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

:root {
  --bg: #0f0a1a;
  --bg-elevated: #1a0f2e;
  --bg-card: #140d24;
  --bg-hover: #201535;
  --text: #f1e8ff;
  --text-secondary: #a89cc4;
  --text-muted: #6d5f8a;
  --accent: #a855f7;
  --accent-light: #c084fc;
  --accent-dark: #7c3aed;
  --danger: #e11d48;
  --border: #2a1f42;
  --border-light: #3a2a5a;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --max-width: 960px;
  --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --font-serif: Georgia, 'Times New Roman', serif;
  --font-mono: 'SF Mono', 'Fira Code', monospace;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  padding-top: 72px;
}

a {
  color: var(--accent-light);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--text);
}

/* ─── Container ─── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ─── Navigation ─── */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(15, 10, 26, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

nav .nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
  max-width: var(--max-width);
  margin: 0 auto;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: var(--text);
}

.nav-logo img {
  height: 36px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
  font-size: 14px;
  color: var(--text-secondary);
}

.nav-links a {
  color: var(--text-secondary);
  transition: color 0.2s;
}

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

/* ─── Hero ─── */
.hero {
  padding: 80px 0 60px;
  text-align: center;
}

.hero-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 24px;
  display: block;
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 3px;
  margin-bottom: 16px;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(40px, 6vw, 64px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text) 50%, var(--accent-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-dark), var(--accent));
  color: white;
  box-shadow: 0 4px 20px rgba(168, 85, 247, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 28px rgba(168, 85, 247, 0.45);
  color: white;
}

.btn-secondary {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--text);
  background: var(--bg-hover);
}

/* ─── Section ─── */
section {
  padding: 64px 0;
  scroll-margin-top: 80px;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 3px;
  margin-bottom: 12px;
}

.section-header h2 {
  font-family: var(--font-serif);
  font-size: clamp(28px, 3.5vw, 38px);
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.section-header p {
  color: var(--text-secondary);
  font-size: 16px;
  max-width: 600px;
  margin: 0 auto;
}

/* ─── Overview Grid ─── */
.overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.overview-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all 0.2s;
}

.overview-card:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.overview-card .card-number {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.overview-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.overview-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ─── Steps / How it Works ─── */
.steps-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 700px;
  margin: 0 auto;
}

.step-item {
  display: flex;
  gap: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  transition: all 0.2s;
}

.step-item:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.step-number {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent-dark), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: white;
}

.step-content h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
}

.step-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ─── Card Features ─── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  text-align: center;
  transition: all 0.2s;
}

.feature-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.feature-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, rgba(168,85,247,0.15), rgba(225,29,72,0.1));
  border: 1px solid var(--border-light);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
  color: var(--accent-light);
}

.feature-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ─── Card List Section ─── */
.card-list-showcase {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.card-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  transition: all 0.2s;
}

.card-item:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.card-item .card-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 8px;
}

.card-item h4 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}

.card-item p {
  font-size: 13px;
  color: var(--text-muted);
}

/* ─── Deep Dive ─── */
.deep-dive-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px 36px;
  max-width: 700px;
  margin: 0 auto;
}

.deep-dive-block h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text);
}

.deep-dive-block p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.deep-dive-block p:last-child {
  margin-bottom: 0;
}

.deep-dive-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--accent-light);
  transition: color 0.2s;
}

.deep-dive-link:hover {
  color: var(--text);
}

/* ─── FAQ ─── */
.faq-list {
  max-width: 700px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  transition: all 0.2s;
  cursor: pointer;
}

.faq-item:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.faq-item summary {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.faq-item summary::after {
  content: '+';
  font-size: 18px;
  color: var(--text-muted);
  transition: transform 0.2s;
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-item .faq-answer {
  margin-top: 12px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

/* ─── Primary Sources ─── */
.sources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.source-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  transition: all 0.2s;
}

.source-card:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.source-card .source-type {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 8px;
}

.source-card h4 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
}

.source-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.source-card a {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--accent-light);
}

/* ─── Divider ─── */
.section-divider {
  border: none;
  border-top: 1px solid var(--border);
  max-width: var(--max-width);
  margin: 0 auto;
}

/* ─── Footer ─── */
footer {
  padding: 40px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
  border-top: 1px solid var(--border);
}

footer a {
  color: var(--text-secondary);
}

footer a:hover {
  color: var(--text);
}

/* ─── Responsive ─── */
@media (max-width: 640px) {
  nav .nav-inner {
    flex-direction: column;
    gap: 12px;
    padding: 12px 0;
  }

  .nav-links {
    gap: 16px;
    font-size: 13px;
  }

  .hero {
    padding: 48px 0 40px;
  }

  .hero-actions {
    flex-direction: column;
  }

  section {
    padding: 40px 0;
  }

  .step-item {
    flex-direction: column;
  }

  .deep-dive-block {
    padding: 24px 20px;
  }

  .overview-grid,
  .features-grid,
  .card-list-showcase,
  .sources-grid {
    grid-template-columns: 1fr;
  }
}