/* Navigation Buttons */
.nav-buttons {
    display: flex;
    justify-content: space-between;
    margin: 2rem 0;
    padding: 1rem 0;
    border-bottom: 1px solid #e5e7eb;
}

/* Top navigation buttons */
.nav-buttons.top-navigation {
    margin-top: 0;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #e5e7eb;
}

/* Bottom navigation buttons */
.nav-buttons:not(.top-navigation) {
    margin-top: 3rem;
    margin-bottom: 1rem;
    padding-top: 1.5rem;
    border-top: 1px solid #e5e7eb;
    border-bottom: none;
}

.nav-btn {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    background-color: #f3f4f6;
    color: #1f2937;
    border-radius: 0.375rem;
    font-weight: 500;
    transition: all 0.3s ease;
    text-decoration: none;
    border: 1px solid #e5e7eb;
}

.nav-btn:hover {
    background-color: #e5e7eb;
    transform: translateY(-2px);
}

.nav-btn i {
    margin: 0 0.5rem;
}

.nav-prev i {
    margin-right: 0.5rem;
}

.nav-next i {
    margin-left: 0.5rem;
}

/* Content Styling */
.lesson-content {
    font-size: 1rem;
    line-height: 1.6;
    color: #374151;
}

.lesson-content h1 {
    font-size: 1.75rem;
    margin: 0.5rem 0 1rem 0;
    color: #111827;
    line-height: 1.2;
}

.lesson-content h2 {
    font-size: 1.5rem;
    margin: 1.75rem 0 1.25rem;
    color: #111827;
    padding-top: 0.75rem;
    border-top: 1px solid #e5e7eb;
}

.lesson-content h3 {
    font-size: 1.25rem;
    margin: 1.5rem 0 1rem;
    color: #1f2937;
}

.lesson-content p {
    margin-bottom: 1rem;
    color: #4b5563;
    font-size: 0.95rem;
}

.lesson-content ul, 
.lesson-content ol {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
}

.lesson-content li {
    margin-bottom: 0.4rem;
    color: #4b5563;
    font-size: 0.95rem;
}

/* Computer Software Page Styles */
.software-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.software-category {
    background: #f8f9ff;
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid #4a6bff;
}

.software-category:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.software-category i {
    font-size: 2rem;
    color: #4a6bff;
    margin-bottom: 1rem;
}

.software-category h4 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.2rem;
}

.software-category ul {
    list-style: none;
    padding: 0;
    margin: 0;
    text-align: left;
}

.software-category li {
    padding: 0.5rem 0;
    color: #444;
    border-bottom: 1px solid #eee;
}

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

.comparison-container {
    display: flex;
    gap: 2rem;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.comparison-box {
    flex: 1;
    min-width: 250px;
    background: #ffffff;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    border-top: 4px solid #6c5bff;
}

.comparison-box h4 {
    margin-top: 0;
    color: #2c3e50;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.vs-separator {
    display: flex;
    align-items: center;
    font-weight: bold;
    color: #666;
}

.app-types {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.app-type {
    background: #f8f9ff;
    border-radius: 8px;
    padding: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid #4a6bff;
}

.app-type h3 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.app-type ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.app-type li {
    padding: 0.5rem 0;
    color: #444;
    border-bottom: 1px solid #eee;
}

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

/* Output Devices Page Styles */
.categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.category {
    background: #f8f9ff;
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid #4a6bff;
}

.category:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.category i {
    font-size: 2rem;
    color: #4a6bff;
    margin-bottom: 1rem;
}

.category h5 {
    margin: 0.5rem 0;
    color: #2c3e50;
    font-size: 1.1rem;
}

.category p {
    margin: 0;
    font-size: 0.9rem;
    color: #555;
    line-height: 1.5;
}

.device-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.device-card {
    background: #ffffff;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-top: 4px solid #4a6bff;
}

.device-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.device-icon {
    font-size: 2rem;
    color: #4a6bff;
    margin-bottom: 1rem;
}

