* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.main-header {
    background-color: #2c3e50;
    color: white;
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 30px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-text h1 {
    font-size: 24px;
    margin-bottom: 10px;
}

.header-text h2 {
    font-size: 16px;
    font-weight: normal;
    margin-bottom: 15px;
    opacity: 0.9;
}

.student-info p {
    margin-bottom: 5px;
}

.student-name {
    font-weight: bold;
    font-size: 18px;
    color: #4a6491;
}

.header-photo img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    border: 3px solid white;
    object-fit: cover;
}

.labs-navigation h2 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 20px;
}

.labs-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    margin-bottom: 30px;
}

.lab-card {
    background: white;
    border-radius: 8px;
    padding: 15px;
    text-decoration: none;
    color: #333;
    display: flex;
    align-items: center;
    border: 1px solid #ddd;
    transition: all 0.3s ease;
}

.lab-card:hover {
    border-color: #4a6491;
    box-shadow: 0 2px 8px rgba(52, 152, 219, 0.2);
}

.lab-number {
    width: 40px;
    height: 40px;
    background-color: #4a6491;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: bold;
    margin-right: 15px;
}

.lab-info h3 {
    font-size: 16px;
    margin-bottom: 5px;
    color: #2c3e50;
}

.lab-info p {
    font-size: 14px;
    color: #666;
}

.main-footer {
    text-align: center;
    padding: 20px;
    color: #666;
    border-top: 1px solid #ddd;
    margin-top: 30px;
}

.lab-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

.lab-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.back-to-main {
    display: inline-block;
    padding: 10px 15px;
    background-color: #4a6491;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    margin-bottom: 15px;
}

.back-to-main:hover {
    background-color: #4a6491;
}

.lab-title h1 {
    color: #2c3e50;
    font-size: 22px;
    margin-bottom: 5px;
}

.lab-title h2 {
    color: #666;
    font-size: 16px;
    font-weight: normal;
}

.lab-navigation {
    display: flex;
    gap: 20px;
}

.sidebar {
    width: 250px;
    background: white;
    border-radius: 5px;
    padding: 20px;
    border: 1px solid #ddd;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-menu li {
    margin-bottom: 8px;
}

.sidebar-menu a {
    display: block;
    padding: 10px 15px;
    color: #333;
    text-decoration: none;
    border-left: 3px solid transparent;
}

.sidebar-menu a:hover {
    background-color: #f5f5f5;
    border-left-color: #4a6491;
}

.sidebar-menu a.active {
    background-color: #4a6491;
    color: white;
    border-left-color: #3b4f73;
}

.lab-content {
    flex: 1;
    background: white;
    border-radius: 5px;
    padding: 30px;
    border: 1px solid #ddd;
    min-height: 600px;
}

.lab-section {
    display: none;
}

.lab-section.active {
    display: block;
}

.section-title {
    color: #2c3e50;
    font-size: 20px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
}

.content-card {
    background-color: #f9f9f9;
    border-radius: 5px;
    padding: 20px;
    margin: 20px 0;
    border-left: 4px solid #4a6491;
}

.content-card h3 {
    color: #2c3e50;
    margin-bottom: 10px;
    font-size: 18px;
}

.content-card h4 {
    color: #4a6491;
    margin: 15px 0 10px;
    font-size: 16px;
}

.code-block {
    background-color: #2c3e50;
    color: white;
    padding: 15px;
    border-radius: 5px;
    margin: 15px 0;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.4;
    white-space: pre;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin: 20px 0;
}

.link-button {
    display: block;
    padding: 15px;
    background: white;
    border: 1px solid #ddd;
    border-radius: 5px;
    text-decoration: none;
    color: #333;
}

.link-button:hover {
    background-color: #f5f5f5;
    border-color: #4a6491;
}

.link-button strong {
    display: block;
    margin-bottom: 5px;
}

.link-button small {
    color: #666;
    font-size: 12px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 15px 0;
}

th, td {
    border: 1px solid #ddd;
    padding: 10px 12px;
    text-align: left;
}

th {
    background-color: #4a6491;
    color: white;
}

tr:nth-child(even) {
    background-color: #f9f9f9;
}

.conclusion-box {
    background-color: #e8f4fc;
    padding: 20px;
    border-radius: 5px;
    margin: 20px 0;
    border-left: 5px solid #4a6491;
}

.conclusion-box h3 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.screenshot-placeholder {
    background-color: #f0f0f0;
    border-radius: 5px;
    padding: 20px;
    text-align: center;
    margin: 15px 0;
    color: #666;
}

@media (max-width: 992px) {
    .labs-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .lab-navigation {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .header-photo {
        margin-top: 20px;
    }
    
    .header-photo img {
        width: 120px;
        height: 120px;
    }
    
    .labs-grid {
        grid-template-columns: 1fr;
    }
    
    .links-grid {
        grid-template-columns: 1fr;
    }
    
    .lab-content {
        padding: 15px;
    }
}