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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
}

header {
    background: #333;
    color: white;
    padding: 1rem;
}

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

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 2rem;
}

nav ul li a {
    color: white;
    text-decoration: none;
}

main {
    padding: 2rem;
}

.hero {
    text-align: center;
    padding: 3rem 0;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.btn {
    display: inline-block;
    background: #007bff;
    color: white;
    padding: 0.5rem 1rem;
    text-decoration: none;
    border-radius: 3px;
}

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

.feature {
    text-align: center;
    padding: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
}

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

.plan {
    text-align: center;
    padding: 2rem;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.price {
    font-size: 1.5rem;
    font-weight: bold;
    margin: 1rem 0;
}

.plan ul {
    list-style: none;
    margin: 1rem 0;
}

.plan ul li {
    margin: 0.5rem 0;
}

.login-container {
    max-width: 400px;
    margin: 5rem auto;
    padding: 2rem;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.login-container h1 {
    text-align: center;
    margin-bottom: 2rem;
}

.login-container input {
    width: 100%;
    padding: 0.5rem;
    margin: 0.5rem 0;
    border: 1px solid #ddd;
    border-radius: 3px;
}

.login-container button {
    width: 100%;
    padding: 0.5rem;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

.error {
    color: red;
    text-align: center;
    margin-top: 1rem;
}

.contact form {
    max-width: 500px;
    margin: 0 auto;
}

.contact form input,
.contact form textarea {
    width: 100%;
    padding: 0.5rem;
    margin: 0.5rem 0;
    border: 1px solid #ddd;
    border-radius: 3px;
}

.contact form textarea {
    height: 100px;
}

.contact form button {
    width: 100%;
    padding: 0.5rem;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

.contact-info {
    margin-top: 2rem;
    text-align: center;
}

footer {
    background: #333;
    color: white;
    padding: 2rem 0 1rem;
    margin-top: 3rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 0 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: #fff;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin: 0.5rem 0;
}

.footer-section ul li a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section ul li a:hover {
    color: #fff;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-link {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s;
}

.social-link:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    margin-top: 2rem;
    border-top: 1px solid #555;
}

.dashboard {
    padding: 2rem;
}

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

.stat {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    text-align: center;
}

.stat .number {
    font-size: 2rem;
    font-weight: bold;
    color: #007bff;
}

.actions {
    margin: 2rem 0;
}

.course-form {
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin: 1rem 0;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 3px;
}

.form-group textarea {
    height: 100px;
    resize: vertical;
}

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

.course-card {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    border: 1px solid #ddd;
}

.course-card h3 {
    margin-bottom: 0.5rem;
    color: #333;
}

.course-card .price {
    font-size: 1.2rem;
    font-weight: bold;
    color: #007bff;
    margin: 0.5rem 0;
}

.course-card .status {
    color: #666;
    font-size: 0.9rem;
}

.course-card .actions {
    margin-top: 1rem;
}

.course-card .actions .btn {
    margin-right: 0.5rem;
    font-size: 0.9rem;
    padding: 0.3rem 0.8rem;
}

.add-user {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 5px;
    margin: 2rem 0;
}

.user-form {
    max-width: 500px;
}

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

.user-card {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    border: 1px solid #ddd;
}

.user-card h3 {
    margin-bottom: 0.5rem;
    color: #333;
}

.user-card p {
    margin: 0.3rem 0;
    color: #666;
}

.buy-form {
    margin-top: 1rem;
}

.buy-form .form-group {
    margin: 0.5rem 0;
}

.buy-form input {
    width: 80px;
    padding: 0.3rem;
}

.purchases-list {
    margin: 2rem 0;
}

.purchase-item {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    margin: 1rem 0;
    border: 1px solid #ddd;
}

.purchase-item h4 {
    margin-bottom: 0.5rem;
    color: #333;
}

.purchase-item p {
    margin: 0.3rem 0;
    color: #666;
}

.recent-purchases {
    margin: 2rem 0;
}

.message {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 1rem 2rem;
    border-radius: 5px;
    color: white;
    z-index: 1000;
    animation: slideIn 0.3s ease;
}

