/* CBT System - Modern Professional Stylesheet */

:root {
    --primary: #1e40af;
    --primary-dark: #1e3a8a;
    --primary-light: #3b82f6;
    --secondary: #3b82f6;
    --success: #10b981;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --danger: #ef4444;
    --danger-light: #fee2e2;
    --info: #06b6d4;
    --info-light: #cffafe;
    
    --bg-dark: #0f172a;
    --bg-darker: #020617;
    --bg-card: #1e293b;
    --bg-card-hover: #334155;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --text-dark: #1e293b;
    
    --border-color: rgba(255, 255, 255, 0.1);
    --border-light: #e2e8f0;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.25);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.4);
    
    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    --sidebar-width: 260px;
    --header-height: 64px;
    
    --transition: all 0.3s ease;
}

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

html, body {
    height: 100%;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 14px;
    line-height: 1.6;
    background: linear-gradient(135deg, var(--bg-darker) 0%, var(--bg-dark) 50%, #0f1729 100%);
    color: var(--text-primary);
    min-height: 100vh;
}

body.light-mode {
    background: var(--bg-light);
    color: var(--text-dark);
}

/* Modern Toast Notifications */
#toastContainer {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 99999;
    display: flex;
    flex-direction: column;
    gap: 12px;
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    min-width: 320px;
    max-width: 420px;
    padding: 18px 20px;
    border-radius: 14px;
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.05);
    pointer-events: auto;
    animation: toastSlideIn 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    overflow: hidden;
    position: relative;
}

.toast.toast-hiding {
    animation: toastSlideOut 0.3s cubic-bezier(0.4, 0, 1, 1) forwards;
}

.toast-icon {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    flex-shrink: 0;
}

.toast-success .toast-icon { background: rgba(16, 185, 129, 0.15); color: var(--success); }
.toast-error .toast-icon { background: rgba(239, 68, 68, 0.15); color: var(--danger); }
.toast-warning .toast-icon { background: rgba(245, 158, 11, 0.15); color: var(--warning); }
.toast-info .toast-icon { background: rgba(6, 182, 212, 0.15); color: var(--info); }

.toast-content {
    flex: 1;
    padding-right: 20px;
}

.toast-title {
    font-weight: 600;
    font-size: 15px;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.toast-message {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.toast-close {
    position: absolute;
    top: 12px;
    right: 12px;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    width: 26px;
    height: 26px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 16px;
    transition: all 0.2s;
}

.toast-close:hover {
    background: rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
}

.toast-progress {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    border-radius: 0 0 14px 14px;
    animation: toastProgress 5s linear forwards;
}

.toast-success .toast-progress { background: var(--success); }
.toast-error .toast-progress { background: var(--danger); }
.toast-warning .toast-progress { background: var(--warning); }
.toast-info .toast-progress { background: var(--info); }

@keyframes toastSlideIn {
    from {
        opacity: 0;
        transform: translateX(100%) scale(0.9);
    }
    to {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
}

@keyframes toastSlideOut {
    from {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
    to {
        opacity: 0;
        transform: translateX(100%) scale(0.9);
    }
}

@keyframes toastProgress {
    from { width: 100%; }
    to { width: 0%; }
}

/* Mobile responsive toasts */
@media (max-width: 480px) {
    #toastContainer {
        left: 12px;
        right: 12px;
        top: 12px;
    }
    .toast {
        min-width: auto;
        max-width: none;
    }
}

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Login Page */
.login-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: linear-gradient(135deg, var(--bg-darker) 0%, var(--bg-dark) 100%);
}

.login-container {
    width: 100%;
    max-width: 420px;
}

.login-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 40px;
    box-shadow: var(--shadow-xl);
}

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-logo {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-lg);
    object-fit: cover;
    border: 2px solid var(--border-color);
    margin-bottom: 16px;
}

.login-header h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 4px;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 14px;
}

.login-tabs {
    display: flex;
    background: var(--bg-darker);
    border-radius: var(--radius);
    padding: 4px;
    margin-bottom: 24px;
}

.login-tab {
    flex: 1;
    padding: 10px;
    text-align: center;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: var(--transition);
}

.login-tab.active {
    background: var(--primary);
    color: white;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--bg-darker);
    color: var(--text-primary);
    font-size: 14px;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.form-control::placeholder {
    color: var(--text-muted);
}

.input-icon-wrapper {
    position: relative;
}

.input-icon-wrapper .form-control {
    padding-left: 44px;
}

.input-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.btn-sm { padding: 8px 16px; font-size: 13px; }
.btn-lg { padding: 16px 32px; font-size: 16px; }

