/* Modern CSS Reset */
*, *::before, *::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: #1a1a2e;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* CSS Variables */
:root {
    --primary: #667eea;
    --primary-dark: #5a67d8;
    --secondary: #764ba2;
    --accent: #f093fb;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --dark: #1a1a2e;
    --light: #f8fafc;
    --gray: #64748b;
    --gray-light: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Glass Effect Cards */
.glass {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    outline: none;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary:hover {
    background: #d1d5db;
}

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

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

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

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

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

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

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

.btn-lg {
    padding: 16px 32px;
    font-size: 17px;
}

.btn-block {
    width: 100%;
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--dark);
    font-size: 14px;
}

.form-control {
    width: 100%;
    padding: 14px 16px;
    font-size: 15px;
    border: 2px solid var(--gray-light);
    border-radius: var(--radius);
    transition: var(--transition);
    outline: none;
    background: white;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.15);
}

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

select.form-control {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 20px;
    padding-right: 44px;
}

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

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--gray-light);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, rgba(118, 75, 162, 0.05) 100%);
}

.card-body {
    padding: 24px;
}

.card-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--gray-light);
    background: var(--light);
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

.navbar-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-brand {
    font-size: 24px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: 8px;
    list-style: none;
}

.nav-link {
    padding: 10px 16px;
    color: var(--gray);
    text-decoration: none;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
    color: var(--primary);
    background: rgba(102, 126, 234, 0.1);
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 16px;
    background: var(--light);
    border-radius: 50px;
}

.nav-user-avatar {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
    font-size: 14px;
}

/* Auth Pages */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.auth-card {
    width: 100%;
    max-width: 440px;
    padding: 48px;
}

.auth-header {
    text-align: center;
    margin-bottom: 40px;
}

.auth-logo {
    font-size: 48px;
    margin-bottom: 16px;
}

.auth-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 8px;
}

.auth-subtitle {
    color: var(--gray);
    font-size: 15px;
}

.auth-footer {
    text-align: center;
    margin-top: 24px;
    color: var(--gray);
}

.auth-footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

.auth-footer a:hover {
    text-decoration: underline;
}

/* Dashboard */
.dashboard {
    padding: 32px 0;
}

.dashboard-header {
    margin-bottom: 32px;
}

.dashboard-title {
    font-size: 32px;
    font-weight: 700;
    color: white;
    margin-bottom: 8px;
}

.dashboard-subtitle {
    color: rgba(255, 255, 255, 0.8);
    font-size: 16px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.stat-card {
    padding: 24px;
}

.stat-card-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin-bottom: 16px;
}

.stat-card-icon.primary {
    background: rgba(102, 126, 234, 0.1);
    color: var(--primary);
}

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

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

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

.stat-card-value {
    font-size: 36px;
    font-weight: 700;
    color: var(--dark);
    line-height: 1;
    margin-bottom: 4px;
}

.stat-card-label {
    color: var(--gray);
    font-size: 14px;
}

/* Tests Grid */
.tests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.test-card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.test-card:hover {
    transform: translateY(-4px);
}

.test-card-header {
    padding: 24px;
    border-bottom: 1px solid var(--gray-light);
}

.test-card-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 8px;
}

.test-card-desc {
    color: var(--gray);
    font-size: 14px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.test-card-body {
    padding: 24px;
}

.test-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.test-meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--gray);
}

.test-meta-item i {
    color: var(--primary);
}

.test-card-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--gray-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Taking Test */
.test-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 32px 20px;
}

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

.test-timer {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    border-radius: 50px;
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
}

.test-timer.warning {
    animation: pulse 1s infinite;
}

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

.test-progress {
    margin-bottom: 24px;
}

.progress-bar-container {
    background: var(--gray-light);
    border-radius: 50px;
    height: 8px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: 50px;
    transition: width 0.3s ease;
}

.progress-text {
    text-align: center;
    margin-top: 8px;
    font-size: 14px;
    color: var(--gray);
}

.question-card {
    margin-bottom: 24px;
}

.question-number {
    display: inline-block;
    padding: 6px 14px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 16px;
}

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

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

.option-item {
    position: relative;
}

.option-input {
    position: absolute;
    opacity: 0;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 18px 20px;
    background: var(--light);
    border: 2px solid var(--gray-light);
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
}

.option-label:hover {
    border-color: var(--primary);
    background: rgba(102, 126, 234, 0.05);
}

.option-input:checked + .option-label {
    border-color: var(--primary);
    background: rgba(102, 126, 234, 0.1);
}

.option-marker {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: white;
    border: 2px solid var(--gray-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--gray);
    transition: var(--transition);
    flex-shrink: 0;
}

.option-input:checked + .option-label .option-marker {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.option-text {
    font-size: 15px;
    color: var(--dark);
}

.test-navigation {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    margin-top: 32px;
}

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

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

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

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

.result-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
}

.result-title.passed {
    color: var(--success);
}

.result-title.failed {
    color: var(--danger);
}

.result-score {
    font-size: 72px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin: 24px 0;
}

.result-details {
    display: flex;
    justify-content: center;
    gap: 48px;
    margin-top: 32px;
    padding-top: 32px;
    border-top: 1px solid var(--gray-light);
}

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

.result-detail-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--dark);
}

.result-detail-label {
    font-size: 14px;
    color: var(--gray);
}

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

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

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

.table th {
    font-weight: 600;
    color: var(--dark);
    background: var(--light);
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.table tr:hover td {
    background: rgba(102, 126, 234, 0.02);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 12px;
    font-size: 12px;
    font-weight: 600;
    border-radius: 50px;
}

.badge-primary {
    background: rgba(102, 126, 234, 0.1);
    color: var(--primary);
}

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

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

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

.badge-gray {
    background: rgba(100, 116, 139, 0.1);
    color: var(--gray);
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

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

.modal {
    background: white;
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    transform: translateY(20px);
    transition: var(--transition);
}

.modal-overlay.active .modal {
    transform: translateY(0);
}

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

.modal-title {
    font-size: 20px;
    font-weight: 700;
}

.modal-close {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--light);
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--gray);
    transition: var(--transition);
}

.modal-close:hover {
    background: var(--gray-light);
    color: var(--dark);
}

.modal-body {
    padding: 24px;
}

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

/* Alerts */
.alert {
    padding: 16px 20px;
    border-radius: var(--radius);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

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

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

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

/* Loading */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 48px;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--gray-light);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Utilities */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.text-gray {
    color: var(--gray);
}

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

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

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

.font-bold {
    font-weight: 700;
}

.mb-0 {
    margin-bottom: 0;
}

.mb-1 {
    margin-bottom: 8px;
}

.mb-2 {
    margin-bottom: 16px;
}

.mb-3 {
    margin-bottom: 24px;
}

.mb-4 {
    margin-bottom: 32px;
}

.mt-2 {
    margin-top: 16px;
}

.mt-3 {
    margin-top: 24px;
}

.mt-4 {
    margin-top: 32px;
}

.d-flex {
    display: flex;
}

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

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

.gap-2 {
    gap: 16px;
}

.hidden {
    display: none;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar-nav {
        display: none;
    }

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

    .tests-grid {
        grid-template-columns: 1fr;
    }

    .auth-card {
        padding: 32px 24px;
    }

    .result-details {
        flex-direction: column;
        gap: 24px;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .test-navigation {
        flex-direction: column;
    }

    .test-navigation .btn {
        width: 100%;
    }
}