/**
 * Secure Exam System - Premium Dark Theme
 * Modern, sleek design with glassmorphism and gradients
 */

/* === Font Import === */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

/* === CSS Variables - Dark Theme === */
:root {
    /* Dark color palette */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-glass: rgba(30, 41, 59, 0.8);

    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    --border-color: rgba(148, 163, 184, 0.2);
    --border-light: rgba(148, 163, 184, 0.1);

    /* Gradient colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --accent: #06b6d4;
    --accent-light: #22d3ee;

    --success: #10b981;
    --success-light: rgba(16, 185, 129, 0.15);
    --danger: #ef4444;
    --danger-light: rgba(239, 68, 68, 0.15);
    --warning: #f59e0b;
    --warning-light: rgba(245, 158, 11, 0.15);
    --info: #3b82f6;
    --info-light: rgba(59, 130, 246, 0.15);

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #06b6d4 100%);
    --gradient-success: linear-gradient(135deg, #10b981 0%, #06b6d4 100%);
    --gradient-danger: linear-gradient(135deg, #ef4444 0%, #f59e0b 100%);
    --gradient-bg: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);

    /* Glow effects */
    --glow-primary: rgba(99, 102, 241, 0.4);
    --glow-accent: rgba(6, 182, 212, 0.4);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-base: 16px;
    --font-size-lg: 18px;
    --font-size-xl: 24px;
    --font-size-xxl: 32px;
    --font-size-sm: 14px;
    --font-size-xs: 12px;
    --line-height: 1.6;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;

    /* Border radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px var(--glow-primary);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s ease;
}

/* === Reset & Base === */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: var(--font-size-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height);
    color: var(--text-primary);
    background: var(--bg-primary);
    min-height: 100vh;
}

/* === Typography === */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
}

h1 {
    font-size: var(--font-size-xxl);
}

h2 {
    font-size: var(--font-size-xl);
}

h3 {
    font-size: var(--font-size-lg);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

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

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

/* === App Container === */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* === Animated Background === */
.app-bg {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.app-bg::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background:
        radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(16, 185, 129, 0.05) 0%, transparent 40%);
    animation: bgPulse 20s ease-in-out infinite;
}

@keyframes bgPulse {

    0%,
    100% {
        transform: translate(0, 0) scale(1);
        opacity: 1;
    }

    50% {
        transform: translate(-2%, 2%) scale(1.05);
        opacity: 0.8;
    }
}

/* === Navbar === */
.navbar {
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-brand {
    font-size: var(--font-size-lg);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-nav {
    display: flex;
    gap: var(--spacing-md);
    list-style: none;
}

.navbar-nav a {
    color: var(--text-muted);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.navbar-nav a:hover,
.navbar-nav a.active {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.navbar-user {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-name {
    font-weight: 500;
    color: var(--text-secondary);
}

/* === Main Content === */
.main-content {
    flex: 1;
    padding: var(--spacing-xl);
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
    position: relative;
    z-index: 1;
}

/* === Cards === */
.card {
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: all var(--transition-normal);
}

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

.card-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.2);
}

.card-header h2,
.card-header h3 {
    margin: 0;
    color: var(--text-primary);
}

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

.card-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.2);
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-base);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    line-height: 1.5;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.5s ease;
}

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

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

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
    color: white;
}

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

.btn-secondary:hover:not(:disabled) {
    background: rgba(148, 163, 184, 0.2);
    border-color: var(--primary-light);
}

.btn-success {
    background: var(--gradient-success);
    color: white;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-success:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

.btn-danger {
    background: var(--gradient-danger);
    color: white;
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
}

.btn-danger:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(239, 68, 68, 0.4);
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
}

.btn-block {
    width: 100%;
}

/* === Forms === */
.form-group {
    margin-bottom: var(--spacing-lg);
}

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

.form-control {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
    font-family: inherit;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: rgba(15, 23, 42, 0.6);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

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

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--glow-primary);
}

.form-control:hover:not(:focus) {
    border-color: rgba(148, 163, 184, 0.4);
}

.form-control:disabled {
    background: var(--bg-tertiary);
    cursor: not-allowed;
    opacity: 0.6;
}

textarea.form-control {
    min-height: 120px;
    resize: vertical;
}

select.form-control {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%2394a3b8' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    padding-right: 2.5rem;
}

.form-text {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
}

.form-error {
    color: var(--danger);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
}

/* === Alerts === */
.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
    border: 1px solid;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.alert-success {
    background: var(--success-light);
    color: #34d399;
    border-color: rgba(16, 185, 129, 0.3);
}

.alert-error {
    background: var(--danger-light);
    color: #f87171;
    border-color: rgba(239, 68, 68, 0.3);
}