.device-info h3 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.3rem;
}

.device-info ul {
    padding-left: 1.2rem;
    margin: 0;
}

.device-info li {
    margin-bottom: 0.5rem;
    line-height: 1.5;
    color: #444;
}

.device-info li strong {
    color: #2c3e50;
}

.comparison-box {
    background: #f8f9ff;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 2rem 0;
    border-left: 4px solid #6c5bff;
}

.comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 1rem;
}

.printer-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.printer-card {
    background: #ffffff;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-top: 4px solid #6c5bff;
}

.printer-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.printer-icon {
    font-size: 2rem;
    color: #6c5bff;
    margin-bottom: 1rem;
}

.printer-card h3 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.2rem;
}

.port-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.port-card {
    display: flex;
    background: #ffffff;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid #4a6bff;
}

.port-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.port-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 1.5rem;
    flex-shrink: 0;
}

.port-icon.usb { background: #f0f4ff; color: #4a6bff; }
.port-icon.hdmi { background: #fff0f0; color: #ff4a4a; }
.port-icon.vga { background: #f0fff0; color: #4caf50; }
.port-icon.ethernet { background: #f0f0ff; color: #6c5bff; }
.port-icon.audio { background: #fff8f0; color: #ff9800; }

.port-info h3 {
    margin: 0 0 0.8rem 0;
    color: #2c3e50;
    font-size: 1.2rem;
}

.port-info ul {
    padding-left: 1.2rem;
    margin: 0;
}

.port-info li {
    margin-bottom: 0.4rem;
    font-size: 0.95rem;
    color: #444;
    line-height: 1.5;
}

.port-info li strong {
    color: #2c3e50;
}

.success-message {
    background: #e8f5e9;
    color: #2e7d32;
    padding: 0.8rem 1rem;
    border-radius: 4px;
    margin-top: 1rem;
    font-size: 0.95rem;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Memory Page Styles */
.memory-units {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.memory-unit {
    background: #f0f4ff;
    border-radius: 8px;
    padding: 1rem;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid #4a6bff;
}

.memory-unit:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.memory-unit h4 {
    margin: 0 0 0.5rem 0;
    color: #2c3e50;
    font-size: 1.1rem;
}

.memory-unit p {
    margin: 0;
    font-size: 0.9rem;
    color: #555;
}

.comparison-table {
    margin: 2rem 0;
    overflow-x: auto;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    font-size: 0.95rem;
}

.comparison-table th,
.comparison-table td {
    padding: 1rem;
    text-align: left;
    border: 1px solid #e0e0e0;
}

.comparison-table th {
    background-color: #f5f7ff;
    font-weight: 600;
    color: #2c3e50;
}

.comparison-table tr:nth-child(even) {
    background-color: #fafbff;
}

.comparison-table tr:hover {
    background-color: #f0f4ff;
}

.memory-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.memory-card {
    background: #ffffff;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-top: 4px solid #4a6bff;
}

.memory-card.primary {
    border-top-color: #4a6bff;
}

.memory-card.secondary {
    border-top-color: #6c5bff;
}

.memory-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.memory-icon {
    font-size: 2rem;
    color: #4a6bff;
    margin-bottom: 1rem;
}

.memory-card h3 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.3rem;
}

.memory-card ul {
    padding-left: 1.2rem;
    margin: 0;
}

.memory-card li {
    margin-bottom: 0.5rem;
    line-height: 1.5;
    color: #444;
}

.memory-card li strong {
    color: #2c3e50;
}

/* Motherboard and Data Bus Page Styles */
.bus-types {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.bus-type {
    background: #f5f7ff;
    border-radius: 8px;
    padding: 1.2rem;
    border-left: 4px solid #4a6bff;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.bus-type:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.bus-type h5 {
    color: #2c3e50;
    margin: 0 0 0.8rem 0;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.bus-type p {
    margin: 0.5rem 0;
    font-size: 0.95rem;
    color: #444;
}

