:root {
    --color-primary: #4f46e5;
    --color-secondary: #1e1b4b;
    --color-accent: #facc15;
    --color-text: #1f2937;
    --color-muted: #6b7280;
    --color-background: #f9fafb;
    --radius-large: 24px;
    --radius-medium: 16px;
    --radius-small: 8px;
    --shadow-soft: 0 20px 40px rgba(79, 70, 229, 0.1);
    --font-display: 'Poppins', 'Segoe UI', sans-serif;
    --font-body: 'Inter', 'Roboto', sans-serif;
}

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

body {
    font-family: var(--font-body);
    background: linear-gradient(180deg, #eef2ff 0%, #ffffff 45%, var(--color-background) 100%);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.container {
    width: min(1080px, 90vw);
    margin: 0 auto;
}

.site-header {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(16px);
    position: sticky;
    top: 0;
    z-index: 50;
    border-bottom: 1px solid rgba(79, 70, 229, 0.1);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 0;
}

.brand {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.4rem;
    color: var(--color-primary);
}

.menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 1px solid rgba(79, 70, 229, 0.2);
    border-radius: var(--radius-small);
    background: #fff;
    cursor: pointer;
    transition: background 0.2s ease, border-color 0.2s ease;
}

.menu-toggle:hover {
    background: rgba(79, 70, 229, 0.08);
    border-color: rgba(79, 70, 229, 0.4);
}

.menu-toggle__bar {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-secondary);
    border-radius: 999px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.menu-toggle__bar + .menu-toggle__bar {
    margin-top: 5px;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    font-weight: 500;
    color: var(--color-muted);
}

.nav-links a:hover {
    color: var(--color-primary);
}

.menu-toggle.is-active .menu-toggle__bar:nth-child(2) {
    transform: translateY(7px) rotate(45deg);
}

.menu-toggle.is-active .menu-toggle__bar:nth-child(3) {
    opacity: 0;
}

.menu-toggle.is-active .menu-toggle__bar:nth-child(4) {
    transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 768px) {
    .site-header .container {
        flex-wrap: wrap;
        gap: 1rem;
    }

    .menu-toggle {
        display: inline-flex;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        width: 100%;
        padding-top: 1rem;
        gap: 1rem;
        border-top: 1px solid rgba(79, 70, 229, 0.12);
        color: var(--color-secondary);
    }

    .nav-links a {
        padding: 0.25rem 0;
    }

    .nav-links.is-open {
        display: flex;
    }
}

.hero {
    padding: 6rem 0 4rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    align-items: center;
    gap: 3rem;
}

.hero-copy h1 {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: clamp(2.8rem, 4vw + 1rem, 4rem);
    line-height: 1.1;
    color: var(--color-secondary);
    margin-bottom: 1.5rem;
}

.hero-copy p {
    font-size: 1.1rem;
    color: var(--color-muted);
    margin-bottom: 2rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    padding: 0.95rem 1.8rem;
    border-radius: var(--radius-large);
    border: none;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary {
    background: var(--color-primary);
    color: #fff;
    box-shadow: var(--shadow-soft);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 24px 48px rgba(79, 70, 229, 0.25);
}

.btn-secondary {
    background: rgba(79, 70, 229, 0.08);
    color: var(--color-primary);
}

.highlight-card {
    background: #fff;
    border-radius: var(--radius-large);
    box-shadow: var(--shadow-soft);
    padding: 2.5rem;
    display: grid;
    gap: 1.5rem;
    border: 1px solid rgba(79, 70, 229, 0.1);
}

.metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1.5rem;
}

.metric {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.metric span:first-child {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
}

.metric span:last-child {
    color: var(--color-muted);
    font-weight: 500;
}

.section {
    padding: 5rem 0;
}

.section-heading {
    text-align: center;
    margin-bottom: 3rem;
}

.section-heading h2 {
    font-family: var(--font-display);
    font-size: clamp(2rem, 3vw + 1rem, 3rem);
    color: var(--color-secondary);
    margin-bottom: 1rem;
}

.section-heading p {
    color: var(--color-muted);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 2rem;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(79, 70, 229, 0.08);
    display: grid;
    gap: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    color: var(--color-secondary);
}

.feature-card p {
    color: var(--color-muted);
}

.chatgpt-card {
    background: #fff;
    border-radius: var(--radius-large);
    padding: 2.5rem;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(79, 70, 229, 0.08);
    display: grid;
    gap: 2rem;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    align-items: start;
}

.chatgpt-card-body {
    display: grid;
    gap: 1rem;
}

.chatgpt-card-body h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-secondary);
}

