/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --secondary-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

/* Navigation */
.navbar {
    background-color: var(--card-bg);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 1.5rem;
}

.nav-menu {
    display: flex;
    gap: 0.5rem;
}

.nav-link {
    padding: 0.5rem 1rem;
    text-decoration: none;
    color: var(--text-secondary);
    border-radius: 0.5rem;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link:hover {
    background-color: var(--bg-color);
    color: var(--primary-color);
}

.nav-link.active {
    background-color: var(--primary-color);
    color: white;
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.nav-user i {
    font-size: 1.5rem;
}

/* Main Content */
.main-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

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

.page-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    color: var(--text-secondary);
}

.page-actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

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

.stat-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 0.75rem;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
}

.stat-icon.courses {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.stat-icon.students {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.stat-icon.teachers {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.stat-icon.enrollments {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.stat-content h3 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.stat-content p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Content Section */
.content-section {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 0.75rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.content-section h2 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

/* Table */
.table-container {
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table thead {
    background-color: var(--bg-color);
}

.data-table th {
    padding: 0.75rem 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.data-table td {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

.data-table tbody tr:hover {
    background-color: var(--bg-color);
}

.data-table .loading {
    text-align: center;
    color: var(--text-secondary);
    padding: 2rem;
}

/* Buttons */
.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
}

.btn-secondary {
    background-color: var(--text-secondary);
    color: white;
}

.btn-secondary:hover {
    background-color: var(--text-primary);
}

.btn-success {
    background-color: var(--secondary-color);
    color: white;
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
}

.btn-sm {
    padding: 0.25rem 0.75rem;
    font-size: 0.875rem;
}

/* Forms */
.search-input,
.form-input,
.form-select {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.search-input:focus,
.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.search-input {
    min-width: 300px;
}

/* Report Filters */
.report-filters {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

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

.filter-group label {
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Report Results */
.report-results {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.report-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

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

.report-content {
    background: var(--bg-color);
    padding: 1.5rem;
    border-radius: 0.5rem;
}

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

.report-stat {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 0.5rem;
    border-left: 4px solid var(--primary-color);
}

.report-stat h4 {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.report-stat p {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    background: var(--card-bg);
    padding: 1rem 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: 300px;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.toast.success {
    border-left: 4px solid var(--secondary-color);
}

.toast.error {
    border-left: 4px solid var(--danger-color);
}

.toast.info {
    border-left: 4px solid var(--info-color);
}

.toast.warning {
    border-left: 4px solid var(--warning-color);
}

/* Badge */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-primary {
    background-color: #dbeafe;
    color: #1e40af;
}

.badge-success {
    background-color: #d1fae5;
    color: #065f46;
}

.badge-warning {
    background-color: #fef3c7;
    color: #92400e;
}

.badge-info {
    background-color: #e0e7ff;
    color: #3730a3;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .page-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .search-input {
        min-width: 100%;
    }

    .report-filters {
        grid-template-columns: 1fr;
    }

    .report-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
}

/* Tabs */
.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: -2px;
}

.tab-btn:hover {
    color: var(--primary-color);
    background-color: var(--bg-color);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
}

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

/* Section Header */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.section-header h2 {
    margin: 0;
}

/* Code styling */
code {
    background-color: var(--bg-color);
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    color: var(--primary-color);
}

/* Detail page specific styles */
.page-header .btn {
    margin-bottom: 1rem;
}

/* Responsive tabs */
@media (max-width: 768px) {
    .tabs {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .tab-btn {
        white-space: nowrap;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .section-header .search-input {
        width: 100%;
    }
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    animation: fadeIn 0.2s ease-out;
}

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

.modal-content {
    background: var(--card-bg);
    border-radius: 0.75rem;
    box-shadow: var(--shadow-lg);
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.25rem;
    transition: all 0.2s;
}

.modal-close:hover {
    background-color: var(--bg-color);
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
    overflow-y: auto;
    flex: 1;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem;
}

/* Courses by Term */
.courses-by-term {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.term-section {
    background: var(--bg-color);
    padding: 1rem;
    border-radius: 0.5rem;
}

.term-section h3 {
    margin: 0 0 0.75rem 0;
    font-size: 1.125rem;
    color: var(--primary-color);
}

.course-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.course-list li {
    padding: 0.5rem;
    background: var(--card-bg);
    border-radius: 0.25rem;
    border-left: 3px solid var(--primary-color);
}

.course-link {
    color: var(--text-primary);
    text-decoration: none;
    display: block;
    transition: color 0.2s;
}

.course-link:hover {
    color: var(--primary-color);
}

/* Responsive modal */
@media (max-width: 768px) {
    .modal-content {
        width: 95%;
        max-height: 90vh;
    }

    .modal-header,
    .modal-body,
    .modal-footer {
        padding: 1rem;
    }
}