.bus-type p strong {
    color: #2c3e50;
}

.bus-characteristics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.characteristic {
    text-align: center;
    padding: 1.5rem 1rem;
    background: #f8f9ff;
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.characteristic:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.characteristic i {
    font-size: 2rem;
    color: #4a6bff;
    margin-bottom: 1rem;
}

.characteristic h4 {
    margin: 0.5rem 0;
    color: #2c3e50;
}

.characteristic p {
    font-size: 0.9rem;
    color: #666;
    margin: 0.5rem 0 0;
}

/* CPU Page Styles */
.component-cards {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin: 2rem 0;
}

.component-card {
    display: flex;
    background: #f8f9ff;
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid #6c5bff;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.component-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.component-icon {
    font-size: 2rem;
    color: #4a6bff;
    margin-right: 1.5rem;
    min-width: 50px;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 0.5rem;
}

.component-info {
    flex: 1;
}

.component-info h3 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.matching-activity {
    margin: 1.5rem 0;
}

.matching-pairs {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.matching-item,
.matching-target {
    padding: 1rem;
    border: 2px dashed #ddd;
    border-radius: 8px;
    text-align: center;
    cursor: move;
    background: white;
    transition: all 0.3s ease;
}

.matching-target {
    background: #f8f9ff;
    border-style: solid;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.matching-item.dragging {
    opacity: 0.5;
}

.matching-item:hover {
    background: #f0f4ff;
    border-color: #4a6bff;
}

/* Input Devices Page Styles */
.device-section {
    margin: 2rem 0;
}

.device-card {
    display: flex;
    background: #f8f9ff;
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid #4a6bff;
}

.device-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.device-icon {
    font-size: 2.5rem;
    color: #4a6bff;
    margin-right: 1.5rem;
    min-width: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.device-info h3 {
    margin: 0 0 0.5rem 0;
    color: #2c3e50;
    font-size: 1.3rem;
}

.device-info p {
    margin: 0;
    color: #555;
    line-height: 1.6;
}

.learning-objectives {
    background: #f0f4ff;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 2rem 0;
    border-left: 4px solid #4a6bff;
}

.learning-objectives h3 {
    margin-top: 0;
    color: #2c3e50;
    font-size: 1.2rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.learning-objectives ul {
    padding-left: 1.5rem;
    margin: 0;
}

.learning-objectives li {
    margin-bottom: 0.5rem;
    color: #444;
    position: relative;
    padding-left: 1.5rem;
}

.learning-objectives li:before {
    content: "→";
    color: #4a6bff;
    position: absolute;
    left: 0;
}

.navigation-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid #eee;
}

.nav-button {
    padding: 0.8rem 1.5rem;
    border-radius: 6px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-button.prev {
    background: #f0f4ff;
    color: #4a6bff;
    border: 1px solid #d0d8ff;
}

.nav-button.next {
    background: #4a6bff;
    color: white;
    border: 1px solid #4a6bff;
    margin-left: auto;
}

.nav-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* Lesson Page Styles */
.lesson-container {
    display: flex;
    max-width: 1400px;
    margin: 6rem auto 2rem;
    padding: 0 20px;
    gap: 2rem;
}

/* Sidebar Styles */
.lesson-sidebar {
    width: 280px;
    position: sticky;
    top: 80px;
    align-self: flex-start;
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    height: calc(100vh - 100px);
    overflow-y: auto;
}

.lesson-toc h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.lesson-toc ul {
    list-style: none;
    padding-left: 1rem;
}

.lesson-toc li {
    margin-bottom: 0.5rem;
    position: relative;
}

.lesson-toc a {
    color: var(--secondary-color);
    font-size: 0.95rem;
    transition: var(--transition);
    display: block;
    padding: 0.3rem 0;
}

.lesson-toc a:hover,
.lesson-toc a.active {
    color: var(--primary-color);
    padding-left: 5px;
}