.message.info {
    background: #007bff;
}

.message.success {
    background: #28a745;
}

.message.error {
    background: #dc3545;
}

.message.warning {
    background: #ffc107;
    color: #333;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

.password-toggle {
    background: none;
    border: none;
    color: #007bff;
    cursor: pointer;
    font-size: 0.9rem;
    margin-left: 0.5rem;
}

.search-input {
    width: 100%;
    max-width: 300px;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 3px;
    margin-bottom: 1rem;
}

.tab {
    background: #f8f9fa;
    border: 1px solid #ddd;
    padding: 0.5rem 1rem;
    cursor: pointer;
    border-bottom: none;
}

.tab.active {
    background: white;
    border-bottom: 2px solid #007bff;
}

.tab-content {
    display: none;
    padding: 1rem;
    border: 1px solid #ddd;
    border-top: none;
}

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

.load-more-btn {
    background: #007bff;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 3px;
    cursor: pointer;
    margin-top: 1rem;
}

.progress-bar {
    width: 100%;
    height: 20px;
    background: #f8f9fa;
    border-radius: 10px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: #007bff;
    transition: width 0.3s ease;
}

.sidebar {
    width: 250px;
    background: #f8f9fa;
    padding: 1rem;
    transition: width 0.3s ease;
}

.sidebar.collapsed {
    width: 60px;
}

.main-content {
    flex: 1;
    padding: 1rem;
    transition: margin-left 0.3s ease;
}

.main-content.expanded {
    margin-left: 0;
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    nav ul {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #333;
        padding: 1rem;
    }
    
    nav ul.active {
        display: flex;
    }
    
    nav ul li {
        margin: 0.5rem 0;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .feature-grid,
    .plans-grid,
    .courses-grid,
    .users-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .social-links {
        justify-content: center;
    }
    
    .sidebar {
        width: 100%;
        position: fixed;
        top: 0;
        left: -100%;
        height: 100vh;
        z-index: 1000;
        transition: left 0.3s ease;
    }
    
    .sidebar.active {
        left: 0;
    }
    
    .main-content {
        margin-left: 0;
    }
}

@media (max-width: 480px) {
    main {
        padding: 1rem;
    }
    
    .hero {
        padding: 2rem 0;
    }
    
    .hero h1 {
        font-size: 1.5rem;
    }
    
    .login-container,
    .course-form,
    .user-form {
        margin: 2rem 1rem;
        padding: 1rem;
    }
}

.about {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

.about h1 {
    text-align: center;
    margin-bottom: 2rem;
    color: #333;
}

.about-content {
    display: grid;
    gap: 2rem;
    margin-top: 2rem;
}

.about-section {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 5px;
    border: 1px solid #ddd;
}

.about-section h2 {
    color: #007bff;
    margin-bottom: 1rem;
}

.about-section ul {
    list-style: none;
    padding-left: 0;
}

.about-section ul li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #eee;
}

.about-section ul li:last-child {
    border-bottom: none;
}

.about-section ul li:before {
    content: "✓";
    color: #28a745;
    font-weight: bold;
    margin-right: 0.5rem;
}

.dashboard-header {
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    margin-bottom: 2rem;
}

.dashboard-header h1 {
    margin-bottom: 1rem;
}

.dashboard-nav {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.dashboard-nav a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 3px;
    transition: background 0.3s;
}

.dashboard-nav a:hover,
.dashboard-nav a.active {
    background: rgba(255, 255, 255, 0.2);
}

.dashboard-content {
    padding: 0 2rem 2rem;
}

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

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    text-align: center;
}

.stat-card h3 {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: bold;
    color: #2c3e50;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.course-card {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s;
}

.course-card:hover {
    transform: translateY(-2px);
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.course-header h3 {
    margin: 0;
    color: #2c3e50;
}

.course-duration {
    background: #e74c3c;
    color: white;
    padding: 0.2rem 0.5rem;
    border-radius: 3px;
    font-size: 0.8rem;
}

.course-description {
    color: #666;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.progress-section {
    margin-bottom: 1rem;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #ecf0f1;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: #27ae60;
    transition: width 0.3s;
}

