/* Modern School Management System CSS Framework */

/* CSS Variables for Consistent Theming */
:root {
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #818cf8;
    --secondary-color: #06b6d4;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --dark-color: #1f2937;
    --light-color: #f9fafb;
    --gray-color: #6b7280;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--dark-color);
    line-height: 1.6;
}

/* Container and Layout */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1rem;
}

.container-fluid {
    width: 100%;
    padding: 0 1rem;
}

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

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
.grid-cols-5 { grid-template-columns: repeat(5, 1fr); }
.grid-cols-6 { grid-template-columns: repeat(6, 1fr); }

/* Flexbox Utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-start { justify-content: flex-start; }
.justify-end { justify-content: flex-end; }

.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }

/* Sidebar Navigation */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 280px;
    height: 100vh;
    background: white;
    box-shadow: var(--shadow-xl);
    z-index: 1000;
    transition: var(--transition);
    overflow-y: auto;
}

.sidebar.collapsed {
    width: 80px;
}

.sidebar-header {
    padding: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.sidebar-logo {
    width: 40px;
    height: 40px;
    background: white;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.sidebar-title {
    font-size: 1.25rem;
    font-weight: 700;
    transition: var(--transition);
}

.sidebar.collapsed .sidebar-title {
    opacity: 0;
    visibility: hidden;
}

.sidebar-nav {
    padding: 1rem 0;
}

.nav-item {
    display: block;
    padding: 0.875rem 1.5rem;
    color: var(--dark-color);
    text-decoration: none;
    transition: var(--transition);
    border-left: 3px solid transparent;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-item:hover {
    background: var(--light-color);
    border-left-color: var(--primary-color);
}

.nav-item.active {
    background: linear-gradient(90deg, rgba(79, 70, 229, 0.1) 0%, transparent 100%);
    border-left-color: var(--primary-color);
    color: var(--primary-color);
    font-weight: 600;
}

.nav-icon {
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
}

.nav-text {
    transition: var(--transition);
}

.sidebar.collapsed .nav-text {
    opacity: 0;
    visibility: hidden;
}

/* Main Content Area */
.main-content {
    margin-left: 280px;
    min-height: 100vh;
    background: var(--light-color);
    transition: var(--transition);
}

.main-content.expanded {
    margin-left: 80px;
}

/* Top Header */
.top-header {
    background: white;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.menu-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--dark-color);
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.menu-toggle:hover {
    background: var(--light-color);
}

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

.user-profile {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1rem;
    background: var(--light-color);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition);
}

.user-profile:hover {
    background: var(--border-color);
}

.user-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: var(--transition);
}

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

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(135deg, var(--light-color), white);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

.card-subtitle {
    color: var(--gray-color);
    font-size: 0.875rem;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    background: var(--light-color);
}

/* Statistics Cards */
.stat-card {
    background: white;
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.stat-card.primary::before { background: linear-gradient(90deg, var(--primary-color), var(--primary-light)); }
.stat-card.success::before { background: linear-gradient(90deg, var(--success-color), #34d399); }
.stat-card.warning::before { background: linear-gradient(90deg, var(--warning-color), #fbbf24); }
.stat-card.danger::before { background: linear-gradient(90deg, var(--danger-color), #f87171); }

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.stat-card.primary .stat-icon { background: rgba(79, 70, 229, 0.1); color: var(--primary-color); }
.stat-card.success .stat-icon { background: rgba(16, 185, 129, 0.1); color: var(--success-color); }
.stat-card.warning .stat-icon { background: rgba(245, 158, 11, 0.1); color: var(--warning-color); }
.stat-card.danger .stat-icon { background: rgba(239, 68, 68, 0.1); color: var(--danger-color); }

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--gray-color);
    font-size: 0.875rem;
    font-weight: 500;
}

.stat-change {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    margin-top: 0.5rem;
}

.stat-change.positive {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.stat-change.negative {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

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

.btn:active {
    transform: translateY(0);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.75rem;
}

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

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

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

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

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

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

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

.btn-warning:hover {
    background: #d97706;
}

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

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

.btn-outline {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--dark-color);
}

.btn-outline:hover {
    background: var(--light-color);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-ghost {
    background: transparent;
    color: var(--gray-color);
}