.chatgpt-card-body p {
    color: var(--color-muted);
}

.chatgpt-card-status {
    background: rgba(79, 70, 229, 0.05);
    border-radius: var(--radius-medium);
    padding: 1.75rem;
    display: grid;
    gap: 0.75rem;
}

.chatgpt-status-label {
    font-weight: 600;
    color: var(--color-secondary);
}

.chatgpt-status-value {
    font-family: 'Courier New', 'SFMono-Regular', ui-monospace, monospace;
    font-size: 1rem;
    padding: 0.75rem 1rem;
    background: #fff;
    border: 1px dashed rgba(79, 70, 229, 0.4);
    border-radius: var(--radius-small);
    word-break: break-all;
}

.chatgpt-invitation-input {
    padding: 0.75rem 1rem;
    border: 1px solid rgba(79, 70, 229, 0.4);
    border-radius: var(--radius-small);
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    width: 100%;
}

.chatgpt-invitation-input:focus {
    outline: 2px solid rgba(79, 70, 229, 0.4);
    outline-offset: 2px;
}

.chatgpt-invitation-input[aria-invalid="true"] {
    border-color: #b91c1c;
}

.chatgpt-status-helper {
    font-size: 0.9rem;
    color: var(--color-muted);
}

.chatgpt-feedback {
    margin-top: 1.5rem;
    font-size: 0.95rem;
    font-weight: 500;
    min-height: 1.5rem;
}

.chatgpt-feedback.is-success {
    color: #15803d;
}

.chatgpt-feedback.is-error {
    color: #b91c1c;
}

.testimonials {
    display: grid;
    gap: 1.5rem;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.testimonial-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 2rem;
    border: 1px solid rgba(79, 70, 229, 0.1);
    box-shadow: var(--shadow-soft);
    display: grid;
    gap: 1.25rem;
}

.testimonial-card .quote {
    font-style: italic;
    color: var(--color-secondary);
}

.testimonial-card .author {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.testimonial-card .author span:first-child {
    font-weight: 600;
    color: var(--color-primary);
}

.cta {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.92), rgba(30, 27, 75, 0.95));
    border-radius: var(--radius-large);
    padding: 3rem;
    color: #fff;
    text-align: center;
    box-shadow: var(--shadow-soft);
}

.cta h2 {
    font-family: var(--font-display);
    font-size: clamp(2rem, 3vw + 1rem, 3rem);
    margin-bottom: 1rem;
}

.cta p {
    margin-bottom: 2rem;
    color: rgba(255, 255, 255, 0.85);
}

.contact-form {
    display: grid;
    gap: 1.5rem;
    max-width: 520px;
    margin: 0 auto;
    text-align: left;
}

.contact-form .form-group label {
    color: rgba(255, 255, 255, 0.9);
}

.contact-field {
    width: 100%;
    padding: 0.85rem 1.1rem;
    border-radius: var(--radius-medium);
    border: 1px solid rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    font: inherit;
    transition: border 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.contact-field::placeholder {
    color: rgba(255, 255, 255, 0.65);
}

.contact-field:focus {
    outline: none;
    border-color: rgba(250, 204, 21, 0.65);
    background: rgba(255, 255, 255, 0.16);
    box-shadow: 0 0 0 3px rgba(250, 204, 21, 0.22);
}

.contact-form textarea.contact-field {
    min-height: 160px;
    resize: vertical;
}

.contact-alert {
    border-radius: var(--radius-medium);
    padding: 1rem 1.25rem;
    margin-bottom: 1.75rem;
    font-weight: 500;
    border: 1px solid transparent;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.contact-alert--success {
    background: rgba(22, 163, 74, 0.18);
    border-color: rgba(134, 239, 172, 0.4);
    color: #dcfce7;
}

.contact-alert--error {
    background: rgba(220, 38, 38, 0.22);
    border-color: rgba(248, 113, 113, 0.4);
    color: #fee2e2;
}

.contact-alert--invalid {
    background: rgba(234, 179, 8, 0.2);
    border-color: rgba(253, 224, 71, 0.45);
    color: #fef3c7;
}

.site-footer {
    padding: 2rem 0;
    text-align: center;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.site-footer span {
    color: var(--color-primary);
    font-weight: 600;
}

.container-narrow {
    width: min(680px, 90vw);
    margin: 0 auto;
}

.page-hero {
    padding: 6rem 0 2rem;
}

.page-hero h1 {
    font-family: var(--font-display);
    font-size: clamp(2.4rem, 3vw + 1rem, 3.4rem);
    color: var(--color-secondary);
    margin-bottom: 1rem;
}

