/* ============================================
   VARIABLES & BASE STYLES
============================================ */
:root {
    /* Color Palette */
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --gray-color: #95a5a6;
    --border-color: #ddd;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Typography */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-xxl: 2rem;
    
    /* Border Radius */
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.1);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #f8f9fa;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

/* ============================================
   TYPOGRAPHY
============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

h1 { font-size: var(--font-size-xxl); }
h2 { font-size: var(--font-size-xl); }
h3 { font-size: var(--font-size-lg); }
h4 { font-size: var(--font-size-md); }

p {
    margin-bottom: var(--spacing-sm);
}

a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: #2980b9;
}

/* ============================================
   UTILITY CLASSES
============================================ */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.d-none { display: none !important; }
.d-block { display: block !important; }
.d-flex { display: flex; }
.d-grid { display: grid; }

.flex-column { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }

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

.m-0 { margin: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }

.p-0 { padding: 0; }
.p-1 { padding: var(--spacing-xs); }
.p-2 { padding: var(--spacing-sm); }
.p-3 { padding: var(--spacing-md); }

.rounded { border-radius: var(--border-radius-md); }
.shadow { box-shadow: var(--shadow-md); }

/* ============================================
   FORMS
============================================ */
.form-container {
    max-width: 600px;
    margin: var(--spacing-xl) auto;
    padding: var(--spacing-lg);
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--dark-color);
}

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

.form-control:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.form-control.error {
    border-color: var(--danger-color);
    box-shadow: 0 0 0 3px rgba(231, 76, 60, 0.2);
}

.form-row {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

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

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.radio-group {
    display: flex;
    gap: var(--spacing-md);
}

.radio-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

/* ============================================
   BUTTONS
============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: var(--font-size-md);
    font-weight: 500;
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    white-space: nowrap;
}

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

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

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

.btn-primary:hover {
    background-color: #2980b9;
}

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

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

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

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

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: var(--font-size-sm);
}

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

.btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-disabled:hover {
    transform: none;
    box-shadow: none;
}

/* ============================================
   ALERTS & MESSAGES
============================================ */
.alert {
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    margin-bottom: var(--spacing-sm);
    border-left: 4px solid transparent;
}

.alert-success {
    background-color: #d4edda;
    border-color: var(--success-color);
    color: #155724;
}

.alert-error {
    background-color: #f8d7da;
    border-color: var(--danger-color);
    color: #721c24;
}

.alert-warning {
    background-color: #fff3cd;
    border-color: var(--warning-color);
    color: #856404;
}

.alert-info {
    background-color: #d1ecf1;
    border-color: var(--secondary-color);
    color: #0c5460;
}

/* ============================================
   NAVIGATION
============================================ */
header {
    background-color: white;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
}

.logo {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    margin: 0;
    padding: 0;
}

.nav-links a {
    color: var(--dark-color);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.nav-links a:hover {
    background-color: var(--light-color);
    color: var(--secondary-color);
}

.nav-links a.active {
    background-color: var(--secondary-color);
    color: white;
}

.auth-buttons {
    display: flex;
    gap: var(--spacing-xs);
}

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

/* ============================================
   HERO SECTION
============================================ */
.hero {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.hero h1 {
    font-size: var(--font-size-xxl);
    color: white;
    margin-bottom: var(--spacing-sm);
}

.hero p {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
}

/* ============================================
   CARDS
============================================ */
.card {
    background: white;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--spacing-sm);
}

.card-title {
    margin: 0;
    color: var(--primary-color);
}

.card-body {
    padding: var(--spacing-sm) 0;
}

.card-footer {
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
    margin-top: var(--spacing-sm);
}

/* Dashboard Cards */
.dashboard-cards {
    display: grid;
    gap: var(--spacing-md);
    margin: var(--spacing-lg) 0;
}

.card-stat {
    text-align: center;
    padding: var(--spacing-lg);
}

.card-stat .number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin: var(--spacing-xs) 0;
}

