:root {
    --primary: #1e40af;
    --secondary: #3730a3;
    --accent: #059669;
    --success: #16a34a;
    --danger: #dc2626;
    --warning: #d97706;
    --info: #0284c7;
    --dark: #0f172a;
    --light: #f8fafc;
    --glass: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.12);
    --shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --gradient-1: linear-gradient(135deg, #1e3a8a 0%, #3730a3 50%, #1e40af 100%);
    --gradient-2: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
    --gradient-3: linear-gradient(135deg, #0284c7 0%, #0ea5e9 100%);
    --gradient-4: linear-gradient(135deg, #059669 0%, #16a34a 100%);
    --gradient-5: linear-gradient(135deg, #d97706 0%, #f59e0b 100%);
}

/* Theme 2 - Professional Dark */
.theme-2 {
    --primary: #2563eb;
    --secondary: #475569;
    --accent: #0891b2;
    --success: #059669;
    --danger: #dc2626;
    --warning: #d97706;
    --info: #0284c7;
    --dark: #1e293b;
    --light: #f1f5f9;
    --glass: rgba(30, 41, 59, 0.95);
    --glass-border: rgba(148, 163, 184, 0.2);
    --shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --gradient-1: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    --gradient-2: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    --gradient-3: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    --gradient-4: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --gradient-5: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
}

.theme-2 body {
    background: var(--gradient-1);
    color: var(--text-primary);
}

.theme-2 .card {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow);
}

.theme-2 .card:hover {
    transform: translateY(-6px);
    box-shadow: 0 25px 50px -5px rgba(0, 0, 0, 0.8);
    border-color: rgba(148, 163, 184, 0.4);
}

.theme-2 .form-input {
    background: rgba(30, 41, 59, 0.8);
    border: 2px solid rgba(148, 163, 184, 0.3);
    color: var(--text-primary);
    backdrop-filter: blur(10px);
}

.theme-2 .form-input:focus {
    border-color: var(--accent);
    background: rgba(30, 41, 59, 0.9);
    box-shadow: 0 0 0 3px rgba(8, 145, 178, 0.2);
}

.theme-2 .form-input::placeholder {
    color: var(--text-secondary);
}

.theme-2 .header h1 {
    background: linear-gradient(135deg, #f8fafc, #e2e8f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(248, 250, 252, 0.3);
}

.theme-2 .btn {
    backdrop-filter: blur(20px);
    border: 1px solid rgba(148, 163, 184, 0.2);
}

.theme-2 .btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

.theme-2 .nav-tab.active {
    background: var(--gradient-4);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
}

.theme-2 .student-avatar {
    background: var(--gradient-3);
    box-shadow: 0 4px 20px rgba(14, 165, 233, 0.4);
    border: 2px solid rgba(148, 163, 184, 0.2);
}

.theme-2 .assessment-card.active {
    border-color: var(--accent);
    background: rgba(8, 145, 178, 0.2);
    box-shadow: 0 8px 25px rgba(8, 145, 178, 0.3);
}

.theme-2 .student-card:hover {
    background: rgba(8, 145, 178, 0.15);
    transform: translateY(-4px);
    border-color: var(--accent);
    box-shadow: 0 8px 25px rgba(8, 145, 178, 0.3);
}

.theme-2 .assessment-card:hover {
    background: rgba(37, 99, 235, 0.15);
    transform: translateY(-6px);
    border-color: var(--primary);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.3);
}

.theme-2 .nav-tabs {
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(148, 163, 184, 0.2);
}

.theme-2 .table-container {
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(148, 163, 184, 0.2);
}

.theme-2 .folder-status {
    background: rgba(8, 145, 178, 0.2);
    border: 2px solid var(--accent);
    backdrop-filter: blur(15px);
}

.theme-2 .notification {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(148, 163, 184, 0.3);
}

.theme-2 .modal-content {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(148, 163, 184, 0.3);
}

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

body {
    font-family: 'Inter', 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--gradient-1);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    transition: all 0.3s ease;
}

/* PWA Mode - Hide Header/Footer */
@media (display-mode: standalone) {
    .site-header,
    .site-footer {
        display: none !important;
    }
    