.progress-text {
    font-size: 0.9rem;
    color: #666;
}

.course-meta {
    margin-bottom: 1rem;
}

.course-meta p {
    font-size: 0.8rem;
    color: #999;
    margin-bottom: 0.2rem;
}

.course-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-primary {
    background: #3498db;
    color: white;
    padding: 0.5rem 1rem;
    text-decoration: none;
    border-radius: 3px;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
}

.btn-secondary {
    background: #95a5a6;
    color: white;
    padding: 0.5rem 1rem;
    text-decoration: none;
    border-radius: 3px;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
}

.btn-success {
    background: #27ae60;
    color: white;
    padding: 0.5rem 1rem;
    text-decoration: none;
    border-radius: 3px;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
}

.filters-section {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.filters-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.search-box {
    display: flex;
    gap: 0.5rem;
}

.search-box input {
    flex: 1;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 3px;
}

.search-box button {
    background: #3498db;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 3px;
    cursor: pointer;
}

.filter-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    background: #ecf0f1;
    color: #666;
    padding: 0.5rem 1rem;
    text-decoration: none;
    border-radius: 3px;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
}

.filter-btn.active {
    background: #3498db;
    color: white;
}

.empty-state {
    text-align: center;
    padding: 3rem;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.empty-state h3 {
    color: #666;
    margin-bottom: 1rem;
}

.empty-state p {
    color: #999;
    margin-bottom: 1.5rem;
}

.study-container {
    min-height: 100vh;
    background: #f8f9fa;
}

.study-header {
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.study-nav {
    display: flex;
    gap: 1rem;
}

.study-content {
    display: flex;
    min-height: calc(100vh - 80px);
}

.lessons-sidebar {
    width: 300px;
    background: white;
    border-right: 1px solid #ddd;
    padding: 1rem;
}

.lessons-sidebar h3 {
    margin-bottom: 1rem;
    color: #2c3e50;
}

.lessons-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.lesson-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem;
    text-decoration: none;
    color: #666;
    border-radius: 3px;
    transition: background 0.2s;
}

.lesson-item:hover {
    background: #f8f9fa;
}

.lesson-item.active {
    background: #3498db;
    color: white;
}

.lesson-item.completed {
    color: #27ae60;
}

.lesson-number {
    background: #ecf0f1;
    color: #666;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: bold;
}

.lesson-item.active .lesson-number {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.lesson-item.completed .lesson-number {
    background: #27ae60;
    color: white;
}

.lesson-check {
    margin-left: auto;
    color: #27ae60;
    font-weight: bold;
}

.lesson-content {
    flex: 1;
    padding: 2rem;
}

.lesson-header {
    margin-bottom: 2rem;
}

.lesson-header h2 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.progress-indicator {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.progress-indicator span {
    font-size: 0.9rem;
    color: #666;
}

.lesson-body {
    margin-bottom: 2rem;
}

.h5p-container,
.video-container {
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.text-content {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    line-height: 1.6;
}

.lesson-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.certificate-card {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    border-left: 4px solid #27ae60;
}

.certificate-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.certificate-header h3 {
    margin: 0;
    color: #2c3e50;
}

.certificate-number {
    background: #ecf0f1;
    color: #666;
    padding: 0.2rem 0.5rem;
    border-radius: 3px;
    font-size: 0.8rem;
    font-family: monospace;
}

.certificate-info {
    margin-bottom: 1rem;
}

.certificate-info p {
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.status-valid {
    color: #27ae60;
    font-weight: bold;
}

.certificate-actions {
    display: flex;
    gap: 0.5rem;
}

.profile-sections {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.profile-info,
.change-password,
.account-info {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.profile-info h2,
.change-password h2,
.account-info h2 {
    color: #2c3e50;
    margin-bottom: 1.5rem;
}

.profile-form,
.password-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: bold;
    color: #2c3e50;
}

.form-group input {
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 3px;
    font-size: 1rem;
}