.card-stat .label {
    color: var(--gray-color);
    font-size: var(--font-size-sm);
}

/* Program Cards */
.program-card {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.program-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
}

.program-type {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: var(--font-size-xs);
    font-weight: 600;
}

.program-type.free {
    background: #d4edda;
    color: #155724;
}

.program-type.paid {
    background: #fff3cd;
    color: #856404;
}

.program-dates {
    margin: var(--spacing-sm) 0;
    font-size: var(--font-size-sm);
}

.program-description {
    flex-grow: 1;
    margin-bottom: var(--spacing-sm);
}

.course-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: var(--spacing-sm) 0;
}

.course-tag {
    background: #e9ecef;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: var(--font-size-xs);
}

.program-actions {
    display: flex;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

/* ============================================
   TABLES
============================================ */
.table-container {
    overflow-x: auto;
    margin: var(--spacing-lg) 0;
    background: white;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

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

th, td {
    padding: var(--spacing-sm);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: var(--font-size-sm);
}

tbody tr:hover {
    background-color: #f8f9fa;
}

/* Badges in tables */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
}

.badge-admin {
    background-color: #e3f2fd;
    color: #1976d2;
}

.badge-learner {
    background-color: #e8f5e9;
    color: #388e3c;
}

.badge-pending {
    background-color: #fff3e0;
    color: #f57c00;
}

.badge-approved {
    background-color: #e8f5e9;
    color: #388e3c;
}

.badge-rejected {
    background-color: #ffebee;
    color: #d32f2f;
}

/* ============================================
   SIDEBAR LAYOUT (Admin)
============================================ */
.sidebar-layout {
    display: flex;
    min-height: calc(100vh - 70px);
}

.sidebar {
    width: 250px;
    background: var(--primary-color);
    color: white;
    position: sticky;
    top: 70px;
    height: calc(100vh - 70px);
    overflow-y: auto;
}

.sidebar-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-menu {
    list-style: none;
    padding: var(--spacing-sm) 0;
}

.sidebar-menu li {
    margin: 0;
}

.sidebar-menu a {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.sidebar-menu a:hover {
    background: rgba(255,255,255,0.1);
    color: white;
}

.sidebar-menu a.active {
    background: var(--secondary-color);
    color: white;
}

.sidebar-menu i {
    width: 20px;
    text-align: center;
}

.main-content {
    flex: 1;
    padding: var(--spacing-lg);
    background: #f8f9fa;
    overflow-y: auto;
}

.main-header {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-sm);
}

/* ============================================
   PROFILE STYLES
============================================ */
.profile-container {
    background: white;
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.profile-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: var(--light-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: var(--secondary-color);
}

.profile-info h2 {
    margin: 0 0 var(--spacing-xs) 0;
}

.profile-info p {
    margin: 0.25rem 0;
    color: var(--gray-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ============================================
   GRID SYSTEMS
============================================ */
.program-grid {
    display: grid;
    gap: var(--spacing-md);
}

.stats-grid {
    display: grid;
    gap: var(--spacing-md);
}

.features-grid {
    display: grid;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl) 0;
}

.feature-card {
    text-align: center;
    padding: var(--spacing-lg);
}

.feature-card i {
    font-size: 3rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-sm);
}

/* ============================================
   EMPTY STATES
============================================ */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--gray-color);
}

.empty-state i {
    font-size: 4rem;
    color: #dee2e6;
    margin-bottom: var(--spacing-md);
}

.empty-state h3 {
    color: var(--gray-color);
    margin-bottom: var(--spacing-xs);
}

/* ============================================
   FORM VALIDATION STYLES
============================================ */
.field-error {
    color: var(--danger-color);
    font-size: var(--font-size-sm);
    margin-top: 0.25rem;
    display: block;
}

.form-summary-error {
    margin-bottom: var(--spacing-md);
}

/* ============================================
   LOADING STATES
============================================ */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-xl);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--light-color);
    border-top-color: var(--secondary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ============================================
   MODALS & POPUPS
============================================ */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    padding: var(--spacing-sm);
}

