/* --- Base Semantic Tokens (WCAG AAA compliant) --- */
:root {
  --font-serif: "Newsreader", "Iowan Old Style", "Apple Garamond", Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", Menlo, monospace;

  /* Light theme (default) */
  --bg-canvas: #f8f9fa;
  --bg-surface: #ffffff;
  --bg-surface-raised: #f1f3f5;
  --bg-subtle: #e9ecef;
  --text-primary: #111317;
  --text-secondary: #383d47;
  --text-muted: #575e6d;
  --border-subtle: #dee2e6;
  --border-prominent: #adb5bd;
  --accent-primary: #1558b0;
  --accent-hover: #0d428a;
  --accent-subtle: #e8f0fe;
  --color-success: #1b6d32;
  --color-success-bg: #e6f4ea;
  --color-danger: #a51d24;
  --color-danger-bg: #fce8e6;
  --color-warning: #855302;
  --color-warning-bg: #fef7e0;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
}

[data-theme="dark"] {
  --bg-canvas: #0b0d11;
  --bg-surface: #131720;
  --bg-surface-raised: #1c2230;
  --bg-subtle: #242c3d;
  --text-primary: #f6f7f9;
  --text-secondary: #d0d5df;
  --text-muted: #9aa2b1;
  --border-subtle: #283144;
  --border-prominent: #43506d;
  --accent-primary: #38bdf8;
  --accent-hover: #7dd3fc;
  --accent-subtle: #082f49;
  --color-success: #34d399;
  --color-success-bg: #064e3b;
  --color-danger: #f87171;
  --color-danger-bg: #450a0a;
  --color-warning: #fbbf24;
  --color-warning-bg: #451a03;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 16px rgba(0, 0, 0, 0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-canvas: #0b0d11;
    --bg-surface: #131720;
    --bg-surface-raised: #1c2230;
    --bg-subtle: #242c3d;
    --text-primary: #f6f7f9;
    --text-secondary: #d0d5df;
    --text-muted: #9aa2b1;
    --border-subtle: #283144;
    --border-prominent: #43506d;
    --accent-primary: #38bdf8;
    --accent-hover: #7dd3fc;
    --accent-subtle: #082f49;
    --color-success: #34d399;
    --color-success-bg: #064e3b;
    --color-danger: #f87171;
    --color-danger-bg: #450a0a;
    --color-warning: #fbbf24;
    --color-warning-bg: #451a03;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 6px 16px rgba(0, 0, 0, 0.5);
  }
}

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

html {
  font-size: 17px;
  line-height: 1.65;
  color: var(--text-primary);
  background-color: var(--bg-canvas);
  -webkit-text-size-adjust: 100%;
  font-feature-settings: "kern", "liga", "clig", "calt";
  font-family: var(--font-sans);
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--accent-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.15s ease;
}

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

:focus-visible {
  outline: 3px solid var(--accent-primary);
  outline-offset: 2px;
}

/* --- Sticky Topbar (House Pattern) --- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background-color: rgba(248, 249, 250, 0.88);
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

[data-theme="dark"] .topbar {
  background-color: rgba(11, 13, 17, 0.88);
}

.topbar-inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 0.6rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.85rem;
  font-weight: 500;
}

.topbar-left, .topbar-right {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.topbar-brand {
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.topbar-links {
  display: flex;
  gap: 0.75rem;
}

.topbar-link {
  color: var(--text-muted);
  text-decoration: none;
}

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

.icon-btn {
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.35rem 0.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  transition: all 0.15s ease;
}

.icon-btn:hover {
  background-color: var(--bg-surface-raised);
  color: var(--text-primary);
  border-color: var(--border-prominent);
}

.icon-btn svg[hidden] {
  display: none;
}

.lang-switch {
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.25rem 0.45rem;
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
}

.lang-switch:hover {
  background-color: var(--bg-surface-raised);
  color: var(--text-primary);
}

/* --- Main Layout --- */
.container {
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
  flex: 1;
}

/* --- Hero & Intro --- */
.hero {
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 2rem;
}

.kicker {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-primary);
  margin-bottom: 0.75rem;
}

.page-title {
  font-family: var(--font-serif);
  font-size: clamp(1.9rem, 4.5vw, 2.7rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 1.2rem;
}

.lead-p {
  font-size: 1.12rem;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

/* --- Live Comparison Banner --- */
.benchmark-banner {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.75rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 1rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
}

.benchmark-card {
  text-align: center;
  padding: 0.5rem;
}

.benchmark-card-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.benchmark-card-value {
  font-family: var(--font-serif);
  font-size: 1.65rem;
  font-weight: 700;
  line-height: 1.1;
}

.benchmark-card-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.val-human { color: var(--color-success); }
.val-gemini { color: var(--accent-primary); }
.val-gpt { color: #f97316; }
.val-user { color: var(--text-primary); }

/* --- Interactive Quiz Container --- */
.quiz-section {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  overflow: hidden;
  margin-bottom: 3.5rem;
}

.quiz-header {
  padding: 1rem 1.25rem;
  background-color: var(--bg-surface-raised);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.quiz-progress-text {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

.quiz-category-tag {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.25rem 0.55rem;
  border-radius: 4px;
  background-color: var(--accent-subtle);
  color: var(--accent-primary);
}

.progress-bar-wrap {
  width: 100%;
  height: 4px;
  background-color: var(--border-subtle);
}

.progress-bar-fill {
  height: 100%;
  background-color: var(--accent-primary);
  width: 10%;
  transition: width 0.3s ease;
}

/* --- Video Container --- */
.quiz-body {
  padding: 1.25rem;
}

.video-container {
  position: relative;
  width: 100%;
  background-color: #000000;
  border-radius: 8px;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border-subtle);
}