.lesson-toc ul ul {
    margin-top: 0.3rem;
    border-left: 2px solid #eee;
    padding-left: 1rem;
}

.lesson-toc ul ul a {
    font-size: 0.9rem;
    color: #6c757d;
}

.lesson-progress {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid #eee;
}

.lesson-progress h4 {
    font-size: 1rem;
    margin-bottom: 0.8rem;
    color: var(--dark-color);
}

.progress-bar {
    height: 8px;
    background-color: #e9ecef;
    border-radius: 4px;
    margin-bottom: 0.5rem;
    overflow: hidden;
}

.progress {
    height: 100%;
    background: linear-gradient(90deg, #4a6bff, #6c5bff);
    border-radius: 4px;
    transition: width 0.5s ease;
}

.lesson-progress p {
    font-size: 0.9rem;
    color: var(--secondary-color);
    text-align: right;
}

/* Main Content Styles */
.lesson-content {
    flex: 1;
    background: white;
    border-radius: 10px;
    padding: 2.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.lesson-content h1 {
    font-size: 2.2rem;
    color: var(--dark-color);
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #f0f2ff;
}

.lesson-section {
    margin-bottom: 3rem;
}

.lesson-section h2 {
    font-size: 1.8rem;
    color: var(--dark-color);
    margin: 2.5rem 0 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid #eee;
}

.lesson-section h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin: 2rem 0 1.2rem;
}

.lesson-section h4 {
    font-size: 1.2rem;
    color: var(--dark-color);
    margin: 1.8rem 0 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lesson-section p {
    margin-bottom: 1.2rem;
    line-height: 1.7;
    color: #444;
}

.lesson-section ul, 
.lesson-section ol {
    margin: 1.2rem 0;
    padding-left: 2rem;
}

.lesson-section li {
    margin-bottom: 0.6rem;
    line-height: 1.6;
}

/* Special Content Boxes */
.definition-box {
    background-color: #f8f9ff;
    border-left: 4px solid var(--primary-color);
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 5px 5px 0;
}

.definition-box h4 {
    margin-top: 0;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.definition-box p {
    margin-bottom: 0;
}

.real-world-example {
    background-color: #fff9f0;
    border-left: 4px solid #ffb74d;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 5px 5px 0;
}

.real-world-example h4 {
    color: #ff9800;
}

.interactive-activity {
    background-color: #f0f9f5;
    border-left: 4px solid #4caf50;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 5px 5px 0;
}

.interactive-activity h4 {
    color: #2e7d32;
}

/* Feature Cards */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.8rem;
    margin: 2.5rem 0;
}

.feature-intro {
    font-size: 1.1rem;
    color: #4a5568;
    margin-bottom: 2rem;
    line-height: 1.7;
    max-width: 800px;
}

.feature-card {
    background: #ffffff;
    border-radius: 12px;
    padding: 1.8rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
    position: relative;
    overflow: hidden;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    border-color: #cbd5e0;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, #4a6bff, #6c5bff);
    transition: width 0.3s ease;
}

.feature-card:hover::before {
    width: 6px;
}

.feature-icon {
    font-size: 2rem;
    color: #4a6bff;
    margin-bottom: 1.5rem;
    display: inline-block;
    background: rgba(74, 107, 255, 0.1);
    width: 64px;
    height: 64px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.feature-card:hover .feature-icon {
    transform: scale(1.1);
    background: rgba(74, 107, 255, 0.15);
}

.feature-card h5 {
    color: #2d3748;
    margin: 1.2rem 0 1.2rem 0;
    font-size: 1.35rem;
    font-weight: 600;
    position: relative;
    padding-bottom: 0.8rem;
}

.feature-card h5::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 3px;
    background: #4a6bff;
    border-radius: 3px;
}

/* Storage Table */
.storage-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.storage-table td {
    padding: 0.75rem 0.5rem;
    text-align: center;
    border: 1px solid #e2e8f0;
    font-size: 0.95rem;
    color: #4a5568;
    transition: all 0.2s ease;
}

