:root {
  --bg-primary: #0a0a0b;
  --bg-card: #111113;
  --bg-tertiary: #18181b;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --border: #1e1e22;
  --border-hover: #2a2a2e;
  --accent: #f59e0b;
  --accent-hover: #d97706;
  --success: #22c55e;
  --radius: 8px;
}

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

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  opacity: 0.015;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9999;
}

.container {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

code {
  background: var(--bg-tertiary);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  font-size: 0.85em;
  color: #a5f3fc;
}

/* Hero */
.hero {
  padding: 4rem 0 2.5rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2.5rem;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-shadow: 0 0 40px rgba(255,255,255,0.06);
  margin-bottom: 0.75rem;
}

.hero .lead {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Section */
.section {
  margin-bottom: 3rem;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 1.25rem;
}

.section-header h2 {
  font-size: 1.35rem;
  font-weight: 700;
  text-shadow: 0 0 40px rgba(255,255,255,0.06);
}

.section-icon {
  width: 22px;
  height: 22px;
  color: var(--accent);
  flex-shrink: 0;
}

/* Badge */
.badge {
  display: inline-flex;
  padding: 0.15rem 0.55rem;
  border-radius: 4px;
  font-size: 0.72rem;
  font-weight: 600;
  white-space: nowrap;
}

.badge-provider {
  background: rgba(245,158,11,0.12);
  color: #fcd34d;
  border: 1px solid rgba(245,158,11,0.25);
}

/* Card */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.prereq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Tabs */
.tab-buttons {
  display: flex;
  gap: 0;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.tab-btn {
  padding: 0.5rem 1.25rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.15s;
}

.tab-btn:hover { color: var(--text-secondary); }

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-content { display: none; }
.tab-content.active { display: block; }

/* Code Block */
.code-block {
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 0.5rem;
  border: 1px solid rgba(255,255,255,0.06);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #1a1a2e;
  padding: 0.45rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
}

pre {
  background: #0d0d1a;
  padding: 0.75rem 1rem;
  overflow-x: auto;
  margin: 0;
}

pre code {
  background: none;
  padding: 0;
  color: #a5f3fc;
  font-size: 0.82rem;
  line-height: 1.7;
}

.copy-btn {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.72rem;
  font-family: inherit;
  transition: all 0.15s;
}

.copy-btn:hover {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.copy-btn.copied {
  background: var(--success);
  border-color: var(--success);
  color: white;
}

/* Step List */
.step-list { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 0.75rem; }
.step {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.step-num {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(245,158,11,0.15);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.75rem;
  flex-shrink: 0;
}

.hint {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin: 0.25rem 0 0.5rem;
}

/* Alert/Tip */
.alert {
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 0.75rem 1rem;
  margin: 0.75rem 0 0;
  background: rgba(245,158,11,0.06);
}

.alert p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin: 0;
}

.alert strong { color: var(--accent); }

/* Info Row */
.info-row {
  display: flex;
  gap: 2rem;
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.info-item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.info-label {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.info-value {
  font-size: 0.87rem;
  color: var(--text-secondary);
}

/* Table */
.table-wrap { overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  font-size: 0.87rem;
}

thead { background: var(--bg-tertiary); }
th {
  padding: 0.7rem 1rem;
  text-align: left;
  font-weight: 600;
  border-bottom: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--text-secondary);
}

td {
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
}

tr:last-child td { border-bottom: none; }
tr:hover td { background: rgba(255,255,255,0.02); }

.row-label {
  font-weight: 600;
  color: var(--text-primary);
}

.check-icon {
  width: 18px;
  height: 18px;
  color: var(--success);
}

/* Footer */
.site-footer {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  padding-bottom: 3rem;
}

.cta-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
  margin-bottom: 1.5rem;
}

.cta-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.cta-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--accent);
}

.cta-link svg {
  width: 18px;
  height: 18px;
}

.cta-link:hover { color: var(--accent-hover); }

.footer-copy {
  text-align: center;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px;
  height: 40px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all 0.2s;
  z-index: 50;
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

.back-to-top svg { width: 20px; height: 20px; }
.back-to-top.show { opacity: 1; visibility: visible; }
.back-to-top:hover { background: var(--accent-hover); transform: translateY(-2px); }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Responsive */
@media (max-width: 640px) {
  .hero { padding: 2.5rem 0 1.5rem; }
  .hero h1 { font-size: 1.5rem; }
  .prereq-grid { grid-template-columns: 1fr; }
  .container { padding: 0 1rem; }
  .info-row { flex-direction: column; gap: 0.75rem; }
  table { font-size: 0.78rem; }
  th, td { padding: 0.5rem 0.6rem; }
}