/* Reset & Variables */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;

    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-sidebar: #1e293b;
    --bg-sidebar-hover: #334155;

    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --text-white: #ffffff;

    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);

    --sidebar-width: 280px;
    --sidebar-collapsed-width: 80px;
}

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

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

.hidden {
    display: none !important;
}

.active {
    display: block !important;
}

/* App Container */
.app-container {
    display: flex;
    min-height: 100vh;
    transition: all 0.3s ease;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, var(--bg-sidebar) 0%, #0f172a 100%);
    color: var(--text-white);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    left: 0;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-lg);
}

.sidebar.collapsed {
    width: var(--sidebar-collapsed-width);
}

.sidebar-header {
    padding: 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
}

.school-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-white);
}

.school-brand i {
    font-size: 2rem;
    color: var(--primary-color);
}

.school-brand h2 {
    font-size: 1.5rem;
    font-weight: 700;
    transition: opacity 0.3s;
}

.sidebar.collapsed .school-brand h2 {
    opacity: 0;
    width: 0;
    overflow: hidden;
}

.sidebar-nav {
    flex: 1;
    padding: 1rem 0;
    overflow-y: auto;
}

.nav-section {
    margin-bottom: 1.5rem;
}

.nav-section-title {
    padding: 0.5rem 1.5rem;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-light);
    font-weight: 600;
    transition: opacity 0.3s;
}

.sidebar.collapsed .nav-section-title {
    opacity: 0;
    height: 0;
    padding: 0;
}

.nav-item {
    display: flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    color: var(--text-light);
    text-decoration: none;
    transition: all 0.2s;
    cursor: pointer;
    gap: 0.75rem;
    border-left: 3px solid transparent;
}

.nav-item:hover {
    background-color: var(--bg-sidebar-hover);
    color: var(--text-white);
    border-left-color: var(--primary-color);
}

.nav-item.active {
    background-color: rgba(37, 99, 235, 0.2);
    color: var(--text-white);
    border-left-color: var(--primary-color);
}

.nav-item i {
    font-size: 1.25rem;
    min-width: 24px;
    text-align: center;
}

.nav-item span {
    transition: opacity 0.3s;
}

.sidebar.collapsed .nav-item span {
    opacity: 0;
    width: 0;
    overflow: hidden;
}

.sidebar-footer {
    padding: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border-radius: 0.5rem;
    background-color: rgba(255, 255, 255, 0.05);
}

.profile-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.1);
}

.profile-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-info {
    display: flex;
    flex-direction: column;
    flex: 1;
    transition: opacity 0.3s;
}

.sidebar.collapsed .profile-info {
    opacity: 0;
    width: 0;
    overflow: hidden;
}

.profile-name {
    font-weight: 600;
    font-size: 0.9rem;
}

.profile-role {
    font-size: 0.75rem;
    color: var(--text-light);
    text-transform: capitalize;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
    transition: margin-left 0.3s ease;
}

.app-container.sidebar-collapsed .main-content {
    margin-left: var(--sidebar-collapsed-width);
}

.content-header {
    background: var(--bg-secondary);
    padding: 1.25rem 2rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.sidebar-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 0.5rem;
    transition: all 0.2s;
}

.sidebar-toggle:hover {
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

.page-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.header-actions {
    display: flex;
    gap: 0.75rem;
}

/* Hide scrollbar for sidebar nav */
.sidebar-nav::-webkit-scrollbar {
    display: none;
}

.sidebar-nav {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

.notification-btn,
.message-btn {
    position: relative;
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.75rem;
    border-radius: 0.5rem;
    transition: all 0.2s;
}

.notification-btn:hover,
.message-btn:hover {
    background-color: var(--bg-primary);
    color: var(--primary-color);
}

.notification-badge,
.message-badge {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background-color: var(--danger-color);
    color: var(--text-white);
    border-radius: 50%;
    width: 1.25rem;
    height: 1.25rem;
    font-size: 0.7rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

/* Content Area */
.content-area {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
}

/* Cards */
.card {
    background: var(--bg-secondary);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: 1.5rem;
    transition: all 0.2s;
}

.card:hover {
    box-shadow: var(--shadow-md);
}

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

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-title i {
    color: var(--primary-color);
}

/* Buttons */
.btn {
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    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: var(--text-white);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background-color: #475569;
}

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

.btn-success:hover {
    background-color: #059669;
}

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

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

.btn-danger:hover {
    background-color: #dc2626;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.btn-icon {
    padding: 0.5rem;
    width: 2.5rem;
    height: 2.5rem;
    justify-content: center;
}

/* Grid */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

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

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

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background-color: var(--bg-primary);
    font-weight: 600;
    color: var(--text-primary);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
}

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

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

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

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

.badge-danger {
    background-color: #fee2e2;
    color: #991b1b;
}

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

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 0.9rem;
    transition: all 0.2s;
    font-family: inherit;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

/* Stats Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 0.75rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: all 0.2s;
}

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

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-icon {
    float: right;
    font-size: 2.5rem;
    opacity: 0.2;
    margin-top: -1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.mobile-open {
        transform: translateX(0);
    }

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

    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    .content-area {
        padding: 1rem;
    }

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

/* Loading Spinner */
.spinner {
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.3;
}

.empty-state h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.empty-state p {
    color: var(--text-secondary);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.3s ease;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    backdrop-filter: blur(4px);
}

.modal {
    background: var(--bg-secondary);
    border-radius: 0.75rem;
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: fadeIn 0.3s ease;
}

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

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 0.5rem;
    transition: all 0.2s;
}

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

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
}