.storage-table tr:nth-child(even) {
    background: #f8fafc;
}

.storage-table tr:hover td {
    background: #f1f5f9;
    color: #2d3748;
}

/* Info Tables */
.info-table {
    margin: 1rem 0;
    overflow-x: auto;
}

.info-table table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.info-table th, 
.info-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border: 1px solid #e2e8f0;
}

.info-table th {
    background: #f8fafc;
    font-weight: 600;
    color: #2d3748;
}

.info-table tr:nth-child(even) {
    background: #f8fafc;
}

.info-table tr:hover {
    background: #f1f5f9;
}

/* Feature Icons and Styling */
.features-intro i {
    color: #4a6bff;
    margin-right: 8px;
}

.feature-item {
    position: relative;
    padding-left: 40px;
    margin-bottom: 1.5rem;
}

.feature-icon {
    position: absolute;
    left: 0;
    top: 0;
    width: 32px;
    height: 32px;
    background: rgba(74, 107, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4a6bff;
    font-size: 1.1rem;
}

/* Application Lists */
.applications-intro {
    margin: 1rem 0 1.5rem 1.5rem;
    color: #4a5568;
    line-height: 1.7;
}

.applications-intro li {
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.applications-intro li:before {
    content: '•';
    color: #4a6bff;
    font-weight: bold;
    position: absolute;
    left: 0;
}

.application-list {
    margin: 0.5rem 0 1.5rem 2rem;
    color: #4a5568;
    line-height: 1.7;
    list-style-type: none;
    padding: 0;
}

.application-list li {
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.8rem;
    transition: all 0.2s ease;
}

.application-list li:before {
    content: '✓';
    color: #4a6bff;
    font-weight: bold;
    position: absolute;
    left: 0;
    width: 1.5rem;
    text-align: center;
    transition: all 0.2s ease;
}

.application-list li:hover {
    color: #2d3748;
    transform: translateX(3px);
}

.application-list li:hover:before {
    color: #3a56d9;
    transform: scale(1.2);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .application-list {
        margin-left: 1.5rem;
    }
    
    .application-list li {
        padding-left: 1.5rem;
    }
}

/* Application Section Icons */
#applications h4 {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #2d3748;
    margin-top: 1.8rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e2e8f0;
}

#applications h4 i {
    width: 32px;
    height: 32px;
    background: rgba(74, 107, 255, 0.1);
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #4a6bff;
    font-size: 1.1rem;
}

/* Color variations for different application icons */
#applications h4:nth-child(3) i { background: rgba(74, 222, 128, 0.15); color: #10b981; } /* Education */
#applications h4:nth-child(5) i { background: rgba(96, 165, 250, 0.15); color: #3b82f6; } /* Communication */
#applications h4:nth-child(7) i { background: rgba(248, 113, 113, 0.15); color: #ef4444; } /* Banking */
#applications h4:nth-child(9) i { background: rgba(244, 114, 182, 0.15); color: #ec4899; } /* Medicine */
#applications h4:nth-child(11) i { background: rgba(251, 191, 36, 0.15); color: #f59e0b; } /* Entertainment */
#applications h4:nth-child(13) i { background: rgba(139, 92, 246, 0.15); color: #8b5cf6; } /* Scientific Research */
#applications h4:nth-child(15) i { background: rgba(20, 184, 166, 0.15); color: #14b8a6; } /* Agriculture */

/* Feature Content Styles */
.feature-card p {
    color: #4a5568;
    line-height: 1.7;
    margin-bottom: 1.2rem;
    font-size: 1.02rem;
}

.feature-list {
    padding-left: 1.2rem;
    margin: 1rem 0;
}

.feature-list li {
    margin-bottom: 0.5rem;
    color: #4a5568;
    line-height: 1.6;
}

.example {
    font-weight: 500;
    color: #4a6bff;
    font-style: italic;
    margin-right: 0.3rem;
}