.modal-dialog {
    background: white;
    border-radius: var(--border-radius-lg);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

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

.modal-body {
    padding: var(--spacing-md);
}

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

/* ============================================
   FOOTER
============================================ */
footer {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-lg) 0;
    margin-top: auto;
}

.footer-content {
    display: grid;
    gap: var(--spacing-lg);
}

.footer-links {
    display: grid;
    gap: var(--spacing-md);
}

.footer-links a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
}

.footer-links a:hover {
    color: white;
}

.copyright {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.6);
    font-size: var(--font-size-sm);
}

/* ============================================
   MOBILE FIRST APPROACH
============================================ */

/* Extra small devices (phones, 320px and up) */
@media (min-width: 320px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
}

/* Small devices (phones, 576px and down) */
@media (max-width: 576px) {
    .navbar {
        flex-direction: column;
        padding: var(--spacing-sm);
        gap: var(--spacing-sm);
    }
    
    .nav-links {
        flex-direction: column;
        gap: 0;
        margin: var(--spacing-sm) 0;
        width: 100%;
        text-align: center;
    }
    
    .nav-links li {
        width: 100%;
    }
    
    .nav-links a {
        display: block;
        padding: 0.75rem 1rem;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-links a:last-child {
        border-bottom: none;
    }
    
    .auth-buttons {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
        gap: var(--spacing-xs);
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .cta-buttons .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .sidebar-layout {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        position: static;
        height: auto;
        padding: 0;
    }
    
    .sidebar-header {
        padding: var(--spacing-sm);
    }
    
    .sidebar-menu {
        display: flex;
        overflow-x: auto;
        padding: 0;
        gap: 0;
    }
    
    .sidebar-menu li {
        flex: 0 0 auto;
    }
    
    .sidebar-menu li a {
        padding: var(--spacing-sm);
        border-bottom: 3px solid transparent;
        border-left: none;
        white-space: nowrap;
    }
    
    .sidebar-menu li a.active {
        border-bottom: 3px solid var(--secondary-color);
        border-left: none;
    }
    
    .main-content {
        padding: var(--spacing-md);
    }
    
    .main-header {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: stretch;
        text-align: center;
    }
    
    .profile-header {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-md);
    }
    
    .avatar {
        margin: 0 auto;
    }
    
    /* Table Responsiveness */
    table {
        display: block;
        min-width: 100%;
    }
    
    thead {
        display: none;
    }
    
    tbody tr {
        display: block;
        margin-bottom: var(--spacing-md);
        border: 1px solid var(--border-color);
        border-radius: var(--border-radius-md);
        padding: var(--spacing-sm);
    }
    
    tbody td {
        display: block;
        text-align: right;
        padding-left: 50%;
        position: relative;
        border-bottom: 1px solid var(--border-color);
        padding: var(--spacing-xs) var(--spacing-sm);
    }
    
    tbody td:last-child {
        border-bottom: none;
    }
    
    tbody td::before {
        content: attr(data-label);
        position: absolute;
        left: var(--spacing-sm);
        width: calc(50% - var(--spacing-md));
        padding-right: var(--spacing-sm);
        text-align: left;
        font-weight: 600;
        color: var(--dark-color);
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
    
    .program-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .form-container {
        padding: var(--spacing-md);
        margin: var(--spacing-md) auto;
    }
    
    .form-row {
        flex-direction: column;
    }
    
    .form-row .form-group {
        width: 100%;
    }
    
    .radio-group {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .modal-dialog {
        margin: var(--spacing-xs);
    }
    
    .btn-group {
        flex-direction: column;
        width: 100%;
    }
    
    .btn-group .btn {
        width: 100%;
    }
}

/* Medium devices (tablets, 577px to 768px) */
@media (min-width: 577px) and (max-width: 768px) {
    .nav-links {
        gap: var(--spacing-sm);
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .program-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .dashboard-cards {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .form-row {
        flex-direction: row;
    }
    