    .container {
        padding-top: 10px;
    }
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header and Footer Styles */
.site-header {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 12px 0;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 16px;
}

.header-logo {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(5, 150, 105, 0.3);
}

.brand-text {
    display: flex;
    flex-direction: column;
}

.brand-title {
    font-size: 1.8rem;
    font-weight: 800;
    margin: 0;
    background: var(--gradient-4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.brand-subtitle {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.header-nav ul {
    display: flex;
    list-style: none;
    gap: 32px;
    margin: 0;
    padding: 0;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--accent);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.install-btn {
    background: var(--gradient-4);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.install-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(5, 150, 105, 0.4);
}

/* Page Header (replacing original header) */
.page-header {
    text-align: center;
    padding: 30px 0;
    margin-bottom: 20px;
}

.page-header h2 {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #ffffff, #e2e8f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 12px;
}

.page-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin: 0;
}

/* Footer Styles */
.site-footer {
    background: var(--dark);
    color: var(--text-primary);
    margin-top: 60px;
    border-top: 1px solid var(--glass-border);
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 48px 20px 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 48px;
    margin-bottom: 40px;
}

.footer-section h3,
.footer-section h4 {
    color: var(--accent);
    margin-bottom: 20px;
    font-weight: 700;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-logo {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(5, 150, 105, 0.3);
}

.footer-brand h3 {
    font-size: 1.8rem;
    margin: 0;
}

.footer-brand p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-section li {
    margin-bottom: 12px;
}

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
}

.footer-section a:hover {
    color: var(--accent);
}

.contact-info p {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
    color: var(--text-secondary);
}

.contact-info i {
    color: var(--accent);
    width: 16px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 24px;
    border-top: 1px solid var(--glass-border);
}

.footer-info p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Theme Selection Styles */
.theme-selection {
    display: flex;
    gap: 16px;
    margin-bottom: 16px;
}

.theme-option {
    flex: 1;
    padding: 20px;
    border-radius: 16px;
    border: 2px solid var(--glass-border);
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.theme-option:hover {
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.theme-option.active {
    border-color: var(--accent);
    background: rgba(5, 150, 105, 0.2);
    box-shadow: 0 4px 15px rgba(5, 150, 105, 0.3);
}

.theme-preview {
    width: 60px;
    height: 40px;
    border-radius: 8px;
    margin: 0 auto 12px;
    position: relative;
    overflow: hidden;
}

.theme-1-preview {
    background: linear-gradient(135deg, #1e3a8a 0%, #059669 100%);
}

.theme-2-preview {
    background: linear-gradient(135deg, #1e293b 0%, #0891b2 100%);
}

.theme-label {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.theme-sublabel {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* PWA Install Banner */
.install-banner {
    position: fixed;
    bottom: 20px;
    left: 20px;
    right: 20px;
    background: var(--glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
    z-index: 1000;
    max-width: 500px;
    margin: 0 auto;
    box-shadow: var(--shadow);
}

.install-banner-content {
    display: flex;
    align-items: center;
    gap: 16px;
}

.install-banner-icon img {
    width: 48px;
    height: 48px;
    border-radius: 12px;
}

.install-banner-text {
    flex: 1;
}

.install-banner-text h4 {
    margin: 0 0 4px 0;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.install-banner-text p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.install-banner-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.btn-link {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.85rem;
    padding: 4px 8px;
    text-decoration: underline;
}

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

/* Settings Button */
.settings-btn {
    background: var(--gradient-4);
    color: white;
    border: none;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(5, 150, 105, 0.3);
}

.settings-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(5, 150, 105, 0.4);
}

/* Cards */
.card {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 32px;
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow);
    margin-bottom: 24px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 32px 64px -12px rgba(0, 0, 0, 0.4);
}