.form-group input:focus {
    outline: none;
    border-color: #3498db;
}

.form-group small {
    color: #999;
    font-size: 0.8rem;
}

.info-grid {
    display: grid;
    gap: 1rem;
}

.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid #ecf0f1;
}

.info-item:last-child {
    border-bottom: none;
}

.info-item label {
    font-weight: bold;
    color: #2c3e50;
}

.info-item span {
    color: #666;
}

.status-active {
    color: #27ae60;
    font-weight: bold;
}

.alert {
    padding: 1rem;
    border-radius: 3px;
    margin-bottom: 1rem;
}

.alert.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.admin-container {
    min-height: 100vh;
    background: #f5f5f5;
}

.admin-header {
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.admin-header h1 {
    margin: 0;
    font-size: 1.8rem;
}

.admin-nav {
    margin-top: 1rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.admin-nav a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background 0.3s;
}

.admin-nav a:hover,
.admin-nav a.active {
    background: rgba(255,255,255,0.1);
}

.admin-main {
    padding: 2rem;
}

.admin-actions {
    margin-bottom: 2rem;
    padding: 1rem;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.search-form {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.search-form input,
.search-form select {
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

.search-form button {
    background: #007bff;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
}

.search-form button:hover {
    background: #0056b3;
}

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

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    text-align: center;
}

.stat-card h3 {
    margin: 0 0 0.5rem 0;
    color: #666;
    font-size: 14px;
    text-transform: uppercase;
}

.stat-number {
    font-size: 2rem;
    font-weight: bold;
    color: #2c3e50;
    margin: 0;
}

.admin-sections {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.recent-section {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.recent-section h2 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.2rem;
}

.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

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

table th {
    background: #f8f9fa;
    font-weight: 600;
    color: #495057;
}

table tr:hover {
    background: #f8f9fa;
}

.status-badge {
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
    text-transform: uppercase;
}

.status-pending {
    background: #fff3cd;
    color: #856404;
}

.status-active,
.status-approved {
    background: #d4edda;
    color: #155724;
}

.status-rejected {
    background: #f8d7da;
    color: #721c24;
}

.status-draft {
    background: #e2e3e5;
    color: #383d41;
}

.status-valid {
    background: #d4edda;
    color: #155724;
}

.actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.btn-small {
    padding: 0.25rem 0.5rem;
    font-size: 12px;
    border-radius: 4px;
    text-decoration: none;
    color: white;
    border: none;
    cursor: pointer;
}

.btn-success {
    background: #28a745;
}

.btn-success:hover {
    background: #218838;
}

.btn-primary {
    background: #007bff;
}

.btn-primary:hover {
    background: #0056b3;
}

.btn-info {
    background: #17a2b8;
}

.btn-info:hover {
    background: #138496;
}

.btn-warning {
    background: #ffc107;
    color: #212529;
}

.btn-warning:hover {
    background: #e0a800;
}

.btn-danger {
    background: #dc3545;
}

.btn-danger:hover {
    background: #c82333;
}

.reports-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.report-section {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.report-section h2 {
    margin: 0 0 1rem 0;
    color: #2c3e50;
    font-size: 1.2rem;
}

.chart-container {
    overflow-x: auto;
}

.period-form {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.period-form select {
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

.verify-form {
    max-width: 500px;
    margin: 0 auto 2rem auto;
    padding: 2rem;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.certificate-verification {
    max-width: 600px;
    margin: 0 auto;
    padding: 2rem;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.certificate-details {
    margin: 1.5rem 0;
}

.detail-row {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid #eee;
}

.detail-row:last-child {
    border-bottom: none;
}

.certificate-code {
    font-family: monospace;
    font-weight: bold;
    color: #007bff;
}

.verification-status {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 8px;
}

.verification-status p {
    margin: 1rem 0 0 0;
    color: #666;
}

@media (max-width: 768px) {
    .dashboard-nav {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .study-content {
        flex-direction: column;
    }
    
    .lessons-sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid #ddd;
    }
    
    .lesson-navigation {
        flex-direction: column;
        gap: 1rem;
    }
    
    .profile-sections {
        grid-template-columns: 1fr;
    }
}