/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f6fa;
    color: #2d3436;
}

.container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Styles */
.sidebar {
    width: 250px;
    background-color: #2c3e50;
    color: white;
    padding: 20px;
    position: fixed;
    height: 100vh;
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
}

.logo {
    text-align: center;
    margin-bottom: 30px;
}

.logo img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 10px;
    border: 3px solid #3498db;
}

.logo h2 {
    color: #ecf0f1;
    font-size: 24px;
    font-weight: 600;
}

.nav-links {
    list-style: none;
}

.nav-links li {
    margin-bottom: 10px;
}

.nav-links a {
    color: #ecf0f1;
    text-decoration: none;
    display: flex;
    align-items: center;
    padding: 12px 15px;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 16px;
}

.nav-links a i {
    margin-right: 12px;
    width: 20px;
    font-size: 18px;
}

.nav-links li.active a {
    background-color: #3498db;
    color: white;
}

.nav-links a:hover {
    background-color: #34495e;
    transform: translateX(5px);
}

/* Main Content Styles */
.main-content {
    flex: 1;
    margin-left: 250px;
    padding: 20px;
}

/* Top Bar Styles */
.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 25px;
    background-color: white;
    border-radius: 15px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 30px;
}

.greeting {
    flex: 1;
}

.greeting h2 {
    color: #2c3e50;
    font-size: 28px;
    margin-bottom: 15px;
}

.upcoming-tasks {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid #3498db;
}

.upcoming-tasks h3 {
    color: #2c3e50;
    font-size: 18px;
    margin-bottom: 15px;
}

.upcoming-tasks ul {
    list-style: none;
    margin-bottom: 20px;
}

.upcoming-tasks li {
    display: flex;
    align-items: center;
    margin-bottom: 12px;
    color: #34495e;
    font-size: 15px;
}

.upcoming-tasks li i {
    margin-right: 10px;
    color: #3498db;
}

.upcoming-tasks .quick-links {
    display: flex;
    gap: 15px;
    margin: 20px 0;
    padding-top: 15px;
    border-top: 1px solid #e9ecef;
}

.upcoming-tasks .quick-links .btn {
    flex: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 12px 20px;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.upcoming-tasks .quick-links .btn i {
    font-size: 18px;
    transition: transform 0.3s ease;
}

.upcoming-tasks .quick-links .btn.primary {
    background: linear-gradient(135deg, #3498db, #2980b9);
    color: white;
}

.upcoming-tasks .quick-links .btn.secondary {
    background: linear-gradient(135deg, #2ecc71, #27ae60);
    color: white;
}

.upcoming-tasks .quick-links .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.15);
}

.upcoming-tasks .quick-links .btn:hover i {
    transform: scale(1.1);
}

.upcoming-tasks .quick-links .btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.upcoming-tasks .course-info {
    background-color: white;
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
}

.upcoming-tasks .course-info h4 {
    color: #2c3e50;
    font-size: 16px;
    margin-bottom: 10px;
}

.upcoming-tasks .course-info p {
    color: #7f8c8d;
    font-size: 14px;
    line-height: 1.5;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 25px;
}

.notifications {
    font-size: 1.4em;
    color: #7f8c8d;
    cursor: pointer;
    transition: color 0.3s;
}

.notifications:hover {
    color: #3498db;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 15px;
    background-color: #f8f9fa;
    padding: 10px 20px;
    border-radius: 25px;
}

.user-profile img {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    border: 2px solid #3498db;
}

.user-profile span {
    color: #2c3e50;
    font-weight: 500;
}

.logout-btn {
    background-color: #e74c3c;
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 5px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background-color 0.3s;
}

.logout-btn:hover {
    background-color: #c0392b;
}

/* Course Content Styles */
.course-header {
    margin-bottom: 30px;
}

.course-header h1 {
    color: #2c3e50;
    margin-bottom: 10px;
}

.course-info {
    color: #7f8c8d;
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.module-card {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    overflow: hidden;
    transition: transform 0.3s;
    cursor: pointer;
}

.module-card:hover {
    transform: translateY(-5px);
}

.module-card.disabled {
    opacity: 0.7;
    cursor: not-allowed;
    pointer-events: none;
}

.module-card.disabled:hover {
    transform: none;
}

.module-header {
    padding: 20px;
    background-color: #3498db;
    color: white;
}

.module-header h3 {
    margin-bottom: 10px;
}

.progress {
    font-size: 0.9em;
    opacity: 0.9;
}

.module-content {
    padding: 20px;
}

.module-content ul {
    list-style: none;
}

.module-content li {
    padding: 10px 0;
    border-bottom: 1px solid #eee;
    display: flex;
    align-items: center;
    gap: 10px;
}

.module-content li:last-child {
    border-bottom: none;
}

.module-content i {
    color: #3498db;
    width: 20px;
}

/* Course Detail Styles */
.course-detail {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    padding: 20px;
    margin-top: 20px;
}

.detail-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid #eee;
}

.back-button {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: background-color 0.3s;
}

.back-button:hover {
    background-color: #2980b9;
}

.lesson-section, .assignment-section {
    margin-bottom: 30px;
}

.lesson-section h3, .assignment-section h3 {
    color: #2c3e50;
    margin-bottom: 20px;
}

.lesson-items, .assignment-items {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.lesson-item, .assignment-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.lesson-item:hover, .assignment-item:hover {
    background-color: #e9ecef;
}

.lesson-item i, .assignment-item i {
    color: #3498db;
    font-size: 1.2em;
}

.due-date {
    margin-left: auto;
    color: #7f8c8d;
    font-size: 0.9em;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        width: 70px;
        padding: 15px 10px;
    }

    .sidebar .logo h2,
    .nav-links a span {
        display: none;
    }

    .main-content {
        margin-left: 70px;
    }

    .top-bar {
        flex-direction: column;
        gap: 20px;
    }

    .user-profile span {
        display: none;
    }

    .upcoming-tasks .quick-links {
        flex-direction: column;
    }

    .upcoming-tasks .quick-links .btn {
        width: 100%;
        padding: 15px 20px;
    }
}

@media (max-width: 480px) {
    .top-bar {
        padding: 15px;
    }

    .greeting h2 {
        font-size: 24px;
    }

    .upcoming-tasks {
        padding: 15px;
    }

    .upcoming-tasks .quick-links {
        flex-direction: column;
    }

    .upcoming-tasks .quick-links .btn {
        width: 100%;
        padding: 15px 20px;
    }
}