: 25px;
}

.reminder .alert {
    font-size: 14px;
    margin-bottom: 0;
    border-radius: 8px;
}

.article-header {
    padding-bottom: 15px;
    border-bottom: 1px solid #e5e7eb;
    margin-bottom: 25px;
}

.article-title {
    font-size: 32px;
    font-weight: 700;
    color: #202124;
    margin-bottom: 10px;
    line-height: 1.3;
}

.article-meta {
    color: #5f6368;
    font-size: 13px;
}

.article-meta span {
    margin-right: 20px;
}

.article-meta i {
    margin-right: 5px;
}

.article-body {
    max-width: 100%;
}

.section-block {
    margin-bottom: 35px;
}

.section-heading {
    font-size: 24px;
    font-weight: 600;
    color: #202124;
    padding-bottom: 10px;
    border-bottom: 1px solid #e5e7eb;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
}

.section-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    background-color: #1a73e8;
    color: #fff;
    border-radius: 50%;
    font-size: 15px;
    font-weight: 700;
    margin-right: 12px;
}

.infobox {
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    margin-bottom: 20px;
    background-color: #f8f9fa;
}

.infobox-table {
    margin-bottom: 0;
    font-size: 14px;
}

.infobox-table th,
.infobox-table td {
    padding: 12px 15px;
    vertical-align: middle;
    border-color: #e5e7eb;
}

.infobox-label {
    width: 12%;
    background-color: #f1f3f4;
    font-weight: 600;
    color: #3c4043;
}

.infobox-value {
    width: 38%;
    color: #202124;
}

.section-block p {
    font-size: 15px;
    color: #202124;
    line-height: 1.8;
    margin-bottom: 16px;
}

.section-block h4 {
    font-size: 18px;
    font-weight: 600;
    color: #202124;
    margin: 24px 0 12px;
    display: flex;
    align-items: center;
}

.section-block h4 i {
    color: #1a73e8;
    margin-right: 8px;
}

.section-block h5 {
    font-size: 15px;
    font-weight: 600;
    color: #3c4043;
    margin-bottom: 8px;
}

.key-points {
    background-color: #e8f0fe;
    border-radius: 8px;
    padding: 16px 20px;
    margin: 16px 0;
    border-left: 4px solid #1a73e8;
}

.key-points h5 {
    margin-bottom: 10px;
    color: #1a73e8;
}

.key-points ul,
.section-block ul {
    padding-left: 0;
    list-style: none;
    margin-bottom: 15px;
}

.key-points li,
.section-block ul li {
    position: relative;
    padding: 5px 0 5px 20px;
    font-size: 14px;
    line-height: 1.7;
    color: #3c4043;
}

.key-points li::before {
    content: '•';
    position: absolute;
    left: 5px;
    color: #1a73e8;
    font-weight: bold;
}

.section-block ul li::before {
    content: '▪';
    position: absolute;
    left: 0;
    color: #1a73e8;
    font-size: 12px;
}

.principle-list {
    margin-top: 12px;
}

.principle-entry {
    padding: 15px 0;
    border-bottom: 1px solid #f1f3f4;
}

.principle-entry:last-child {
    border-bottom: none;
}

.principle-entry h5 {
    display: flex;
    align-items: center;
    color: #1a73e8;
    margin-bottom: 8px;
}

.principle-entry h5 i {
    margin-right: 8px;
}

.principle-entry p {
    margin-bottom: 0;
    padding-left: 28px;
    color: #5f6368;
    font-size: 14px;
}

.history-timeline {
    border-left: 2px solid #1a73e8;
    padding-left: 25px;
    margin: 20px 0;
}

.history-item {
    position: relative;
    margin-bottom: 25px;
}

.history-item:last-child {
    margin-bottom: 0;
}

.history-item::before {
    content: '';
    position: absolute;
    left: -32px;
    top: 8px;
    width: 12px;
    height: 12px;
    background-color: #1a73e8;
    border-radius: 50%;
    border: 3px solid #fff;
    box-shadow: 0 0 0 2px #1a73e8;
}

