:root {
  --bg: #0b1020;
  --bg-soft: #131a31;
  --panel: rgba(255, 255, 255, 0.9);
  --panel-strong: rgba(255, 255, 255, 0.98);
  --text: #122033;
  --muted: #53627a;
  --line: rgba(16, 24, 40, 0.09);
  --primary: #3558ff;
  --primary-dark: #2543d5;
  --ghost: #eef3ff;
  --success: #0f8a44;
  --success-bg: #ebfff3;
  --warning: #b26a00;
  --warning-bg: #fff6df;
  --danger: #bf2645;
  --danger-bg: #fff0f3;
  --shadow: 0 24px 60px rgba(4, 14, 35, 0.18);
  --radius-lg: 26px;
  --radius-md: 18px;
  --radius-sm: 14px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Inter', Arial, Helvetica, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(68, 97, 255, 0.2), transparent 32%),
    radial-gradient(circle at top right, rgba(137, 78, 255, 0.16), transparent 25%),
    linear-gradient(180deg, #0b1020 0%, #101831 100%);
  min-height: 100vh;
}

.page-shell {
  min-height: 100vh;
  padding: 28px 16px 48px;
}

.container {
  width: min(1120px, 100%);
  margin: 0 auto;
}

.panel {
  background: var(--panel);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.45);
  box-shadow: var(--shadow);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 18px;
}

.hidden {
  display: none;
}

.hero {
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.94), rgba(245, 248, 255, 0.88)),
    linear-gradient(135deg, rgba(53, 88, 255, 0.12), rgba(137, 78, 255, 0.1));
  overflow: hidden;
}

.hero-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 8px;
  font-size: 0.82rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--primary);
}

h1 {
  margin: 0;
  font-size: clamp(2.5rem, 5vw, 4.2rem);
  line-height: 0.98;
  letter-spacing: -0.04em;
}

h2 {
  margin: 0 0 10px;
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  letter-spacing: -0.03em;
}

h3 {
  margin: 0 0 10px;
  font-size: 1.06rem;
}

.lead {
  margin: 14px 0 0;
  max-width: 56ch;
  color: var(--muted);
  font-size: 1.08rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.hero-meta span {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(53, 88, 255, 0.08);
  color: #2844c7;
  font-size: 0.92rem;
  font-weight: 700;
}

.intro-grid,
.result-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 18px;
}

.clean-list {
  margin: 14px 0 0;
  padding-left: 1.2rem;
}

.clean-list li {
  margin-bottom: 8px;
}

.hint-box,
.result-box {
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--panel-strong);
  padding: 18px;
}

.btn {
  appearance: none;
  border: 0;
  border-radius: 14px;
  padding: 14px 18px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.14s ease, box-shadow 0.14s ease, background 0.14s ease, opacity 0.14s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}

.btn-primary {
  background: linear-gradient(180deg, #4a69ff 0%, #3558ff 100%);
  color: white;
  box-shadow: 0 12px 24px rgba(53, 88, 255, 0.24);
}

.btn-primary:hover {
  background: linear-gradient(180deg, #4563f3 0%, #2848eb 100%);
}

.btn-answer {
  background: white;
  color: var(--text);
  border: 1px solid rgba(53, 88, 255, 0.14);
}

.btn-answer:hover {
  box-shadow: 0 12px 24px rgba(16, 24, 40, 0.08);
}

.btn-ghost {
  background: var(--ghost);
  color: #2441c0;
}

.quiz-top {
  display: grid;
  grid-template-columns: 1fr minmax(180px, 280px);
  gap: 18px;
  align-items: end;
}

.progress-label {
  margin: 0 0 6px;
  color: var(--muted);
  font-weight: 700;
}

.category {
  margin: 0;
  color: var(--primary);
  font-weight: 700;
}

.progress-bar {
  width: 100%;
  height: 12px;
  border-radius: 999px;
  background: #e9eef8;
  overflow: hidden;
}

.progress-fill {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #3558ff 0%, #6d7dff 100%);
  transition: width 0.22s ease;
}

.question-note {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin: 22px 0;
}

.image-card {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 22px;
  overflow: hidden;
  background: white;
}

.image-wrap {
  aspect-ratio: 4 / 3;
  background: #edf2fa;
}

.image-card img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.image-card figcaption {
  padding: 14px 16px;
  text-align: center;
  font-weight: 800;
  border-top: 1px solid var(--line);
}

.answer-buttons {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.feedback {
  margin-top: 20px;
  padding: 18px;
  border-radius: 20px;
  border: 1px solid var(--line);
  background: white;
}

.feedback.correct {
  background: var(--success-bg);
  border-color: rgba(15, 138, 68, 0.18);
}

.feedback.incorrect {
  background: var(--danger-bg);
  border-color: rgba(191, 38, 69, 0.18);
}

.feedback.unsure {
  background: var(--warning-bg);
  border-color: rgba(178, 106, 0, 0.18);
}

.feedback-header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  margin-bottom: 8px;
}

.feedback-badge {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 800;
  background: rgba(255, 255, 255, 0.7);
}

.learning-point {
  margin: 10px 0 18px;
  font-weight: 700;
}

.result-header {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: end;
}

.result-score {
  margin: 0;
  font-size: 1.2rem;
  font-weight: 800;
}

.result-summary {
  max-width: 68ch;
  color: var(--muted);
  font-size: 1.03rem;
}

.subtle-note {
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: #f6f8fc;
  border: 1px solid var(--line);
  color: var(--muted);
}

.result-list,
.sources-list {
  margin: 0;
  padding-left: 1.2rem;
}

.result-list li,
.sources-list li {
  margin-bottom: 10px;
}

.contact-note {
  margin-top: 14px;
  color: var(--muted);
}

.sources-head {
  margin-bottom: 16px;
}

.sources-note {
  margin: 0;
  color: var(--muted);
}

.sources-list a,
.contact-note a {
  color: var(--primary-dark);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

@media (max-width: 880px) {
  .intro-grid,
  .result-grid,
  .quiz-top,
  .image-grid {
    grid-template-columns: 1fr;
  }

  .result-header {
    align-items: start;
    flex-direction: column;
  }
}

@media (max-width: 620px) {
  .panel {
    padding: 20px;
    border-radius: 22px;
  }

  .answer-buttons {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .feedback-header {
    flex-direction: column;
    align-items: start;
  }
}