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

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--dark-color);
    font-size: 0.875rem;
}

.form-label .required {
    color: var(--danger-color);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    transition: var(--transition);
    background: white;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-control.is-invalid {
    border-color: var(--danger-color);
}

.form-control.is-valid {
    border-color: var(--success-color);
}

.form-text {
    font-size: 0.75rem;
    color: var(--gray-color);
    margin-top: 0.25rem;
}

.form-text.text-danger {
    color: var(--danger-color);
}

.form-text.text-success {
    color: var(--success-color);
}

select.form-control {
    cursor: pointer;
}

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

/* Tables */
.table-container {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}

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

.table th {
    background: var(--light-color);
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--dark-color);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 2px solid var(--border-color);
}

.table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
}

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

.table tbody tr:last-child td {
    border-bottom: none;
}

/* Alerts */
.alert {
    padding: 1rem 1.5rem;
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.alert-danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.alert-info {
    background: rgba(6, 182, 212, 0.1);
    color: var(--secondary-color);
    border: 1px solid rgba(6, 182, 212, 0.2);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-xl);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-primary {
    background: rgba(79, 70, 229, 0.1);
    color: var(--primary-color);
}

.badge-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.badge-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.badge-danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.badge-secondary {
    background: rgba(107, 114, 128, 0.1);
    color: var(--gray-color);
}

/* Progress Bars */
.progress {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-xl);
    transition: width 0.3s ease;
}

/* Loading States */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

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

/* Responsive Design */
@media (max-width: 1024px) {
    .sidebar {
        width: 80px;
    }
    
    .sidebar-title,
    .nav-text {
        opacity: 0;
        visibility: hidden;
    }
    
    .main-content {
        margin-left: 80px;
    }
    
    .grid-cols-4 { grid-template-columns: repeat(3, 1fr); }
    .grid-cols-5 { grid-template-columns: repeat(3, 1fr); }
    .grid-cols-6 { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        width: 280px;
    }
    
    .sidebar.mobile-open {
        transform: translateX(0);
    }
    
    .sidebar-title,
    .nav-text {
        opacity: 1;
        visibility: visible;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .grid-cols-2,
    .grid-cols-3,
    .grid-cols-4,
    .grid-cols-5,
    .grid-cols-6 {
        grid-template-columns: 1fr;
    }
    
    .header-content {
        padding: 1rem;
    }
    
    .stat-card {
        padding: 1rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .table-container {
        overflow-x: auto;
    }
    
    .btn {
        padding: 0.625rem 1.25rem;
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }
    
    .card-body {
        padding: 1rem;
    }
    
    .form-control {
        padding: 0.625rem 0.875rem;
    }
    
    .table th,
    .table td {
        padding: 0.75rem 0.5rem;
        font-size: 0.8rem;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--primary-color); }
.text-secondary { color: var(--secondary-color); }
.text-success { color: var(--success-color); }
.text-warning { color: var(--warning-color); }
.text-danger { color: var(--danger-color); }
.text-gray { color: var(--gray-color); }

.bg-primary { background: var(--primary-color); }
.bg-secondary { background: var(--secondary-color); }
.bg-success { background: var(--success-color); }
.bg-warning { background: var(--warning-color); }
.bg-danger { background: var(--danger-color); }
.bg-light { background: var(--light-color); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-5 { margin-bottom: 1.25rem; }
.mb-6 { margin-bottom: 1.5rem; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-5 { margin-top: 1.25rem; }
.mt-6 { margin-top: 1.5rem; }

.p-0 { padding: 0; }
.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 0.75rem; }
.p-4 { padding: 1rem; }
.p-5 { padding: 1.25rem; }
.p-6 { padding: 1.5rem; }

.hidden { display: none; }
.block { display: block; }
.inline { display: inline; }
.inline-block { display: inline-block; }

.w-full { width: 100%; }
.h-full { height: 100%; }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.transition { transition: var(--transition); }

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

@keyframes slideIn {
    from { transform: translateX(-100%); }
    to { transform: translateX(0); }
}

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

.animate-fade-in {
    animation: fadeIn 0.5s ease-out;
}

.animate-slide-in {
    animation: slideIn 0.3s ease-out;
}

.animate-pulse {
    animation: pulse 2s infinite;
}