body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8f9fa;
}

.sidebar {
    min-height: 100vh;
    background: linear-gradient(180deg, #6f42c1 0%, #5a32a3 100%);
    box-shadow: 2px 0 10px rgba(0,0,0,.1);
}

.sidebar .nav-link {
    color: rgba(255, 255, 255, 0.8);
    padding: 1rem;
    border-radius: 8px;
    margin: 0.25rem 0.5rem;
    transition: all 0.3s ease;
}

.sidebar .nav-link:hover {
    color: #fff;
    background-color: rgba(255, 255, 255, 0.1);
    transform: translateX(5px);
}

.sidebar .nav-link.active {
    color: #fff;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0.2) 0%, rgba(255, 255, 255, 0.1) 100%);
    border-left: 4px solid #fff;
}

.sidebar .nav-link i {
    margin-right: 0.5rem;
    font-size: 1.1rem;
}

.dashboard-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 6px rgba(0,0,0,.1);
    padding: 1.5rem;
    margin-bottom: 2rem;
    border-radius: 10px;
}

.dashboard-header h2 {
    margin-bottom: 0;
    font-weight: 600;
}

.dashboard-header p {
    margin-bottom: 0;
    opacity: 0.9;
}

.stat-card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0,0,0,.1);
    transition: all 0.3s ease;
    overflow: hidden;
    position: relative;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--card-color-1) 0%, var(--card-color-2) 100%);
}

.stat-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(0,0,0,.15);
}

.stat-card.primary {
    --card-color-1: #667eea;
    --card-color-2: #764ba2;
}

.stat-card.success {
    --card-color-1: #56ab2f;
    --card-color-2: #a8e063;
}

.stat-card.warning {
    --card-color-1: #f093fb;
    --card-color-2: #f5576c;
}

.stat-card.danger {
    --card-color-1: #fa709a;
    --card-color-2: #fee140;
}

.stat-card.info {
    --card-color-1: #4facfe;
    --card-color-2: #00f2fe;
}

.stat-card .card-body {
    padding: 1.5rem;
}

.stat-card h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-top: 0.5rem;
    background: linear-gradient(135deg, var(--card-color-1) 0%, var(--card-color-2) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main-content {
    padding: 2rem;
    background-color: transparent;
}

.card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,.08);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: 0 4px 20px rgba(0,0,0,.12);
}

.card-header {
    border: none;
    border-radius: 12px 12px 0 0 !important;
    font-weight: 600;
}

.table-actions button {
    margin-right: 0.25rem;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.table-actions button:hover {
    transform: scale(1.1);
}

.btn {
    border-radius: 8px;
    padding: 0.5rem 1.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,.15);
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
}

.btn-success {
    background: linear-gradient(135deg, #56ab2f 0%, #a8e063 100%);
    border: none;
}

.btn-info {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    border: none;
}

.btn-warning {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    border: none;
}

.btn-danger {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    border: none;
}

.video-player {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
}

.material-card {
    transition: all 0.3s ease;
    border: none;
    border-radius: 12px;
    overflow: hidden;
}

.material-card:hover {
    box-shadow: 0 8px 20px rgba(0,0,0,.15);
    transform: translateY(-5px);
}

.subscription-badge {
    font-size: 0.875rem;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 500;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

.badge {
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 500;
}

.table {
    border-radius: 10px;
    overflow: hidden;
}

.table thead th {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.5px;
}

.table tbody tr {
    transition: all 0.2s ease;
}

.table tbody tr:hover {
    background-color: rgba(102, 126, 234, 0.05);
    transform: scale(1.01);
}

.modal-content {
    border: none;
    border-radius: 15px;
    overflow: hidden;
}

.modal-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
}

.form-control, .form-select {
    border-radius: 8px;
    border: 2px solid #e9ecef;
    transition: all 0.3s ease;
}

.form-control:focus, .form-select:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.stat-card, .card {
    animation: fadeIn 0.5s ease-out;
}

/* Mobile Navigation */
.mobile-nav-toggle {
    display: none;
    position: fixed;
    top: 15px;
    left: 15px;
    z-index: 1050;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    color: white;
    font-size: 1.5rem;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    transition: all 0.3s ease;
}

.mobile-nav-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.mobile-nav-toggle:focus {
    outline: none;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar-overlay.show {
    display: block;
    opacity: 1;
}

/* Progress Bar Styles */
.progress-circle {
    position: relative;
    width: 80px;
    height: 80px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.progress-circle svg {
    transform: rotate(-90deg);
}

.progress-circle .progress-value {
    position: absolute;
    font-weight: bold;
    font-size: 1rem;
}

.progress-animated {
    transition: stroke-dashoffset 1s ease-in-out;
}

.learning-progress-card {
    border: none;
    border-radius: 15px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.learning-progress-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,.15);
}

.progress-bar-gradient {
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
}

.notification-badge {
    position: absolute;
    top: -5px;
    right: -5px;
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    border-radius: 50%;
    width: 20px;
    height: 20px;
    font-size: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
}

/* Settings Toggle Switch */
.form-switch .form-check-input {
    width: 50px;
    height: 25px;
    cursor: pointer;
}

.form-switch .form-check-input:checked {
    background-color: #667eea;
    border-color: #667eea;
}

/* Responsive improvements */
@media (max-width: 768px) {
    .mobile-nav-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    .sidebar {
        position: fixed;
        z-index: 1000;
        width: 280px;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        top: 0;
        left: 0;
        height: 100vh;
        overflow-y: auto;
    }
    
    .sidebar.show {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0 !important;
        padding-top: 80px !important;
    }
    
    .dashboard-header {
        margin-top: 0;
    }
    
    .stat-card h2 {
        font-size: 1.8rem;
    }
    
    .table-responsive {
        font-size: 0.875rem;
    }
    
    .btn {
        padding: 0.4rem 1rem;
        font-size: 0.875rem;
    }
}

@media (max-width: 576px) {
    .stat-card .card-body {
        padding: 1rem;
    }
    
    .stat-card h2 {
        font-size: 1.5rem;
    }
    
    .card-header h5 {
        font-size: 1rem;
    }
    
    .dashboard-header h2 {
        font-size: 1.5rem;
    }
}