.alert-warning {
    background: var(--warning-light);
    color: #fbbf24;
    border-color: rgba(245, 158, 11, 0.3);
}

.alert-info {
    background: var(--info-light);
    color: #60a5fa;
    border-color: rgba(59, 130, 246, 0.3);
}

/* === Badges === */
.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-xs);
    font-weight: 600;
    border-radius: 50px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.badge-primary {
    background: rgba(99, 102, 241, 0.2);
    color: var(--primary-light);
    border: 1px solid rgba(99, 102, 241, 0.3);
}

.badge-success {
    background: var(--success-light);
    color: #34d399;
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-danger {
    background: var(--danger-light);
    color: #f87171;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.badge-warning {
    background: var(--warning-light);
    color: #fbbf24;
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-secondary {
    background: rgba(148, 163, 184, 0.15);
    color: var(--text-muted);
    border: 1px solid var(--border-color);
}

/* === Tables === */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-md);
}

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

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

.table th {
    font-weight: 600;
    background: rgba(0, 0, 0, 0.3);
    color: var(--text-muted);
    font-size: var(--font-size-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.table tbody tr {
    transition: background var(--transition-fast);
}

.table tbody tr:hover {
    background: rgba(99, 102, 241, 0.05);
}

/* === Grid === */
.grid {
    display: grid;
    gap: var(--spacing-lg);
}

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

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

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

@media (max-width: 768px) {

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

/* === Login Page === */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

.login-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
}

.login-bg::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background:
        radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(16, 185, 129, 0.08) 0%, transparent 40%);
    animation: bgPulse 15s ease-in-out infinite;
}

.login-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.5;
    animation: orbFloat 20s ease-in-out infinite;
}

.login-orb-1 {
    width: 400px;
    height: 400px;
    background: var(--primary);
    top: -100px;
    right: -100px;
}

.login-orb-2 {
    width: 300px;
    height: 300px;
    background: var(--accent);
    bottom: -50px;
    left: -50px;
    animation-delay: -10s;
}

@keyframes orbFloat {

    0%,
    100% {
        transform: translate(0, 0);
    }

    25% {
        transform: translate(20px, -20px);
    }

    50% {
        transform: translate(-15px, 15px);
    }

    75% {
        transform: translate(15px, 20px);
    }
}

.login-card {
    width: 100%;
    max-width: 440px;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    position: relative;
    z-index: 1;
    box-shadow: var(--shadow-lg);
    animation: cardSlideUp 0.6s ease-out;
}

@keyframes cardSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

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

.login-header {
    text-align: center;
    padding: var(--spacing-xl);
    background: var(--gradient-primary);
    position: relative;
}

.login-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.login-icon {
    width: 72px;
    height: 72px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-lg);
    font-size: 2.5rem;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
}

.login-header h1 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
    color: white;
    position: relative;
}

.login-header p {
    color: rgba(255, 255, 255, 0.85);
    margin: 0;
    position: relative;
}

.login-body {
    padding: var(--spacing-xl);
}

.login-footer {
    padding: var(--spacing-lg) var(--spacing-xl);
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.login-footer a {
    color: var(--primary-light);
}

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

/* === Stats Cards === */
.stat-card {
    text-align: center;
    padding: var(--spacing-xl);
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
    border-color: var(--primary-light);
}

.stat-icon {
    width: 56px;
    height: 56px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
    font-size: 1.5rem;
}

.stat-value {
    font-size: var(--font-size-xxl);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

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

.empty-state svg {
    width: 64px;
    height: 64px;
    margin-bottom: var(--spacing-lg);
    opacity: 0.5;
}

/* === Utilities === */
.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-primary {
    color: var(--primary-light);
}

.mt-sm {
    margin-top: var(--spacing-sm);
}

.mt-md {
    margin-top: var(--spacing-md);
}

.mt-lg {
    margin-top: var(--spacing-lg);
}

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

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

.mb-lg {
    margin-bottom: var(--spacing-lg);
}

.d-flex {
    display: flex;
}

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

.align-center {
    align-items: center;
}

.gap-sm {
    gap: var(--spacing-sm);
}

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

.gap-lg {
    gap: var(--spacing-lg);
}

.hidden {
    display: none !important;
}

/* === Responsive === */
@media (max-width: 768px) {
    :root {
        --font-size-base: 15px;
        --spacing-lg: 20px;
        --spacing-xl: 24px;
    }

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

    .main-content {
        padding: var(--spacing-md);
    }

    .login-card {
        margin: var(--spacing-md);
    }
}

/* === Print === */
@media print {

    .navbar,
    .btn,
    .no-print {
        display: none !important;
    }

    body {
        background: white;
        color: black;
    }

    .card {
        box-shadow: none;
        border: 1px solid #ddd;
        background: white;
    }
}