.page-lead {
    font-size: 1.1rem;
    color: var(--color-muted);
    margin-bottom: 2rem;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.85rem;
    margin-bottom: 1rem;
}

.page-subtitle {
    font-weight: 600;
    color: var(--color-secondary);
    margin-bottom: 1.25rem;
}

.form-card {
    background: #fff;
    border-radius: var(--radius-large);
    padding: 2.5rem;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(79, 70, 229, 0.08);
    display: grid;
    gap: 1.5rem;
}

.form-card form {
    display: grid;
    gap: 1.5rem;
}

.form-group {
    display: grid;
    gap: 0.6rem;
}

.form-group label {
    font-weight: 600;
    color: var(--color-secondary);
}

.input-field,
.select-field,
.feedback-area textarea,
.score-input input {
    width: 100%;
    padding: 0.85rem 1rem;
    border-radius: var(--radius-medium);
    border: 1px solid rgba(31, 41, 55, 0.15);
    background: #f9f9ff;
    font: inherit;
    transition: border 0.2s ease, box-shadow 0.2s ease;
}

.input-field:focus,
.select-field:focus,
.feedback-area textarea:focus,
.score-input input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
    background: #fff;
}

.form-inline {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.95rem;
}

.form-inline label {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.form-inline input[type="checkbox"] {
    width: 1rem;
    height: 1rem;
}

.form-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.link-muted {
    color: var(--color-muted);
    font-weight: 500;
}

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

.info-list {
    display: grid;
    gap: 1rem;
}

.info-item {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.info-item strong {
    color: var(--color-secondary);
}

.section-intro {
    display: grid;
    gap: 1rem;
    margin-bottom: 3rem;
    text-align: center;
}

.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
}

.filter-bar .select-field {
    width: auto;
    min-width: 220px;
}

.exam-grid {
    display: grid;
    gap: 2rem;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.exam-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 2rem;
    border: 1px solid rgba(79, 70, 229, 0.08);
    box-shadow: var(--shadow-soft);
    display: grid;
    gap: 1.25rem;
}

.exam-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
}

.exam-card-header h3 {
    color: var(--color-secondary);
    font-size: 1.25rem;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-weight: 600;
    font-size: 0.85rem;
    padding: 0.45rem 0.75rem;
    border-radius: 999px;
}

.status-open {
    background: rgba(22, 163, 74, 0.12);
    color: #15803d;
}

.status-scheduled {
    background: rgba(234, 179, 8, 0.12);
    color: #b45309;
}

.status-closed {
    background: rgba(99, 102, 241, 0.12);
    color: #4338ca;
}

.exam-meta {
    display: grid;
    gap: 1rem;
}

.meta-item {
    display: flex;
    justify-content: space-between;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.meta-item span:first-child {
    font-weight: 600;
    color: var(--color-secondary);
}

.evaluation-grid {
    display: grid;
    gap: 2rem;
    grid-template-columns: minmax(0, 320px) minmax(0, 1fr);
    align-items: start;
}

.profile-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 2rem;
    border: 1px solid rgba(79, 70, 229, 0.08);
    box-shadow: var(--shadow-soft);
    display: grid;
    gap: 1rem;
}

.detail-row {
    display: flex;
    justify-content: space-between;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.detail-label {
    font-weight: 600;
    color: var(--color-secondary);
}

.progress-summary {
    display: grid;
    gap: 1rem;
    background: rgba(79, 70, 229, 0.08);
    padding: 1.5rem;
    border-radius: var(--radius-medium);
}

.progress-bar {
    background: rgba(79, 70, 229, 0.15);
    border-radius: 999px;
    height: 10px;
    overflow: hidden;
}

.progress-bar-fill {
    display: block;
    height: 100%;
    width: 0;
    background: var(--color-primary);
    transition: width 0.3s ease;
}

.question-list {
    display: grid;
    gap: 1.5rem;
}

.question-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 1.75rem;
    border: 1px solid rgba(79, 70, 229, 0.08);
    box-shadow: var(--shadow-soft);
    display: grid;
    gap: 1.25rem;
}

.exam-layout {
    background: rgba(255, 255, 255, 0.85);
    border-radius: var(--radius-large);
    padding: 2.5rem;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(79, 70, 229, 0.12);
    display: grid;
    gap: 2rem;
}

.exam-header {
    display: grid;
    gap: 0.75rem;
}

.exam-title {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 1.2vw + 1.5rem, 2.4rem);
    color: var(--color-secondary);
}