/* Buttons */
.btn {
    background: var(--gradient-3);
    color: white;
    border: none;
    padding: 16px 32px;
    border-radius: 16px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    position: relative;
    overflow: hidden;
    margin: 6px;
    box-shadow: 0 4px 15px rgba(2, 132, 199, 0.3);
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(2, 132, 199, 0.4);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-primary { background: var(--gradient-1); box-shadow: 0 4px 15px rgba(30, 64, 175, 0.3); }
.btn-success { background: var(--gradient-4); box-shadow: 0 4px 15px rgba(5, 150, 105, 0.3); }
.btn-danger { background: var(--gradient-2); box-shadow: 0 4px 15px rgba(220, 38, 38, 0.3); }
.btn-warning { background: var(--gradient-5); box-shadow: 0 4px 15px rgba(217, 119, 6, 0.3); }
.btn-info { background: var(--gradient-3); }

/* Forms */
.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    margin-bottom: 10px;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.form-input {
    width: 100%;
    padding: 18px 24px;
    border-radius: 16px;
    border: 2px solid transparent;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.form-input:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.15);
    transform: scale(1.02);
}

.form-input::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

/* Checkbox */
.checkbox-group {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.checkbox-group:hover {
    background: rgba(255, 255, 255, 0.1);
}

.checkbox-group input[type="checkbox"], 
.checkbox-group input[type="radio"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

/* Navigation */
.nav-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    padding: 8px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 20px;
    backdrop-filter: blur(10px);
}

.nav-tab {
    background: transparent;
    border: none;
    padding: 16px 28px;
    border-radius: 16px;
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    flex: 1;
    text-align: center;
}

.nav-tab.active {
    background: var(--gradient-4);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(5, 150, 105, 0.3);
}

/* Grid */
.grid {
    display: grid;
    gap: 24px;
    margin-top: 24px;
}

.grid-cols-1 { grid-template-columns: 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-auto { grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }

/* Student Cards */
.student-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    position: relative;
}

.student-card:hover {
    background: rgba(5, 150, 105, 0.15);
    transform: translateY(-4px);
    border-color: var(--accent);
    box-shadow: 0 8px 25px rgba(5, 150, 105, 0.3);
}

.student-avatar {
    width: 68px;
    height: 68px;
    border-radius: 50%;
    background: var(--gradient-3);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.6rem;
    color: white;
    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.3);
}

/* Assessment Cards */
.assessment-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 28px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    text-align: center;
}

.assessment-card:hover {
    background: rgba(5, 150, 105, 0.15);
    transform: translateY(-6px);
    border-color: var(--accent);
    box-shadow: 0 8px 25px rgba(5, 150, 105, 0.3);
}

.assessment-card.active {
    border-color: var(--success);
    background: rgba(22, 163, 74, 0.2);
    box-shadow: 0 8px 25px rgba(22, 163, 74, 0.3);
}

/* Statistics */
.stat-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 32px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid var(--glass-border);
}

.stat-card:hover {
    transform: translateY(-6px);
    background: rgba(255, 255, 255, 0.15);
    box-shadow: 0 8px 25px rgba(255, 255, 255, 0.1);
}

.stat-value {
    font-size: 3.5rem;
    font-weight: 900;
    margin: 16px 0;
    line-height: 1;
}

.stat-label {
    font-size: 0.95rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

/* Status Colors */
.status-pass { color: #16a34a; }
.status-fail { color: #dc2626; }
.status-absent { color: #d97706; }
.status-null { color: var(--text-secondary); }

/* Table */
.table-container {
    overflow-x: auto;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
}

.table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}

.table th,
.table td {
    padding: 20px 24px;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.table th {
    background: rgba(255, 255, 255, 0.1);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.table tr:hover td {
    background: rgba(255, 255, 255, 0.08);
}

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

/* Marks Input */
.marks-input {
    width: 95px;
    padding: 12px 16px;
    border-radius: 12px;
    border: 2px solid transparent;
    background: rgba(255, 255, 255, 0.15);
    color: white;
    text-align: center;
    font-weight: 600;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.marks-input:focus {
    outline: none;
    border-color: var(--accent);
    transform: scale(1.05);
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.2);
}

.marks-input.pass {
    border-color: #16a34a;
    background: rgba(22, 163, 74, 0.2);
}

.marks-input.absent {
    border-color: #d97706;
    background: rgba(217, 119, 6, 0.2);
}