.quiz-video {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.video-controls-overlay {
  position: absolute;
  bottom: 0.5rem;
  right: 0.5rem;
  display: flex;
  gap: 0.4rem;
  z-index: 10;
}

.video-btn {
  background: rgba(19, 23, 32, 0.75);
  backdrop-filter: blur(4px);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  padding: 0.35rem 0.6rem;
  font-size: 0.75rem;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: background-color 0.15s;
}

.video-btn:hover {
  background: rgba(19, 23, 32, 0.95);
}

/* --- Question & Options --- */
.question-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.35;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.options-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.6rem;
  margin-bottom: 1.25rem;
}

@media (min-width: 540px) {
  .options-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.option-btn {
  background-color: var(--bg-surface-raised);
  border: 1.5px solid var(--border-subtle);
  border-radius: 8px;
  padding: 0.8rem 1rem;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-primary);
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  transition: all 0.15s ease;
  min-height: 52px;
}

.option-btn:hover:not(:disabled) {
  background-color: var(--bg-subtle);
  border-color: var(--accent-primary);
}

.option-btn:disabled {
  cursor: default;
}

.option-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 4px;
  background-color: var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 700;
  flex-shrink: 0;
}

/* Option feedback states */
.option-btn.state-correct {
  background-color: var(--color-success-bg);
  border-color: var(--color-success);
  color: var(--color-success);
}
.option-btn.state-correct .option-letter {
  background-color: var(--color-success);
  color: #ffffff;
}

.option-btn.state-wrong {
  background-color: var(--color-danger-bg);
  border-color: var(--color-danger);
  color: var(--color-danger);
  opacity: 0.85;
}
.option-btn.state-wrong .option-letter {
  background-color: var(--color-danger);
  color: #ffffff;
}

.option-btn.state-faded {
  opacity: 0.45;
}

/* --- Feedback Card --- */
.feedback-box {
  border-radius: 8px;
  padding: 1.1rem;
  margin-top: 1rem;
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-surface-raised);
  display: none;
}

.feedback-box.active {
  display: block;
  animation: fadeIn 0.25s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.feedback-heading {
  font-size: 0.9rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.5rem;
}

.feedback-heading.correct { color: var(--color-success); }
.feedback-heading.wrong { color: var(--color-danger); }

.feedback-text {
  font-size: 0.9rem;
  line-height: 1.55;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.ai-comparison-note {
  font-size: 0.82rem;
  background-color: var(--bg-canvas);
  border-left: 3px solid var(--accent-primary);
  padding: 0.5rem 0.75rem;
  border-radius: 0 4px 4px 0;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.next-btn-wrap {
  display: flex;
  justify-content: flex-end;
}

.next-btn {
  background-color: var(--accent-primary);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  padding: 0.65rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: background-color 0.15s ease;
}

.next-btn:hover {
  background-color: var(--accent-hover);
}

/* --- Scorecard / Results Final Screen --- */
.scorecard-panel {
  display: none;
  padding: 2rem 1.5rem;
  text-align: center;
}

.scorecard-panel.active {
  display: block;
}

.scorecard-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background-color: var(--color-success-bg);
  color: var(--color-success);
  margin-bottom: 1rem;
  font-size: 2rem;
}

.scorecard-title {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.scorecard-lead {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.score-tally-big {
  font-family: var(--font-serif);
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--accent-primary);
  margin-bottom: 0.5rem;
}

.score-stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.75rem;
  max-width: 580px;
  margin: 1.5rem auto 2rem;
  text-align: center;
}

.score-stat-box {
  background-color: var(--bg-surface-raised);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 0.75rem;
}

.score-stat-label {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
}

.score-stat-num {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  margin-top: 0.2rem;
}

.share-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.share-btn {
  background-color: var(--text-primary);
  color: var(--bg-surface);
  border: none;
  border-radius: 6px;
  padding: 0.7rem 1.3rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: opacity 0.15s;
}

.share-btn:hover {
  opacity: 0.9;
}

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

.share-btn-secondary:hover {
  background-color: var(--bg-subtle);
}

.toast {
  display: inline-block;
  background: var(--text-primary);
  color: var(--bg-canvas);
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
  font-size: 0.8rem;
  margin-top: 0.5rem;
  opacity: 0;
  transition: opacity 0.2s ease;
}

.toast.visible {
  opacity: 1;
}

/* --- Editorial Prose & Benchmark Report --- */
.prose {
  margin-top: 3rem;
}

.prose h2 {
  font-family: var(--font-serif);
  font-size: 1.65rem;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-subtle);
}

.prose h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.35;
  color: var(--text-primary);
  margin-top: 1.75rem;
  margin-bottom: 0.6rem;
}

.prose p {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.prose ul, .prose ol {
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
}

.prose li {
  margin-bottom: 0.4rem;
  line-height: 1.6;
}

.prose blockquote {
  border-left: 3px solid var(--accent-primary);
  padding: 0.6rem 1rem;
  background-color: var(--bg-surface);
  border-radius: 0 6px 6px 0;
  margin: 1.5rem 0;
  font-style: normal;
  color: var(--text-secondary);
}

/* --- Table: Benchmark Results --- */
.table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 1.5rem 0 2rem;
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  background-color: var(--bg-surface);
  box-shadow: var(--shadow-sm);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  text-align: left;
}

.data-table th, .data-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

.data-table th {
  background-color: var(--bg-surface-raised);
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

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

.data-table .num-col {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.data-table tr.highlight-human td {
  background-color: var(--color-success-bg);
  font-weight: 600;
  color: var(--color-success);
}

.data-table tr.highlight-top td {
  background-color: var(--accent-subtle);
  font-weight: 600;
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2.5rem 1rem 3rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  background-color: var(--bg-surface);
}

.footer-inner {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

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

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  list-style: none;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}