/* ========================================
   STUDENT MANAGEMENT - MODERN UI
   ======================================== */

/* Page Header */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem;
    border-radius: 16px;
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.3);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-info h1 {
    font-size: 2rem;
    margin: 0 0 0.5rem 0;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-info h1 i {
    font-size: 2.5rem;
}

.page-subtitle {
    margin: 0;
    opacity: 1;
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.95);
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
    font-weight: 500;
}

/* Statistics Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    border-radius: 16px;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, #667eea, #764ba2);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

.stat-icon-wrapper {
    flex-shrink: 0;
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
}

.bg-primary-light {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.bg-success-light {
    background: linear-gradient(135deg, #11998e, #38ef7d);
}

.bg-warning-light {
    background: linear-gradient(135deg, #f093fb, #f5576c);
}

.stat-content {
    flex: 1;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: #2d3748;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.875rem;
    color: #718096;
    margin-bottom: 0.5rem;
}

.stat-trend {
    font-size: 0.75rem;
    color: #a0aec0;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.stat-trend.text-success {
    color: #38a169;
}

/* Content Card */
.content-card {
    background: white;
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

/* Filters Section */
.filters-section {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.search-container {
    flex: 1;
}

.search-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 1rem;
    color: #a0aec0;
    font-size: 1rem;
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 0.875rem 3rem 0.875rem 3rem;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #f7fafc;
}

.search-input:focus {
    outline: none;
    border-color: #667eea;
    background: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-clear {
    position: absolute;
    right: 1rem;
    background: none;
    border: none;
    color: #a0aec0;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.3s ease;
}

.search-clear:hover {
    background: #edf2f7;
    color: #4a5568;
}

.search-hints {
    margin-top: 0.5rem;
    padding-left: 0.5rem;
}

.filter-container {
    display: flex;
    gap: 1rem;
    align-items: flex-end;
    flex-wrap: wrap;
}

.filter-form {
    flex: 1;
    min-width: 200px;
}

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

.filter-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: #4a5568;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.filter-select {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1rem;
    background: #f7fafc;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-select:focus {
    outline: none;
    border-color: #667eea;
    background: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

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

/* Content Section */
.content-section {
    margin-bottom: 2rem;
}

.results-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.view-toggle {
    display: flex;
    gap: 0.5rem;
}

.view-btn {
    padding: 0.5rem 0.75rem;
    border: 2px solid #e2e8f0;
    background: white;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
    color: #718096;
}

.view-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.view-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

/* Students Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.cards-grid.list-view {
    grid-template-columns: 1fr;
}

.cards-grid.list-view .student-card {
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: 1.5rem;
}

/* Student Card */
.student-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.student-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
}

.student-card .card-header {
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, #f7fafc, #edf2f7);
    border-bottom: 1px solid #e2e8f0;
}

.student-avatar {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea, #764ba2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
    position: relative;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.student-avatar.online {
    box-shadow: 0 4px 12px rgba(56, 161, 105, 0.3);
}

.status-indicator {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #38a169;
    border: 3px solid white;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.status-badge.online {
    background: #c6f6d5;
    color: #22543d;
}

.status-badge.offline {
    background: #fed7d7;
    color: #742a2a;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: currentColor;
}

.student-card .card-content {
    padding: 1.5rem;
    flex: 1;
}

.student-name {
    font-size: 1.125rem;
    font-weight: 700;
    color: #2d3748;
    margin: 0 0 1rem 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.student-details {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.875rem;
    color: #718096;
}

.detail-item i {
    width: 20px;
    color: #667eea;
}

.email-text {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.student-card .card-actions {
    padding: 1rem 1.5rem;
    display: flex;
    gap: 0.5rem;
    border-top: 1px solid #e2e8f0;
    background: #f7fafc;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.empty-icon {
    font-size: 4rem;
    color: #cbd5e0;
    margin-bottom: 1.5rem;
}

.empty-state h3 {
    font-size: 1.5rem;
    color: #2d3748;
    margin-bottom: 0.5rem;
}

.empty-state p {
    color: #718096;
    margin-bottom: 1.5rem;
}

/* Pagination */
.pagination-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    margin-top: 2rem;
}

.pagination-info {
    font-size: 0.875rem;
    color: #718096;
}

.pagination {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.page-link {
    padding: 0.5rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    background: white;
    color: #4a5568;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    min-width: 40px;
    text-align: center;
}

.page-link:hover {
    border-color: #667eea;
    color: #667eea;
    transform: translateY(-2px);
}

.page-link.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.page-ellipsis {
    padding: 0.5rem;
    color: #a0aec0;
}

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 9999;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.modal-container {
    width: 100%;
    max-width: 800px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-content {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    padding: 1.5rem 2rem;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.modal-icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.modal-title h2 {
    margin: 0;
    font-size: 1.5rem;
}