    .form-row .form-group {
        flex: 1;
    }
    
    .sidebar-menu {
        flex-wrap: wrap;
    }
    
    .sidebar-menu li {
        flex: 1 0 auto;
    }
}

/* Large devices (desktops, 769px to 992px) */
@media (min-width: 769px) and (max-width: 992px) {
    .program-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .dashboard-cards {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
}

/* Extra large devices (large desktops, 993px and up) */
@media (min-width: 993px) {
    .program-grid {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .dashboard-cards {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .features-grid {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .container {
        padding: 0 var(--spacing-lg);
    }
}

/* Extra large devices (1200px and up) */
@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }
}

/* Navigation Toggle for Mobile */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-sm);
        flex-direction: column;
        gap: 0;
        z-index: 1000;
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .navbar {
        position: relative;
    }
}

/* Form responsiveness */
@media (max-width: 576px) {
    .form-row {
        flex-direction: column;
    }
    
    .form-row .form-group {
        width: 100%;
    }
    
    .modal-dialog {
        margin: var(--spacing-xs);
    }
}

/* Card deck responsiveness */
.card-deck {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

/* Utility classes for responsive text */
.text-sm-center {
    text-align: center;
}

@media (max-width: 576px) {
    .text-sm-center {
        text-align: center;
    }
    
    .d-sm-block {
        display: block !important;
    }
    
    .d-sm-none {
        display: none !important;
    }
    
    .d-sm-flex {
        display: flex !important;
    }
}

@media (min-width: 577px) {
    .d-md-block {
        display: block !important;
    }
    
    .d-md-none {
        display: none !important;
    }
}

/* Print styles */
@media print {
    .no-print {
        display: none !important;
    }
    
    .sidebar {
        display: none;
    }
    
    .main-content {
        width: 100%;
        padding: 0;
    }
    
    .navbar,
    .footer {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
    
    .btn {
        display: none;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #000080;
        --secondary-color: #0000ff;
        --border-color: #000000;
    }
    
    .btn {
        border: 2px solid var(--border-color);
    }
    
    .form-control {
        border: 2px solid var(--border-color);
    }
    
    .card {
        border: 2px solid var(--border-color);
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #1a1a2e;
        --secondary-color: #3498db;
        --light-color: #2c3e50;
        --dark-color: #ecf0f1;
        --border-color: #34495e;
    }
    
    body {
        background-color: #121212;
        color: #e0e0e0;
    }
    
    .card,
    .form-container,
    .table-container,
    .main-header,
    .profile-container {
        background-color: #1e1e1e;
        color: #e0e0e0;
    }
    
    .form-control {
        background-color: #2d2d2d;
        border-color: #444;
        color: #e0e0e0;
    }
    
    .nav-links a,
    .sidebar-menu a {
        color: #ccc;
    }
    
    .table-container th {
        background-color: #2c3e50;
    }
    
    .table-container tr:hover {
        background-color: #2d2d2d;
    }
}

/* Landscape orientation for mobile */
@media (max-width: 768px) and (orientation: landscape) {
    .hero {
        padding: var(--spacing-md) 0;
    }
    
    .hero h1 {
        font-size: 1.5rem;
    }
    
    .hero p {
        font-size: 0.9rem;
    }
    
    .sidebar-menu {
        flex-wrap: nowrap;
        overflow-x: auto;
    }
}

/* Very small screens (320px and below) */
@media (max-width: 320px) {
    :root {
        --spacing-sm: 0.75rem;
        --spacing-md: 1rem;
        --spacing-lg: 1.5rem;
    }
    
    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
    
    .form-container {
        padding: var(--spacing-sm);
    }
    
    .card {
        padding: var(--spacing-sm);
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .btn {
        min-height: 44px;
        min-width: 44px;
    }
    
    .nav-links a {
        min-height: 44px;
        display: flex;
        align-items: center;
    }
    
    .form-control {
        min-height: 44px;
    }
    
    .menu-toggle {
        min-height: 44px;
        min-width: 44px;
    }
}