.marks-input.fail {
    border-color: #dc2626;
    background: rgba(220, 38, 38, 0.2);
}

/* Search */
.search-container {
    position: relative;
    margin-bottom: 24px;
}

.search-input {
    width: 100%;
    padding: 20px 28px 20px 64px;
    border-radius: 20px;
    border: 2px solid transparent;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.search-input:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.15);
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.2);
}

.search-input::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

.search-icon {
    position: absolute;
    left: 28px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 1.3rem;
}

/* Notifications */
.notification {
    position: fixed;
    top: 24px;
    right: 24px;
    background: var(--glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px 32px;
    color: white;
    display: flex;
    align-items: center;
    gap: 12px;
    transform: translateX(400px);
    opacity: 0;
    transition: all 0.5s ease;
    z-index: 1000;
    box-shadow: var(--shadow);
    max-width: 400px;
}

.notification.show {
    transform: translateX(0);
    opacity: 1;
}

.notification.success {
    border-left: 4px solid #16a34a;
}

.notification.error {
    border-left: 4px solid #dc2626;
}

.notification.warning {
    border-left: 4px solid #d97706;
}

.notification.info {
    border-left: 4px solid #0284c7;
}

/* Modals */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    backdrop-filter: blur(8px);
}

.modal-content {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border-radius: 28px;
    padding: 48px;
    max-width: 700px;
    width: 90%;
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow);
    text-align: center;
    max-height: 90vh;
    overflow-y: auto;
}

.modal h3 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--text-primary);
    background: var(--gradient-4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modal p {
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.6;
    font-size: 1.1rem;
}

.modal-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Folder Status */
.folder-status {
    background: rgba(5, 150, 105, 0.2);
    border: 2px solid var(--accent);
    border-radius: 16px;
    padding: 20px;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    backdrop-filter: blur(10px);
}

.folder-status.error {
    background: rgba(220, 38, 38, 0.2);
    border-color: var(--danger);
}

/* Export Options */
.export-options {
    text-align: left;
    margin: 24px 0;
}

.export-section {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid var(--glass-border);
}

.export-section h4 {
    color: var(--accent);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Register Number Status */
.register-status {
    background: rgba(5, 150, 105, 0.2);
    border: 2px solid var(--success);
    border-radius: 12px;
    padding: 16px;
    margin-top: 12px;
    border-left: 4px solid var(--success);
}

/* Assessment Info */
.assessment-info {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 16px;
    border-left: 4px solid var(--info);
}

/* Section Content */
.section-content {
    animation: fadeIn 0.3s ease-in-out;
}

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

/* Loading state */
.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid var(--accent);
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Performance optimizations */
.card, .btn, .nav-tab {
    will-change: transform;
}

/* Utility Classes */
.hidden { display: none !important; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.mb-4 { margin-bottom: 24px; }
.mt-4 { margin-top: 24px; }
.ml-4 { margin-left: 24px; }
.mr-4 { margin-right: 24px; }
.p-4 { padding: 24px; }
.pb-4 { padding-bottom: 24px; }
.pt-4 { padding-top: 24px; }
.pl-4 { padding-left: 24px; }
.pr-4 { padding-right: 24px; }

/* Screen reader only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Print styles */
@media print {
    .settings-btn,
    .btn,
    .nav-tabs,
    .notification {
        display: none !important;
    }
    
    .card {
        background: white !important;
        color: black !important;
        box-shadow: none !important;
    }
    
    .table th,
    .table td {
        border: 1px solid #000 !important;
    }
}

/* Responsive Design for Header and Footer */
@media (max-width: 768px) {
    .header-container {
        flex-wrap: wrap;
        gap: 16px;
    }
    
    .header-nav {
        order: 3;
        width: 100%;
    }
    
    .nav-menu {
        justify-content: center;
        gap: 20px;
    }
    
    .brand-title {
        font-size: 1.5rem;
    }
    
    .page-header h2 {
        font-size: 2rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
        text-align: center;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
    
    .contact-info p {
        justify-content: center;
    }
    
    .install-banner {
        left: 16px;
        right: 16px;
        padding: 16px;
    }
    