.modal-title p {
    margin: 0.25rem 0 0 0;
    opacity: 0.9;
    font-size: 0.875rem;
}

.modal-close {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: rotate(90deg);
}

.modal-form {
    padding: 2rem;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
}

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

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: #4a5568;
}

.required {
    color: #e53e3e;
}

.input-group {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 1rem;
    color: #a0aec0;
    pointer-events: none;
    z-index: 1;
}

.form-control {
    width: 100%;
    padding: 0.875rem 1rem 0.875rem 3rem;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #f7fafc;
}

.textarea-group .form-control {
    padding-left: 3rem;
    resize: vertical;
    min-height: 100px;
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
    background: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-hint {
    font-size: 0.75rem;
    color: #a0aec0;
}

.modal-footer {
    padding-top: 1.5rem;
    border-top: 1px solid #e2e8f0;
}

.modal-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #e2e8f0;
    color: #4a5568;
}

.btn-secondary:hover {
    background: #cbd5e0;
}

.btn-danger {
    background: linear-gradient(135deg, #f56565, #c53030);
    color: white;
    box-shadow: 0 4px 12px rgba(245, 101, 101, 0.3);
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(245, 101, 101, 0.4);
}

.btn-outline {
    background: white;
    color: #667eea;
    border: 2px solid #667eea;
}

.btn-outline:hover {
    background: #667eea;
    color: white;
}

.btn-outline-primary {
    background: white;
    color: #667eea;
    border: 2px solid #667eea;
}

.btn-outline-primary:hover {
    background: #667eea;
    color: white;
}

.btn-outline-secondary {
    background: white;
    color: #718096;
    border: 2px solid #e2e8f0;
}

.btn-outline-secondary:hover {
    background: #f7fafc;
    border-color: #cbd5e0;
}

.btn-outline-danger {
    background: white;
    color: #e53e3e;
    border: 2px solid #e53e3e;
}

.btn-outline-danger:hover {
    background: #e53e3e;
    color: white;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99999;
}

.loading-spinner {
    text-align: center;
    color: white;
}

.spinner {
    width: 60px;
    height: 60px;
    border: 5px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Flash Message */
.flash-message {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    z-index: 9999;
    animation: slideInRight 0.3s ease;
}

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

.flash-success {
    background: #c6f6d5;
    color: #22543d;
    border-left: 4px solid #38a169;
}

.flash-error {
    background: #fed7d7;
    color: #742a2a;
    border-left: 4px solid #e53e3e;
}

.flash-info {
    background: #bee3f8;
    color: #2c5282;
    border-left: 4px solid #3182ce;
}

/* Responsive */
@media (max-width: 768px) {
    .page-header {
        padding: 1.5rem;
    }
    
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }
    
    .header-info h1 {
        font-size: 1.5rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .filters-section {
        flex-direction: column;
    }
    
    .filter-container {
        flex-direction: column;
        align-items: stretch;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 1rem;
    }
    
    .modal-header {
        padding: 1rem;
    }
    
    .modal-form {
        padding: 1rem;
    }
    
    .modal-actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .stat-card {
        padding: 1rem;
    }
    
    .stat-icon {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .student-card .card-actions {
        flex-direction: column;
    }
    
    .student-card .card-actions .btn {
        width: 100%;
    }
}

/* Dark Mode Support */
[data-theme="dark"] .stat-card,
[data-theme="dark"] .content-card,
[data-theme="dark"] .student-card,
[data-theme="dark"] .modal-content,
[data-theme="dark"] .results-info,
[data-theme="dark"] .empty-state {
    background: #2d3748;
    color: #e2e8f0;
}

[data-theme="dark"] .search-input,
[data-theme="dark"] .filter-select,
[data-theme="dark"] .form-control {
    background: #1a202c;
    border-color: #4a5568;
    color: #e2e8f0;
}

[data-theme="dark"] .student-card .card-header {
    background: linear-gradient(135deg, #2d3748, #1a202c);
    border-bottom-color: #4a5568;
}

[data-theme="dark"] .student-card .card-actions {
    background: #1a202c;
    border-top-color: #4a5568;
}

[data-theme="dark"] .btn-outline,
[data-theme="dark"] .btn-outline-primary,
[data-theme="dark"] .btn-outline-secondary,
[data-theme="dark"] .btn-outline-danger {
    background: #2d3748;
}

[data-theme="dark"] .page-link {
    background: #2d3748;
    border-color: #4a5568;
    color: #e2e8f0;
}

[data-theme="dark"] .view-btn {
    background: #2d3748;
    border-color: #4a5568;
    color: #e2e8f0;
}