.history-year {
    display: inline-block;
    background-color: #1a73e8;
    color: #fff;
    padding: 3px 12px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 10px;
}

.history-content h5 {
    font-size: 16px;
    font-weight: 600;
    color: #202124;
    margin-bottom: 6px;
}

.history-content p {
    margin-bottom: 0;
    color: #5f6368;
    font-size: 14px;
}

.capability-section {
    background-color: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 15px;
}

.capability-section h4 {
    margin-top: 0;
}

.level-table-wrapper {
    overflow-x: auto;
    margin: 16px 0;
}

.level-table {
    font-size: 14px;
    margin-bottom: 0;
}

.level-table thead th {
    background-color: #1a73e8;
    color: #fff;
    font-weight: 600;
    border-color: #1557b0;
    padding: 12px 15px;
}

.level-table tbody td {
    padding: 12px 15px;
    vertical-align: middle;
}

.level-table tbody tr:nth-child(even) {
    background-color: #f8f9fa;
}

.level-badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    color: #fff;
}

.level-5 { background-color: #34a853; }
.level-4 { background-color: #4285f4; }
.level-3 { background-color: #fbbc04; color: #202124; }
.level-2 { background-color: #ea4335; }
.level-1 { background-color: #9334e6; }

.knowledge-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 15px;
    margin: 15px 0;
}

.knowledge-entry {
    background-color: #f8f9fa;
    border-radius: 8px;
    padding: 16px;
    border-left: 4px solid #1a73e8;
}

.knowledge-entry h5 {
    color: #1a73e8;
    margin-bottom: 6px;
}

.knowledge-entry p {
    margin-bottom: 0;
    font-size: 13px;
    color: #5f6368;
}

.tool-tags {
    margin: 10px 0 20px;
}

.tag {
    display: inline-block;
    background-color: #e8f0fe;
    color: #1a73e8;
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 13px;
    margin: 4px 6px 4px 0;
    border: 1px solid #d2e3fc;
    transition: all 0.2s ease;
}

.tag:hover {
    background-color: #d2e3fc;
}

.application-list {
    margin-top: 16px;
}

.application-entry {
    padding: 16px 0;
    border-bottom: 1px solid #f1f3f4;
}

.application-entry:last-child {
    border-bottom: none;
}

.application-entry h4 {
    margin-top: 0;
}

.application-entry p {
    margin-bottom: 0;
    padding-left: 28px;
    font-size: 14px;
    color: #5f6368;
}

.career-path {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    margin: 16px 0;
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 8px;
}

.career-path span {
    background-color: #1a73e8;
    color: #fff;
    padding: 8px 18px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
}

.career-path i {
    color: #9aa0a6;
    font-size: 16px;
}

.literacy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
    margin-top: 16px;
}

.literacy-entry {
    background-color: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
}

.literacy-entry h4 {
    margin-top: 0;
    color: #1a73e8;
}

.literacy-entry h4 i {
    color: #1a73e8;
}

.literacy-entry ul {
    margin-bottom: 0;
}

.article-footer {
    margin-top: 40px;
    padding-top: 25px;
    border-top: 1px solid #e5e7eb;
}

.footer-content {
    text-align: center;
    color: #5f6368;
    font-size: 13px;
}

.footer-content p {
    margin-bottom: 8px;
}

.footer-content a {
    color: #1a73e8;
    text-decoration: none;
}

.footer-content a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    .sidebar {
        display: none;
    }
    
    .main-content {
        padding: 15px;
    }
    
    .article-title {
        font-size: 24px;
    }
    
    .section-heading {
        font-size: 20px;
    }
    
    .knowledge-grid,
    .literacy-grid {
        grid-template-columns: 1fr;
    }
    
    .career-path {
        flex-direction: column;
    }
    
    .career-path i {
        transform: rotate(90deg);
    }
    
    .infobox-label,
    .infobox-value {
        width: 50%;
    }
}