    .install-banner-content {
        flex-direction: column;
        text-align: center;
    }
    
    .install-banner-actions {
        flex-direction: row;
        justify-content: center;
    }
    
    .theme-selection {
        flex-direction: column;
    }
}

@media (max-width: 1200px) {
    .grid-auto { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
}

@media (max-width: 768px) {
    .container { 
        padding: 16px; 
    }
    
    .page-header h2 { 
        font-size: 2rem; 
    }
    
    .page-header {
        padding: 20px 0;
    }
    
    .grid-cols-2, 
    .grid-cols-3, 
    .grid-cols-4 { 
        grid-template-columns: 1fr; 
    }
    
    .nav-tabs { 
        flex-direction: column;
        gap: 4px;
    }
    
    .nav-tab {
        padding: 12px 16px;
    }
    
    .marks-input { 
        width: 75px; 
    }
    
    .modal-buttons { 
        flex-direction: column; 
    }
    
    .modal-content {
        padding: 32px 24px;
        width: 95%;
    }
    
    .card {
        padding: 20px;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 0.9rem;
    }
    
    .student-card {
        padding: 16px;
        gap: 16px;
    }
    
    .student-avatar {
        width: 56px;
        height: 56px;
        font-size: 1.4rem;
    }
    
    .assessment-card {
        padding: 20px;
    }
    
    .stat-card {
        padding: 24px;
    }
    
    .stat-value {
        font-size: 2.5rem;
    }
    
    .form-input {
        padding: 16px 20px;
    }
    
    .search-input {
        padding: 16px 24px 16px 56px;
    }
    
    .search-icon {
        left: 20px;
    }
    
    .table th,
    .table td {
        padding: 16px 12px;
    }
}

@media (max-width: 480px) {
    .page-header h2 { 
        font-size: 1.8rem; 
    }
    
    .card { 
        padding: 16px; 
    }
    
    .btn { 
        padding: 12px 20px; 
        font-size: 0.85rem; 
    }
    
    .modal-content {
        padding: 24px 16px;
    }
    
    .stat-value {
        font-size: 2rem;
    }
    
    .marks-input {
        width: 65px;
        padding: 10px 12px;
    }
    
    .form-input {
        padding: 14px 16px;
        font-size: 1rem;
    }
    
    .search-input {
        padding: 14px 20px 14px 48px;
        font-size: 1rem;
    }
    
    .search-icon {
        left: 16px;
        font-size: 1.1rem;
    }
    
    .student-avatar {
        width: 48px;
        height: 48px;
        font-size: 1.2rem;
    }
    
    .notification {
        right: 16px;
        top: 16px;
        padding: 16px 24px;
        max-width: calc(100vw - 32px);
    }
    
    .settings-btn {
        width: 40px;
        height: 40px;
        font-size: 0.9rem;
    }
    
    .folder-status {
        padding: 16px;
    }
    
    .header-container {
        padding: 0 16px;
    }
    
    .nav-menu {
        gap: 16px;
        font-size: 0.9rem;
    }
    
    .brand-title {
        font-size: 1.3rem;
    }
    
    .footer-container {
        padding: 32px 16px 20px;
    }
    
    .footer-brand {
        gap: 12px;
    }
    
    .footer-logo {
        width: 48px;
        height: 48px;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --glass: rgba(255, 255, 255, 0.15);
        --glass-border: rgba(255, 255, 255, 0.3);
        --text-secondary: #e2e8f0;
    }
    
    .card {
        border: 2px solid var(--glass-border);
    }
    
    .btn {
        border: 2px solid rgba(255, 255, 255, 0.3);
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .card:hover,
    .btn:hover,
    .student-card:hover,
    .assessment-card:hover {
        transform: none;
    }
}

/* Smooth scrolling for anchor links */
html {
    scroll-behavior: smooth;
}

/* Focus styles for accessibility */
.nav-link:focus,
.footer-section a:focus,
.social-links a:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-radius: 4px;
}

/* Ensure keyboard focus visibility on interactive elements */
button:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.3);
}

/* Hide visually but keep accessible for screen-readers */
.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}