.exam-lead {
    color: var(--color-muted);
    max-width: 48ch;
}

.exam-form {
    display: grid;
    gap: 2rem;
}

.question-stack {
    display: grid;
    gap: 1.5rem;
}

.exam-question {
    box-shadow: none;
    border-radius: var(--radius-medium);
    border: 1px solid rgba(79, 70, 229, 0.08);
    background: #fff;
}

.question-text {
    font-size: 1.05rem;
    color: var(--color-secondary);
}

.option-list {
    display: grid;
    gap: 0.75rem;
}

.option-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    border: 1px solid rgba(79, 70, 229, 0.15);
    border-radius: var(--radius-medium);
    padding: 0.9rem 1rem;
    background: rgba(79, 70, 229, 0.04);
    transition: border-color 0.2s ease, background 0.2s ease;
}

.option-item input[type="radio"] {
    margin-top: 0.3rem;
}

.option-item span {
    color: var(--color-secondary);
    line-height: 1.5;
}

.option-item:hover {
    border-color: var(--color-primary);
    background: rgba(79, 70, 229, 0.08);
}

.exam-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.results-layout {
    background: rgba(255, 255, 255, 0.92);
}

.exam-results-summary {
    display: grid;
    gap: 1.25rem;
    padding: 1.75rem;
    border-radius: var(--radius-medium);
    background: rgba(79, 70, 229, 0.06);
    border: 1px solid rgba(79, 70, 229, 0.12);
}

.exam-results-summary strong {
    display: block;
    color: var(--color-secondary);
    margin-bottom: 0.35rem;
}

.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.35rem 0.85rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
}

.badge-success {
    background: rgba(34, 197, 94, 0.15);
    color: #15803d;
}

.badge-error {
    background: rgba(168, 85, 247, 0.15);
    color: #6b21a8;
}

.result-card {
    box-shadow: none;
    border-radius: var(--radius-medium);
    border: 1px solid rgba(79, 70, 229, 0.08);
    background: rgba(255, 255, 255, 0.95);
}

.result-card-success {
    border-color: rgba(34, 197, 94, 0.25);
}

.result-card-error {
    border-color: rgba(168, 85, 247, 0.25);
}

.question-header {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: space-between;
    align-items: center;
}

.question-title {
    font-weight: 600;
    color: var(--color-secondary);
}

.question-body {
    color: var(--color-muted);
    display: grid;
    gap: 0.75rem;
}

.question-actions {
    display: grid;
    gap: 1rem;
}

.score-input {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.score-input label {
    font-weight: 600;
    color: var(--color-secondary);
}

.score-input input {
    max-width: 120px;
}

.feedback-area {
    display: grid;
    gap: 0.5rem;
}

.feedback-area label {
    font-weight: 600;
    color: var(--color-secondary);
}

.feedback-area textarea {
    min-height: 120px;
    resize: vertical;
}

.results-summary {
    display: grid;
    gap: 2rem;
}

.results-metrics {
    display: grid;
    gap: 1.5rem;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.metric-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 1.75rem;
    border: 1px solid rgba(79, 70, 229, 0.08);
    box-shadow: var(--shadow-soft);
    display: grid;
    gap: 0.65rem;
}

.metric-card h3 {
    font-size: 1rem;
    color: var(--color-secondary);
}

.metric-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
}

.results-table-wrapper {
    overflow-x: auto;
}

.results-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 640px;
}

.results-table th,
.results-table td {
    padding: 0.9rem 1rem;
    text-align: left;
}

.results-table thead {
    background: rgba(79, 70, 229, 0.08);
}

.results-table tbody tr:nth-child(odd) {
    background: rgba(79, 70, 229, 0.03);
}

.tag {
    display: inline-flex;
    align-items: center;
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
}

.tag-success {
    background: rgba(22, 163, 74, 0.15);
    color: #15803d;
}

.tag-warning {
    background: rgba(234, 179, 8, 0.18);
    color: #b45309;
}

.tag-info {
    background: rgba(59, 130, 246, 0.15);
    color: #1d4ed8;
}

.support-card {
    background: #fff;
    border-radius: var(--radius-medium);
    padding: 2rem;
    border: 1px solid rgba(79, 70, 229, 0.08);
    box-shadow: var(--shadow-soft);
    display: grid;
    gap: 1rem;
}

@media (max-width: 640px) {
    .site-header .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero {
        padding-top: 4rem;
    }

    .hero-actions {
        width: 100%;
    }

    .btn {
        flex: 1;
    }

    .form-card,
    .profile-card,
    .exam-card,
    .metric-card,
    .question-card {
        padding: 1.75rem;
    }

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

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