/* Speed Table */
.speed-table {
    width: 100%;
    margin: 1.2rem 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    border: 1px solid #e2e8f0;
}

.table-header {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    background: #f8fafc;
    font-weight: 600;
    color: #2d3748;
    border-bottom: 1px solid #e2e8f0;
}

.table-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    background: white;
    transition: background 0.2s ease;
}

.table-row:nth-child(even) {
    background: #f8fafc;
}

.table-row:hover {
    background: #f1f5f9;
}

.table-header span,
.table-row span {
    padding: 0.8rem 1rem;
    text-align: left;
    border-right: 1px solid #e2e8f0;
}

.table-row span {
    color: #4a5568;
}

/* Storage Units */
.storage-units {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.8rem;
    margin: 1.2rem 0;
}

.storage-unit {
    background: #f8fafc;
    padding: 0.8rem 1rem;
    border-radius: 6px;
    font-family: 'Fira Code', monospace, monospace;
    font-size: 0.95rem;
    color: #2d3748;
    border: 1px solid #e2e8f0;
    transition: all 0.2s ease;
}

.storage-unit:hover {
    background: #f1f5f9;
    transform: translateX(4px);
    border-color: #cbd5e0;
}

/* IPOS Cycle */
.ipos-intro {
    background: #f8fafc;
    border-left: 4px solid #4a6bff;
    padding: 1.2rem 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 8px 8px 0;
}

.ipos-intro p {
    margin: 0;
    color: #4a5568;
    line-height: 1.6;
}

.ipos-intro strong {
    color: #2d3748;
    font-weight: 600;
}

.ipos-diagram {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    margin: 2rem 0;
    gap: 1.5rem;
}

.ipos-box {
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    width: 200px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
}

.ipos-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
}

.ipos-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
}

.ipos-box.input::before { background: #4a6bff; }
.ipos-box.process::before { background: #10b981; }
.ipos-box.output::before { background: #f59e0b; }
.ipos-box.storage::before { background: #8b5cf6; }

.ipos-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #4a6bff;
    background: rgba(74, 107, 255, 0.1);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.ipos-box.process .ipos-icon {
    color: #10b981;
    background: rgba(16, 185, 129, 0.1);
}

.ipos-box.output .ipos-icon {
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.1);
}

.ipos-box.storage .ipos-icon {
    color: #8b5cf6;
    background: rgba(139, 92, 246, 0.1);
}

.ipos-box h4 {
    margin: 0.5rem 0;
    color: #2d3748;
    font-size: 1.2rem;
}

.ipos-box p {
    margin: 0.5rem 0 0;
    color: #4a5568;
    font-size: 0.95rem;
    line-height: 1.5;
}

.ipos-arrow {
    color: #cbd5e0;
    font-size: 1.5rem;
    margin: 0 0.5rem;
}

.ipos-cycle {
    text-align: center;
    margin: 2rem 0;
    padding: 1.5rem;
    background: #f8fafc;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.cycle-arrow {
    width: 50px;
    height: 50px;
    background: #4a6bff;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    animation: spin 4s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.ipos-cycle p {
    margin: 0;
    color: #4a5568;
    font-style: italic;
}

/* Responsive adjustments */
@media (max-width: 1024px) {
    .ipos-diagram {
        gap: 1rem;
    }
    
    .ipos-box {
        width: calc(50% - 1rem);
        margin-bottom: 1rem;
    }
    
    .ipos-arrow {
        transform: rotate(90deg);
        margin: 0.5rem 0;
    }
}

@media (max-width: 640px) {
    .ipos-box {
        width: 100%;
    }
    
    .ipos-arrow {
        transform: rotate(90deg);
        margin: 0.5rem 0;
    }
}
.ipos-cycle {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin: 2.5rem 0;
    gap: 1.5rem;
}