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-block {
    width: 100%;
}

/* Admin Layout */
.admin-wrapper {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-card);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    z-index: 100;
    transition: var(--transition);
}

.sidebar-header {
    padding: 24px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-logo {
    width: 60px;
    height: 60px;
    border-radius: var(--radius);
    object-fit: cover;
    margin-bottom: 12px;
}

.sidebar-header h2 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 4px;
}

.sidebar-subtitle {
    font-size: 12px;
    color: var(--text-muted);
}

.sidebar-nav {
    flex: 1;
    padding: 16px 0;
    overflow-y: auto;
}

.nav-section {
    padding: 12px 24px 8px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.nav-item:hover {
    background: var(--bg-card-hover);
    color: var(--text-primary);
}

.nav-item.active {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-light);
    border-left-color: var(--primary);
}

.nav-item i {
    width: 20px;
    text-align: center;
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid var(--border-color);
}

.nav-item.logout:hover {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 24px;
    min-height: 100vh;
}

/* Top Header */
.top-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.page-title {
    font-size: 24px;
    font-weight: 700;
}

.header-actions {
    display: flex;
    gap: 12px;
    align-items: center;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 16px;
    background: var(--bg-card);
    border-radius: var(--radius);
    cursor: pointer;
}

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

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    margin-bottom: 20px;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.card-title {
    font-size: 18px;
    font-weight: 600;
}

/* Stats Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: var(--transition);
}

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

.stat-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.stat-icon.blue { background: rgba(59, 130, 246, 0.2); color: var(--primary-light); }
.stat-icon.green { background: rgba(16, 185, 129, 0.2); color: var(--success); }
.stat-icon.orange { background: rgba(245, 158, 11, 0.2); color: var(--warning); }
.stat-icon.red { background: rgba(239, 68, 68, 0.2); color: var(--danger); }
.stat-icon.purple { background: rgba(139, 92, 246, 0.2); color: #8b5cf6; }

.stat-info h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 4px;
}

.stat-info p {
    color: var(--text-secondary);
    font-size: 14px;
}

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

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

.table th,
.table td {
    padding: 14px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    background: var(--bg-darker);
}

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

.table .actions {
    display: flex;
    gap: 8px;
}

.table .actions .btn {
    padding: 6px 12px;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.badge-success { background: var(--success-light); color: #065f46; }
.badge-warning { background: var(--warning-light); color: #92400e; }
.badge-danger { background: var(--danger-light); color: #991b1b; }
.badge-info { background: var(--info-light); color: #0e7490; }
.badge-primary { background: rgba(59, 130, 246, 0.2); color: var(--primary-light); }

/* Forms */
.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

select.form-control {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2394a3b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    padding-right: 40px;
}

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

.form-check {
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-check input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary);
}

.form-hint {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 4px;
}

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: var(--transition);
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    font-size: 18px;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 24px;
    cursor: pointer;
    padding: 4px;
}

.modal-body {
    padding: 24px;
}

.modal-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 12px;
}

/* Exam Taking Screen */
.exam-wrapper {
    min-height: 100vh;
    background: var(--bg-darker);
}

.exam-header {
    background: var(--bg-card);
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.exam-info h2 {
    font-size: 18px;
    margin-bottom: 4px;
}

.exam-info p {
    color: var(--text-secondary);
    font-size: 13px;
}

.exam-timer {
    background: var(--bg-darker);
    padding: 12px 24px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    gap: 12px;
}

.timer-value {
    font-size: 28px;
    font-weight: 700;
    font-family: monospace;
}

.timer-warning {
    color: var(--danger);
    animation: pulse 1s infinite;
}

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

.exam-body {
    display: flex;
    gap: 24px;
    padding: 24px;
    max-width: 1400px;
    margin: 0 auto;
}

.exam-main {
    flex: 1;
}

.exam-sidebar {
    width: 280px;
    flex-shrink: 0;
}

.question-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 32px;
    margin-bottom: 20px;
}

.question-number {
    color: var(--primary-light);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.question-text {
    font-size: 20px;
    font-weight: 600;
    line-height: 1.5;
    margin-bottom: 24px;
}

.options-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.option-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    background: var(--bg-darker);
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
}

.option-item:hover {
    border-color: var(--primary);
    background: rgba(59, 130, 246, 0.1);
}

.option-item.selected {
    border-color: var(--primary);
    background: rgba(59, 130, 246, 0.2);
}

.option-item.correct {
    border-color: var(--success);
    background: rgba(16, 185, 129, 0.2);
}

.option-item.wrong {
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.2);
}

.option-letter {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bg-card);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.option-text {
    flex: 1;
}

