:root {
  --bg: #0a0a0a;
  --surface: #111111;
  --border: #222222;
  --accent: #c8ff00;
  --accent-dim: rgba(200, 255, 0, 0.12);
  --text: #f0f0f0;
  --text-muted: #666;
  --human: #00e5a0;
  --ai: #ff4d6d;
  --radius: 4px;
  --mono: 'Space Mono', monospace;
  --display: 'Syne', sans-serif;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

.noise {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 999;
  opacity: 0.03;
  background-repeat: repeat;
  background-size: 128px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.2rem 2rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: rgba(10,10,10,0.9);
  backdrop-filter: blur(12px);
  z-index: 100;
}

.logo {
  font-family: var(--display);
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: 0.15em;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.logo-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2s ease-in-out infinite;
}

nav { display: flex; gap: 1.5rem; }
nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  transition: color 0.2s;
}
nav a:hover { color: var(--accent); }

main {
  flex: 1;
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
  padding: 0 2rem 4rem;
}

section { padding: 5rem 0; border-bottom: 1px solid var(--border); }
section:last-child { border-bottom: none; }

h2 {
  font-family: var(--display);
  font-weight: 800;
  font-size: 2rem;
  margin-bottom: 2rem;
  letter-spacing: -0.02em;
}

.hero { padding-top: 6rem; }
.hero h1 {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(3rem, 10vw, 6rem);
  line-height: 1.0;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}
.hero h1 em {
  font-style: normal;
  color: var(--accent);
}
.subtitle {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.8;
  max-width: 500px;
  margin-bottom: 2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.9rem 1.6rem;
  background: var(--accent);
  color: #000;
  border: none;
  border-radius: var(--radius);
  font-family: var(--display);
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(200,255,0,0.25); }
.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn-outline:hover { background: var(--accent-dim); box-shadow: none; }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.8rem; margin-top: 0.5rem; }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-bottom: 1rem;
}
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
}
.stat-number {
  font-family: var(--display);
  font-weight: 800;
  font-size: 3.5rem;
  color: var(--accent);
  line-height: 1;
}
.stat-unit {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--accent);
  opacity: 0.6;
  margin-bottom: 0.5rem;
}
.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.6;
}
.stats-source {
  font-size: 0.65rem;
  color: var(--text-muted);
}

.quiz-intro {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}
.quiz-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}
.quiz-progress {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.quiz-progress-bar {
  height: 3px;
  background: var(--border);
  border-radius: 99px;
  margin-bottom: 1.5rem;
  overflow: hidden;
}
.quiz-progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 99px;
  transition: width 0.4s ease;
}
.quiz-question {
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}
.quiz-buttons {
  display: flex;
  gap: 1rem;
}
.quiz-btn {
  flex: 1;
  padding: 0.9rem;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--mono);
  font-size: 0.85rem;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}
.quiz-btn:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-dim); }
.quiz-btn.correct { border-color: var(--human); background: rgba(0,229,160,0.1); color: var(--human); }
.quiz-btn.wrong   { border-color: var(--ai); background: rgba(255,77,109,0.1); color: var(--ai); }
.quiz-feedback {
  margin-top: 1.2rem;
  padding: 1rem;
  border-radius: var(--radius);
  font-size: 0.8rem;
  line-height: 1.7;
}
.quiz-feedback.correct { background: rgba(0,229,160,0.08); border: 1px solid rgba(0,229,160,0.3); color: var(--human); }
.quiz-feedback.wrong   { background: rgba(255,77,109,0.08); border: 1px solid rgba(255,77,109,0.3); color: var(--ai); }

.quiz-result { text-align: center; padding: 2rem; }
.result-text {
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
  padding: 1.5rem;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}
.result-text.good  { border-color: var(--human); }
.result-text.okay  { border-color: var(--accent); }
.result-text.bad   { border-color: var(--ai); }

/* accordion :D */
.accordion { display: flex; flex-direction: column; gap: 0.5rem; }
.accordion-item { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.accordion-btn {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.2rem 1.5rem;
  background: var(--surface);
  color: var(--text);
  border: none;
  font-family: var(--mono);
  font-size: 0.9rem;
  cursor: pointer;
  text-align: left;
  transition: background 0.2s;
}
.accordion-btn:hover { background: #1a1a1a; }
.acc-icon { color: var(--accent); font-family: var(--display); font-weight: 800; min-width: 2rem; }
.acc-arrow { margin-left: auto; transition: transform 0.3s; }
.accordion-item.open .acc-arrow { transform: rotate(180deg); }
.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.16,1,0.3,1), padding 0.3s;
  font-size: 0.82rem;
  line-height: 1.8;
  color: var(--text-muted);
  padding: 0 1.5rem;
  background: var(--bg);
}
.accordion-item.open .accordion-body { max-height: 200px; padding: 1.2rem 1.5rem; }

footer {
  padding: 2rem;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.65rem;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
footer a { color: var(--text-muted); text-decoration: underline; }
footer a:hover { color: var(--accent); }

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.7); }
}

@media (max-width: 600px) {
  header { padding: 1rem 1.2rem; }
  nav { gap: 0.8rem; }
  main { padding: 0 1.2rem 3rem; }
  .quiz-buttons { flex-direction: column; }
}