.ipos-step {
    flex: 1;
    min-width: 200px;
    text-align: center;
    padding: 1.5rem;
    background: #f8f9ff;
    border-radius: 10px;
    position: relative;
}

.ipos-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, #4a6bff, #6c5bff);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
    font-size: 1.8rem;
    box-shadow: 0 5px 15px rgba(74, 107, 255, 0.3);
}

.ipos-step h4 {
    font-size: 1.2rem;
    margin: 1rem 0 0.8rem;
    color: var(--dark-color);
}

.ipos-step p {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.ipos-step strong {
    color: var(--dark-color);
}

.ipos-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1.5rem;
    align-self: center;
}

/* Applications Container */
.applications-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.application-card {
    display: flex;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
    border: 1px solid #eee;
}

.application-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.app-icon {
    width: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: white;
}

.app-icon.education { background-color: #4a6bff; }
.app-icon.healthcare { background-color: #ff6b6b; }
.app-icon.business { background-color: #20c997; }
.app-icon.entertainment { background-color: #f783ac; }

.app-content {
    flex: 1;
    padding: 1.2rem;
}

.app-content h5 {
    font-size: 1.1rem;
    margin: 0 0 0.8rem;
    color: var(--dark-color);
}

.app-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.app-content li {
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
    color: #555;
    position: relative;
    padding-left: 1.2rem;
}

.app-content li:before {
    content: '•';
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* Interactive Elements */
.activity-answer {
    margin-top: 1rem;
}

.activity-answer textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: 'Poppins', sans-serif;
    font-size: 1rem;
    margin-bottom: 1rem;
    min-height: 100px;
    resize: vertical;
    transition: border-color 0.3s ease;
}

.activity-answer textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 107, 255, 0.1);
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark-color);
}

.form-group input[type="text"] {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: 'Poppins', sans-serif;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 107, 255, 0.1);
}

/* IPOS Diagram */
.ipos-diagram {
    background: #f8f9ff;
    border-radius: 10px;
    padding: 1.5rem;
    margin: 2rem 0;
    text-align: center;
}

.diagram-container {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin: 1.5rem 0;
}

.diagram-box {
    background: white;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    font-weight: 600;
    min-width: 120px;
    text-align: center;
}

.diagram-arrow {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.diagram-arrow.loop {
    flex-basis: 100%;
    margin-top: -1rem;
}

.diagram-caption {
    font-size: 0.9rem;
    color: #666;
    font-style: italic;
    margin-top: 1rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .lesson-container {
        flex-direction: column;
    }
    
    .lesson-sidebar {
        width: 100%;
        position: static;
        height: auto;
        margin-bottom: 2rem;
    }
    
    .lesson-content {
        padding: 1.5rem;
    }
}

@media (max-width: 768px) {
    .ipos-cycle {
        flex-direction: column;
    }
    
    .ipos-arrow {
        transform: rotate(90deg);
        margin: 0.5rem 0;
    }
    
    .applications-container {
        grid-template-columns: 1fr;
    }
    
    .lesson-content {
        padding: 1.25rem;
    }
    
    .lesson-content h1 {
        font-size: 1.8rem;
    }
    
    .lesson-section h2 {
        font-size: 1.5rem;
    }
    
    .lesson-section h3 {
        font-size: 1.3rem;
    }
}

/* Print Styles */
@media print {
    .lesson-sidebar,
    .interactive-activity,
    .hamburger,
    footer {
        display: none !important;
    }
    
    .lesson-container {
        margin: 0;
        padding: 0;
    }
    
    .lesson-content {
        padding: 0 !important;
        box-shadow: none !important;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
        color: #000;
        background: none;
    }
    
    h1, h2, h3, h4, h5, h6 {
        page-break-after: avoid;
    }
    
    .lesson-section {
        page-break-inside: avoid;
    }
    
    a {
        text-decoration: none;
        color: #000;
    }
    
    .definition-box,
    .real-world-example {
        border: 1px solid #ddd;
        page-break-inside: avoid;
    }
}