/* Question Navigator */
.question-navigator {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 20px;
    position: sticky;
    top: 100px;
}

.navigator-title {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-secondary);
}

.navigator-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

.nav-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: var(--bg-darker);
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.nav-btn:hover {
    border-color: var(--primary);
}

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

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

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

.navigator-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    color: var(--text-muted);
}

.legend-dot {
    width: 12px;
    height: 12px;
    border-radius: 3px;
}

.legend-dot.current { background: var(--primary); }
.legend-dot.answered { background: var(--success); }
.legend-dot.flagged { background: var(--warning); }
.legend-dot.unanswered { background: var(--bg-darker); border: 1px solid var(--border-color); }

/* Question Controls */
.question-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 24px;
}

.control-left,
.control-right {
    display: flex;
    gap: 12px;
}

/* Results Page */
.result-card {
    text-align: center;
    padding: 48px;
}

.result-icon {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin: 0 auto 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
}

.result-icon.pass {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.result-icon.fail {
    background: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

.result-score {
    font-size: 64px;
    font-weight: 800;
    margin-bottom: 8px;
}

.result-grade {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 24px;
}

.result-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    margin-top: 32px;
}

.result-stat {
    text-align: center;
}

.result-stat-value {
    font-size: 28px;
    font-weight: 700;
}

.result-stat-label {
    color: var(--text-muted);
    font-size: 14px;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 24px;
}

.page-btn {
    padding: 8px 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
}

.page-btn:hover,
.page-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 48px;
    color: var(--text-muted);
}

.empty-state i {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

/* Search & Filters */
.filters-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 20px;
}

.search-box {
    flex: 1;
    min-width: 250px;
    position: relative;
}

.search-box input {
    width: 100%;
    padding: 10px 16px 10px 44px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--bg-darker);
    color: var(--text-primary);
}

.search-box i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.filter-select {
    min-width: 160px;
}

/* File Upload */
.file-upload {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.file-upload:hover {
    border-color: var(--primary);
    background: rgba(59, 130, 246, 0.05);
}

.file-upload i {
    font-size: 48px;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.file-upload input {
    display: none;
}

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

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

.loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .exam-body {
        flex-direction: column;
    }
    
    .exam-sidebar {
        width: 100%;
        order: -1;
    }
    
    .question-navigator {
        position: static;
    }
}

@media (max-width: 768px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .login-card {
        padding: 24px;
    }
    
    .result-stats {
        flex-direction: column;
        gap: 24px;
    }
}

/* Print Styles */
@media print {
    .sidebar,
    .top-header,
    .btn,
    .no-print {
        display: none !important;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    body {
        background: white;
        color: black;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--text-muted); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-warning { color: var(--warning); }

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

.d-flex { display: flex; }
.gap-1 { gap: 8px; }
.gap-2 { gap: 16px; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }

.hidden { display: none !important; }

/* Notification System Styles */
.notification-badge {
    position: absolute;
    top: 5px;
    right: 20px;
    min-width: 18px;
    height: 18px;
    border-radius: 9px;
    background: var(--danger);
    color: white;
    font-size: 11px;
    font-weight: 600;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 0 5px;
}

.notification-dropdown {
    position: absolute;
    bottom: 50px;
    left: 0;
    width: 320px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    display: none;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.notification-dropdown.active {
    display: block;
}

.notification-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-darker);
}

.notification-list {
    max-height: 350px;
    overflow-y: auto;
}

.notification-item {
    display: flex;
    gap: 12px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: background 0.2s;
}

.notification-item:hover {
    background: var(--bg-darker);
}

.notification-item.unread {
    background: rgba(59, 130, 246, 0.1);
}

.notification-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.notification-icon.notification-info {
    background: rgba(59, 130, 246, 0.2);
    color: #3b82f6;
}

.notification-icon.notification-success {
    background: rgba(16, 185, 129, 0.2);
    color: #10b981;
}

.notification-icon.notification-warning {
    background: rgba(245, 158, 11, 0.2);
    color: #f59e0b;
}

.notification-icon.notification-error {
    background: rgba(239, 68, 68, 0.2);
    color: #ef4444;
}

.notification-content {
    flex: 1;
    min-width: 0;
}

.notification-title {
    font-weight: 600;
    font-size: 13px;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.notification-message {
    font-size: 12px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.notification-time {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 4px;
}

.notification-empty,
.notification-loading {
    padding: 30px;
    text-align: center;
    color: var(--text-muted);
}

.notification-empty i,
.notification-loading i {
    font-size: 32px;
    margin-bottom: 10px;
    opacity: 0.5;
}